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15 January 2011, Volume 15 Issue 3 Previous Issue    Next Issue

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Influence of exogenous hyaluronic acid on chondrogenic differentiation of rabbit bone marrow mesenchymal stem cells Kou Jian-qiang, Wang Chang-yao, Wang Ying-zhen 2011, 15 (3):  381-385.  doi: 10.3969/j.issn.1673-8225.2011.03.001 Abstract ( 235 )   PDF (1535KB) ( 416 )   Save BACKGROUND: Hyaluronic acid is the most important component of intra-articular synovial fluid and plays a very important role on the cell morphogenesis, but its effect on bone marrow mesenchymal stem cells (MSCs) in the repair of cartilage defects remains unclear. OBJECTIVE: To investigate the role of intra-articular environment to the MSCs by studying the influence of exogenous hyaluronic acid on proliferation and chondrogenic differentiation of rabbit bone marrow MSCs. METHODS: The rabbit MSCs were isolated and cultured in the method of whole bone marrow and adherent culture. The fourth passage of cells were used for the experiment. The experimental group cells were induced by hyaluronic acid solution, with transforming growth factor-β3 induced group served as a positive control. The negative control group was joined regular medium. The features of chondrocytes were identified by toluidine blue staining, immunohistochemistry and RT-PCR to detect the expression of collagen Ⅱ after 7, 14, 21 day’s induction respectively. RESULTS AND CONCLUSION: After induced by hyaluronic acid, the speed of cell proliferation slowed down. The cell morphology changed from long spindle to polygonal, oval. The extracellular matrix showed metachromasia with toluidine blue and positive with type Ⅱ collagen immunohistochemical staining. RT-PCR detection also showed the expression of type Ⅱ collagen mRNA. All the above showed the characteristics of cartilage cell differentiation. But their expressions were weaker than the positive control group. The results indicated that the exogenous hyaluronic acid can induce the rabbit MSCs differentiate to chondrocytes. But its capacity is weaker than transforming growth factor-β3. Therefore, the intra-articular environment plays a positive role in promoting chondrogenic differentiation of MSCs and supported that hyaluronic acid could be used as a matrix for cartilage tissue engineering. Related Articles | Metrics

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Comparison of pedicle fascial flap and absorbable biomembrane in constructing tissue engineering bone to repair rabbit bone defects Meng Xian-yong, Yang Xin-ming, Qi Zhi-min, Wang Yao-yi, Bai Rui 2011, 15 (3):  386-390.  doi: 10.3969/j.issn.1673-8225.2011.03.002 Abstract ( 209 )   PDF (1933KB) ( 370 )   Save BACKGROUND: Tissue engineering bone constructed using both pedicle fascial flap and absorbable biomembrane can effectively promote the bone defect repair, but there is not enough study about the comparison between them. OBJECTIVE: To observe the bone reparative effect of tissue engineering bone wrapped by pedicle fascial flap and by simple biomembrane. METHODS: A 1-cm bone defect model was produced in rabbit bilateral ulna middle segment and periosteum. Autologous red bone marrow was implanted in the osteoinductive absorbing material containing bone morphogenetic protein to prepare uncellular tissue engineering bone, which was then implanted into the bilateral bone defect areas. The left side was wrapped by pedicle fascial flap as the experiment group, while the right side was wrapped by simple absorbable biomembrane as the control group. At 4, 8, 12, 16 weeks after the operation, each group was examined by X-ray radiograph, gross morphology and histological examination, bone shape measurement analysis in the reparative area was performed, the biomechanical detection was done at 12 weeks to compare the repair of bond defect in two groups. RESULTS AND CONCLUSION: The experiment group was superior to the control group regarding the X-ray radiograph, gross morphology and histological inspection, the quantity and the forming speed of bone trabecula and cartilaginous tissues, the formation of mature bone structure, the remodeling of diaphysis structure, the recanalization of cavum ossis, the absorption and degradation of the implant, the ratio of new bone trabecula area to total reparative area and the final biomechanical strength (P < 0.05). The outcomes indicated that the technology of membrane guided bone regeneration using pedical fascial flap to repair large-segment bone defect can restrict the growth of fibrous connective tissue in the reparative process, and promote the effective and fast vascularization, accordingly accelerate the process and the effect of transforming implanted bone to autologous bone. Related Articles | Metrics

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Growth and osteogenesis potential of bone marrow-derived mesenchymal stem cells in nano-hydroxyapatite/collagen Mu Xiao-hong, Zhao Zi-yi, Xu Lin, Wang Shuo-ren, Zhu Ling-qun, Chen Jiang, Li Xiao-ping 2011, 15 (3):  391-394.  doi: 10.3969/j.issn.1673-8225.2011.03.003 Abstract ( 310 )   PDF (1192KB) ( 305 )   Save BACKGROUND: Nano-hydroxyapatite/collagen (nHAC) is a kind of nano-bone material prepared according to bionic principle, its micro-structure and compositions are closely similar to natural bone, has good biocompatibility. OBJECTIVE: To investigate the bonding of rabbit marrow-derived mesenchymal stem cells (MSCs) and nHAC cultured in vitro, and to explore the feasibility of constructing tissue-engineering bone. METHODS: Rabbit MSCs were isolated, cultured and purified in vitro, then rabbit MSCs of third generation were seeded onto the nHAC. Their adhesion situation was analyzed by laser confocal scanning microscope and scanning electron microscope at 3, 7, 20 days. RESULTS AND CONCLUSION: Rabbit MSCs were well combined with nHAC, cell growth could be seen under confocal scanning microscope and scanning electron microscope; nHAC can be served as a good scaffold, it can make MSCs stably grow. Rabbit MSCs grow adherently in nHAC, and show osteogenesis potential. Related Articles | Metrics

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Feasibility of eyelid reconstruction with acellular xenogenic dermal matrix Zhang Xiang-rong, Zhou Qiong, Xiao Wei, Liu De-wu, Peng Yan 2011, 15 (3):  395-398.  doi: 10.3969/j.issn.1673-8225.2011.03.004 Abstract ( 280 )   PDF (1366KB) ( 424 )   Save BACKGROUND: Reconstruction of posterior lamella of eyelid is an important and difficult issue in eyelid reconstruction, and tarsal substitute is the focus of the study. Xenogenic acellular dermal matrix as a new tissue engineering material, is being widely studied and applied in the field of burn and plastic surgery at home and abroad. OBJECTIVE: To observe histocompatibility and histopathological changes of xenogenic (porcine) acellular dermal matrix transplantation for eyelid reconstruction in rabbits. METHODS: Full skin at 20 cm×20 cm was stripped from healthy little white pigs, for preparation of xenogenic (porcine) acellular xenogenic dermal matrix. Model of rabbit tarsal defect was established in 8 New Zealand rabbits, then acellular dermal matrix was implanted. Samples of implanted materials were collected for histological examination at 1, 2, 3 weeks postoperation under light microscopy. RESULTS and CONCLUSION: There were no obvious rejection and eyelid deformation observed. One week after implantation, partial inflammatory cells invasion was seen with light microscopy, and the inflammatory cells were reduced noticeably at 2 weeks after implantation, at 3 weeks after implantation, normal fibrous tissue ingrew and gradually split, instead of collagen fibers implanted, the inflammation disappeared. With low immunogenicity, and guidance for the growth of new collagen, the xenogenic acellular dermal matrix may be an ideal material of tarsal substitbutes. Related Articles | Metrics

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Fabrication and properties of a novel tissue engineered scaffold for annulus fibrosus disci intervertebralis Yan Zhong-sheng, Xu Bao-shan, Yang Qiang, Xia Qun, Zhang Chun-qiu, He Jian 2011, 15 (3):  399-403.  doi: 10.3969/j.issn.1673-8225.2011.03.005 Abstract ( 278 )   PDF (1773KB) ( 452 )   Save BACKGROUND: Tissue engineering strategies to repair degenerated intervertebral disc are being developed to replace or regenerate the herniated nucleus pulposus. However, the tissue engineering of nucleus pulposus alone can not restore intact structure and function of intervertebral disc. Tissue engineering of annulus fibrosus is deemed as a major limiting factor for tissue engineered intervertebral disc treatment strategy. OBJECTIVE: To fabricate a natural acellular demineralized bone matrix gelatin and to verify the feasibility of it as a scaffold for annulus fibrosus tissue engineering. METHODS: Pig proximal femoral cancellous bone rings (external diameter 10 mm, internal diameter 5 mm, thickness 3 mm) were fabricated, then dealed with high-pressure water washing, degreasing, decalcification, decellularization and other related treatments. The ring scaffolds were investigated by gross, histological, light microscopy and scanning electron microscopy observations, as well as porosity measurement, water absorption rate and biomechanical analysis. Dog bone marrow mesenchymal stem cells were isolated and cultured, MTT test was also done to assess cytotoxicity of the scaffolds.  RESULTS AND CONCLUSION: The scaffold showed white, porous cancellous ring. The hematoxylin-eosin staining revealed that there were no cell fragments in the scaffolds. The light microscopy and scanning electron microscopy observations demonstrated that the novel porous scaffold had a good pore interconnectivity with (401.4±13.1) μm pore diameter, (62.12±1.52%) porosity and (409.77±11.34)% water absorption rate. The biomechanical test showed that the longitudinal elastic modulus was (47.75 ±6.32) kPa. The intrinsic cytotoxicity assessment of novel scaffolds using MTT test showed that there were no significant differences in the absorbance value between scaffold leaching liquid ad control DMEM culture solution, thus the scaffolds do not exert any cytotoxic effect on cells. Novel acellular demineralized bone matrix gelatin scaffold had good pore diameter and porosity, appropriate biomechanical character, non-toxicity and good biocompatibility, which make it a suitable candidate as an alternative scaffold for annulus fibrosus tissue engineering. Related Articles | Metrics

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Blood compatibility evaluation of the spherical porous chitosan microcarrier Zhang Rui, Han Bao-san, Peng Cheng-hong 2011, 15 (3):  404-408.  doi: 10.3969/j.issn.1673-8225.2011.03.006 Abstract ( 349 )   PDF (686KB) ( 429 )   Save BACKGROUND: Literature reported that most of microcarrier was solid and macroporous. Although surface area was significantly increased compared with two-dimensional microcarrier, it was far away from ideal three-dimensional environment. OBJECTIVE: To construct spherical porous chitosan microcarrier, and to evaluate the blood compatibility of the spherical porous chitosan microcarrier by hemolysis, coagulation, platelet count, platelet aggregation tests. METHODES: The concentration of 1%, 2%, and 3% spherical porous chitosan microcarrier were successfully constructed using liquid nitrogen freeze-drying technology. Healthy, adult, New Zealand Rabbits were selected, the blood compatibility of spherical porous chitosan microcarrier was evaluated by hemolysis, coagulation, platelet count, platelet aggregation tests. RESULTS AND CONCLUSION: The concentration of 1%, 2%, and 3% spherical porous chitosan microcarrier hemolysis rate was1.56%, 2.07%, 2.31%, less than 5%, and without hemolyticus. 3 spherical porous chitosan microcarrier concentrations of sample materials had no significant effect on rabbit blood time. There was no significant difference between 3 concentration of spherical porous chitosan microcarrier and sodium chloride negative control group (P > 0.05). 3 spherical porous chitosan microcarrier concentrations of sample materials had no significant effect on platelet count. There was no significant difference between the comparison of leaching liquor injection before and after and intragroup comparison (P > 0.05). The results have confirmed that the spherical porous chitosan microcarrier has no hemolyticus, coagulation, and platelet aggregation. It shows that the spherical porous chitosan microcarrier has good blood compatibility. Related Articles | Metrics

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Biocompatibility and mechanical properties of naturally derived and synthetic scaffolds for urethral reconstruction Feng Chao, Xu Yue-min, Zhu Wei-dong, Cui Lei, Chen Jie 2011, 15 (3):  409-412.  doi: 10.3969/j.issn.1673-8225.2011.03.007 Abstract ( 215 )   PDF (544KB) ( 514 )   Save BACKGROUND: Recently debates on what kinds of urethral repair and reconstruction of tissue engineering scaffolds are more suitable occurred constantly, its evaluation of biocompatibility and mechanical properties are also poorly reported. OBJECTIVE: To evaluate the mechanical properties and biocompatibility applied to urethral repair and reconstruction of a variety of biomaterials. METHODS: Small intestinal submucosa (SIS), bladder acellular matrix graft (BAMG), and acellular corpus spongiosum matrix (ACSM) were prepared by decellularization method; polyglycolic acid (PGA) scaffold was prepared by knitting method. Uniaxial tensile mechanical testing was conducted to determine biomechanical properties of each scaffold; the surface pore size of scaffold was determined by light microscopy and scanning electron microscopy. Cytotoxicity of various biomaterials was detected by MTT assay. Corporal cavernosum smooth muscle cells (CCMSc) were inoculated in all scaffolds, cell permeability was further assessed after 13 days cultured in vitro.  RESULTS AND CONCLUSION: Biomechanical evaluation showed that the detection results of ACSM in terms of elastic modulus and fracture strength was prior to other materials (P < 0.05). MTT assay showed that all the scaffolds were in support of normal cell growth and metabolism without obvious cytotoxicity. PGA showed the largest pore size in the scanning electron microscope (> 200 μm); meanwhile, the ACSM has different pore sizes in urethral (< 5 μm) and corpus cavernosum surfaces   (> 10 μm). Widespread distribution of cells could be observed in PGA 14 days after seeding. There was no obvious sign of cell penetration in BAMG and ACSM urethral surfaces. However, significant cell penetration growth performances in cavernosal surfaces of SIS and ACSM were observed. It is indicated that all scaffolds demonstrated good biocompatibility, which is similar to normal urethral tissue in terms of mechanical properties. However, ACSM has certain advantages in many parameters of mechanics and histology. Related Articles | Metrics

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A comparison between titanium surgical mesh and bionic nano-bone in anterior cervical decompression and fusion Yang Chao-lei, Wang Li-min, Liu Yi-lin, Tan Hong-yu, Wang Wei-dong 2011, 15 (3):  413-416.  doi: 10.3969/j.issn.1673-8225.2011.03.008 Abstract ( 331 )   PDF (717KB) ( 317 )   Save BACKGROUND: Nano-hydroxyapatite/polyamide as a new bone graft material is used in anterior cervical decompression and fusion, it not only reduces the complications after bone removal, and exhibits a stable graft fusion rate. OBJECTIVE: To study clinical effect of titanium surgical mesh versus nano-hydroxyapatite and polyamide composite (n-HA/PA66) in anterior cervical decompression and fusion for treatment of cervical sondylotic myelopathy. METHODS: A total of 48 cases of cervical spondylotic myelopathy were treated with anterior cervical subtotal corpectomy and fusion, titanium locking plates fixation, 26 with titanium surgical mesh, 22 with n-HA/PA66. The JOA grading system was done to evaluate neural functional restoration, and Cobb’s angle was measured to evaluate the change of cervical curvature.  RESULTS AND CONCLUSION: All 48 patients were operated successfully and followed up for 6-14 months. The JOA grading scores were greatly improved in both groups at 3 months postoperation compared with before operation, without significant differences between two groups; at 3 and 6 months postoperation, the Cobb’s angle of all patients had significant differences compared with immediately after operation, without significant differences between two groups; 2 cases were evidenced subsidence of titanium surgical mesh and loss of vertebral height after three months of operation. N-HA/PA66 bionic bone as a graft of anterior cervical fusion has good fusion rate, and could effectively maintain the biological alignment and cervical intervertebral height. The long-term effects depend on further follow-up. Related Articles | Metrics

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Release characteristics of ganciclovir-fibrin glue-amniotic membrane complex Cai Ming-ming, Zhao Min 2011, 15 (3):  419-422.  doi: 10.3969/j.issn.1673-8225.2011.03.010 Abstract ( 313 )   PDF (673KB) ( 551 )   Save BACKGROUND: In recent years, fibrin glue as a drug delivery carrier, has been attracting a growing attention. Ganciclovir is an effective broad-spectrum antiviral drug of viral keratitis. Therefore, we choose this drug in the initial exploration and research of drug delivery-fibrin glue-amniotic membrane. OBJECTIVE: To study the release characteristics of ganciclovir-fibrin glue-amniotic membrane and to explore a new method for clinical treatment of viral keratitis.  METHODS: In vitro study: fibrin glue compounded with ganciclovir and amniotic membrane to prepare the ganciclovir-fibrin glue-amniotic membrane complex and the in vitro release characteristics of ganciclovir was studied. In vivo study: ganciclovir-fibrin glue-amniotic membrane complex was transplanted on right eyes of New Zealand rabbits as experimental group, and 1 g/L ganciclovir dropped into left eye, 100 μL was given in 5 eyes every 2 hours as the control. The ganciclovir concentration in the aqueous humors was assayed by high performance liquid chromatography. RESULTS AND CONCLUSION: In vitro release study revealed that the accumulative release rate of ganciclovir was (45.67±5.32)% 24 hours after incubation and rose to (63.42±4.68)% 48 hours later. The release process went to a balance condition 96 hours later. Animal indicated that the ganciclovir level in aqueous gradually reduced along with time. The drug level was significantly higher for experimental group than control at 1 day (P < 0.05); during 2-3 days, the drug level in aqueous of experimental group was higher than control group without significant differences; the ganciclovir level in aqueous of experimental group was lower than that of control group at 4-5 days (P < 0.05). The ganciclovir-fibrin glue-amniotic membrane complex has a good sustained release property both in vitro and in vivo, it may be a new treatment of viral keratitis. Related Articles | Metrics

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Allograft of microencapsulated ovarian cells affects bone collagen metabolism in ovariectomized mice Guo Xiao-xia, Zhou Jin-ling, Xu Qing, Shi Xiao-lin 2011, 15 (3):  423-426.  doi: 10.3969/j.issn.1673-8225.2011.03.011 Abstract ( 213 )   PDF (649KB) ( 282 )   Save BACKGROUND: Gonad hormones are essential for the maintenance of skeletal integrity. The in vitro cultured ovarian cells can secrete estradiol and progesterone. Alginic acid-polylysine-alginic acid microcapsule provides a barrier between the graft and the recipient, thus promoting the survival of heterotransplants. OBJECTIVE: To explore the survival and secretion functions of allografted microencapsulated ovarian cells in ovariectomized mice and their effect on bone collagen metabolism after ovariectomy (OVX). METHODS: Ovarian cells separated from female Kunming mice (6 weeks old) were cultured and microencapsulated with alginic acid-polylysine-alginic acid. A total of 24 female Kunming mice (8 weeks old) were randomly divided into three groups (n=8): normal group: OVX was not performed; OVX group: OVX was performed; transplantation group: microencapsulated ovarian cells were transplanted into abdominal cavity after OVX. Estradiol and/or progesterone levels of the medium of microencapsulated ovarian cells and mice serum were determined by radioimmunoassay. Ⅰ type collagen fibers in the bone matrix were showed by Van Gieson staining. The concentrations of hydroxyproline, Ca, and P were measured in the left femurs of mice. RESULTS AND CONCLUSION: The concentrations of estradiol and progesterone in the culture medium were not significantly different between the cultured ovarian cells and microencapsulated ovarian cells. The serum estradiol concentration at 90 days after transplantation had no significant difference compared with that of normal group, whereas the serum estradiol concentration of the OVX group was significantly lower than that of the normal group. In the transplantation group, the distribution of collagen fibers was similar to that of the normal group determined by Van Gieson staining. In comparison to the normal group, the OVX group had less, thinner trabecular matrix, and fewer collagen fibers, more free trabecular terminals, and a thinner uncalcified osteoid matrix. The concentrations of Hyp, Ca, and P in the left femurs of the OVX group were lower than those of the normal group. Microencapsulated ovarian cells survive well after transplantation and secrete estrogen, and they can prohibit OVX-caused bone collagen fibers catabolism to some degree. Related Articles | Metrics

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Three-dimensional finite element analysis of bond strength by bracket base metallic wire mesh space Chen Di 2011, 15 (3):  427-430.  doi: 10.3969/j.issn.1673-8225.2011.03.012 Abstract ( 356 )   PDF (504KB) ( 494 )   Save BACKGROUND: Bond strength of the bracket is influenced by many factors in orthodontics, different bracket-base designs exert influences on bond strength, and the present experimental methods are not able to exactly describe the bond strength in view of quantitative research. OBJECTIVE: To construct a three-dimensional finite element model of the bracket-cement-tooth and to analyze the influence of bracket base metallic wire mesh space on bond strength. METHODS: A validated three-dimensional finite element model of the bracket-cement-tooth system was constructed with the ANSYS commercial software based on CT scanning image and standard wire arch bracket values. The stress distribution in different mesh space (0.2 mm and 0.4 mm) of the brackets was calculated under the same the shear force and twist force. RESULTS AND CONCLUSION: 0.2-mm mesh space had a significantly greater peak stress than 0.4-mm space, but the resistance to the destruction was lower than 0.4-mm space. The bigger the mesh space is, the larger the mesh area is, the stronger the resistance to destruction is, the better the bond strength becomes on condition that the retention form of the cement remains intact. Related Articles | Metrics

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Local application of fibrin glue carrying gatifloxacin Zhang Shou-ping, Cao Bin, Xiu Xiao-guang, Wu Bin-bin 2011, 15 (3):  431-435.  doi: 10.3969/j.issn.1673-8225.2011.03.013 Abstract ( 304 )   PDF (693KB) ( 298 )   Save BACKGROUND: Fibrin glue as a biological carrier of antibiotics, has been widely used in clinical work, but experimental study on fibrin glue in combination with the fourth generation of fluoroquinolone broad-spectrum antibiotic gatifloxacin has been rarely reported. OBJECTIVE: To evaluate the effects of fibrin tissue adhesive and gatifloxacin on preventing and treating local infection of soft tissues after wound and the safety of the local drug delivery system． METHODS: Standard local infection models were established in New Zealand healthy white rabbits, which were grouped randomly into experiment group, control group and blank group. Fibrin tissue adhesive and gatifloxacin were implanted into the local infection site in experiment group, gatifloxacin injected in control group and normal saline injected in blank group. Venous bloods of rabbit ear were collected before the operation and at 3, 7, 14 days after the operation, leukocyte counts of whole blood were determined respectively. The plasma level of gatifloxacin in experiment group was determined. Muscular tissues of lateral incision in experiment group were dislodged at 3, 7, 14 days after the operation to determine the level of gatifloxacin and histological examination. RESULTS AND CONCLUSION: The blank group were infected in two weeks and the incisions were red and edema after the operation; There were no incision pus in experiment group and control group. Leukocyte count at different postoperative time points in experiment group was lower than that in blank group (P < 0.01), the control group was significantly higher than experiment group at 7 and 14 days, lower than blank group (P < 0.01 or P < 0.05). The plasma level of gatifloxacin and the level of gatifloxacin of 1.5 cm muscular tissues were gradually reduced at 3, 7, 14 days (P < 0.05); Histological examination revealed there were a lot of inflammatory cells in the muscular tissues of blank group. There were less inflammatory cells in control groups at 3 and 7 days, and no inflammatory cells at 14 days. Less inflammatory cells were found in experiment group at 3 days and no at 7, 14 days. The fibrin tissue adhesive is one kind of good biological carriers in anti-infection drug delivery system, its combination with gatifloxacin can reduce blooding and reduce infection rate. Related Articles | Metrics

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Morphological changes of injured spinal cord following combined treatment of glial cell line-derived neurotrophic factor microspheres with NogoA and ChABC microspheres Zhang Yu, Song Yue-ming, Li Tao, Liu Li-ming, Zeng Jian-cheng 2011, 15 (3):  436-440.  doi: 10.3969/j.issn.1673-8225.2011.03.014 Abstract ( 330 )   PDF (1946KB) ( 392 )   Save BACKGROUND: The principle of promoting axonal regeneration is to improve the environment that inhibits axonal regeneration and to enhance the capacity of axonal growth, the main measures are the use of axonal growth inhibitory factor blockers and neurotrophic factors. Biodegradable microspheres loaded drugs is a method to provide local sustained release of drugs. OBJECTIVE: To evaluate the effect of glial cell line-derived neurotrophic factor (GDNF), NogoA and ChABC microspheres on the regeneration and functional recovery of rats following spinal cord injury from a view of pathomorphological point. METHODS: Adult SD rats were used to establish spinal cord transective injury models, and were randomly divided into 8 groups: normal control group; sham operation group; local saline group; GDNF group; GDNF microspheres group; NogoA microspheres group; ChABC microspheres group; ChABC, GDNF and NogoA microspheres group. In normal control group and sham operation group, there was no model established. Ten weeks after injury, tetramethylrhodamine dextran amine anterograde neuronal tracing, immunohistochemistry and image analysis of neurofilament protein 200, GFAP and growth associated protein 43 were performed to assess the neurological regeneration. RESULTS AND CONCLUSION: ChABC, GDNF, NogoA microspheres can upgrade the expression of neurofilament protein 200, GFAP and growth associated protein 43 at spinal cord injury site, thus the regeneration and repair after spinal cord injury are obvious. ChABC, GDNF, NogoA microsphere is better than GDNF microspheres for the treatment of spinal cord injury. ChABC, GDNF, NogoA microspheres can promote the regeneration and repair of rats with transected spinal cord injury and is better than GDNF microspheres. Related Articles | Metrics

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A novel method for preparing adherent hydroxyapatite coating on carbon/carbon composite surface Li Dong-mei, Xiong Xin-bo, Zou Chun-li, Ma Chu-fan 2011, 15 (3):  441-444.  doi: 10.3969/j.issn.1673-8225.2011.03.015 Abstract ( 380 )   PDF (1260KB) ( 338 )   Save BACKGROUND: At present, there are many methods for preparing hydroxyapatite (HA) coating on carbon/carbon composite surface, but the bonding strength between the prepared coating and the substrate is not high. OBJECTIVE: To propose a novel method for preparing HA coating with high bonding strength on carbon/carbon composite surface. METHODS: Firstly, monetite coating was deposited on carbon/carbon composite using induction heating technique, and then the monetite coating was converted to HA by hydrothermal method in ammonia solution. The morphology of the coating was observed under scanning electron microscopy, the critical load of HA coating was determined using scratch test, and shear strength was detected with extrusion method. RESULTS AND CONCLUSION: Using induction heat deposition method, dense block anhydrous dicalcium phosphate coating with grain structure was prepared in the carbon/carbon composite surface, and then transformed into dense HA coating with good crystals by hydrothermal method. The critical load of HA coating is 13.31 N and shear strength is 47 MPa. Related Articles | Metrics

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Effect of a new anti-reflection, anti-fogging nano-film on surface modification of optical glasses Li Jian, Liu Jia-yi, Zhang Yang-de 2011, 15 (3):  445-449.  doi: 10.3969/j.issn.1673-8225.2011.03.016 Abstract ( 400 )   PDF (2020KB) ( 809 )   Save BACKGROUND: We use the addition polymerization of vinyl double bond to surface modify transparent substrate, and make a new film that has more ideal performances, such as fastened binding force, high hydrophilicity and enhanced transmittance. OBJECTIVE: To prepare a stable optical anti-fogging coating and high-quality anti-reflective characteristics by surface modification. METHODS: Anti-reflective and high-hardness Si-O-Si network structure precursor was made by tetraethyl orthoslicate, vinyl triethoxy silane, ethanol, HCl and H2O with the sol-gel method. The nano-film was prepared using addition polymerization theory, by using Si-O-Si as solvent, mixing ammonium acrylate, ammonium methacrylare and ammonium persulfate together, and using 2-hydroxyethyl methacrylate, methyl methacrylate as auxiliary functional groups. The structure was determined by fourier transform infrared spectroscopy and X-ray diffraction, the transmittance was assayed with UV spectrophotometer before and after coating, surface structure was measured by scanning electron microscopy, the particle size, film hardness and water contact angle were measured. RESULTS AND CONCLUSION: The hydrophilic anti-flogging nano-film not only had Si-O-Si network structure, but also had polymeric hydrophilic groups. The maximum transmittance was 94.6%, which mean a good transmittance of the film. The particle size of nano-film was (265.0±43.8) nm in diameter; the water contact angle was 14.5°, which showed good hydrophilicity. The coating hardness was 6 H, and the binding degree was about 95.1%. The nano-film had -CH = CH2 bond in the Si-O-Si network structure, therefore, it could connect with hydrophilic groups. As soon as the water droplet contacted the surface covered with the nano-film, it would spread over the surface, suggesting that a high transmittance surface would be achieved. Besides high transmittance and hardness, this film had other properties such as antireflection and antifogging. The preparation technology is feasible, and the quality controlling method is simple and reliable. Related Articles | Metrics

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Effects of nano-zirconium dioxide-toughened hydroxyapatite bioceramics on proliferation and differentiation of rabbit bone marrow stromal cells Tang Yue-jun, Wang Xin-ling, Zhou Zhong-hua, Lü Chun-tang 2011, 15 (3):  450-452.  doi: 10.3969/j.issn.1673-8225.2011.03.017 Abstract ( 248 )   PDF (820KB) ( 268 )   Save BACKGROUND: Research group has performed some preliminary studies pertaining to zirconia toughened nano-hydroxyapatite (HA-ZrO2) bioceramics, mainly in the biomechanical compatibility, chemical stability, and biocompatibility. Among them, in vitro cell culture experiments are controllable and repeatable, can well reflect the material's biocompatibility. OBJECTIVE: To study the influence to the growth and differentiation of rabbit bone marrow stromal stem cells by HA-ZrO2 or HA materials. METHODS: The rabbit bone marrow stromal stem cells were cultured in beccos modified eagle’s medium (DMEM) containing 20% fetal bovine serum, the subsequent cell passage was cultured in conditioned medium containing dexamethasone, beta-sodium glycerophosphate and ascorbic acid. The third passage osteoblasts were cultured in cell culture plate with materials at 1.0×108/L. The proliferation of all the cultured cells were observed at 1-10 days under inverted phase contrast microscope and the curve of cell-growth was plotted. The activity of alkaline phosphatase was detected. At 6 days of the culture, cells and composite materials were fixed with paraformaldehyde and observed under scanning electron microscope. RESULTS AND CONCLUSION: MTT assay showed the growth curve of cells cultured in two materials had no significant difference. The combined culture of rabbit bone marrow stromal cells can maintain normal function of secreting alkaline phosphatase. Electron microscopy photographs also confirmed the cell adhesion on two kinds of materials. HA-ZrO2 and HA show no adverse effect on the growth and differentiation of osteoblasts, with excellent compatibility. Related Articles | Metrics

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In vitro antibacterial test of the surface antibacterial coating of a new nano-silver/polyurethane biliary stent He Wei, Wang Xiang, Gao Ying, Liang Jun-cai, Yu Ting-ting, Fan Zhi-ning 2011, 15 (3):  453-456.  doi: 10.3969/j.issn.1673-8225.2011.03.018 Abstract ( 376 )   PDF (1319KB) ( 694 )   Save BACKGROUND: Biliary stents have been widely used in a variety of benign and malignant bile duct stricture as a palliative treatment. Its short-term efficacy is significant, but long-term use is limited by stent restenosis.  OBJECTIVE: To produce a new antibacterial coating used in biliary stent by means of nano-silver/polyurethane, and to test in vitro antibacterial properties. METHODS: Firstly, composite materials were made of nano-silver and polyurethane by in situ reduction method. Antibacterial test was used to detect in vitro antibacterial properties against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterococci of three groups: experimental group (nano-silver/polyurethane), positive control group (filter paper soaked in silver nitrate solution) and negative control group (polyurethane), antibacterial zone diameters were measured and analyzed. RESULTS AND CONCLUSION: The difference was not significant between experimental group and positive control group in the antibacterial effect on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterococci. Nano-silver/polyurethane composite has good antibacterial property and better stability. Related Articles | Metrics

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Quaternary ammonium salt chitosan nanoparticles encapsulate parathyroid hormone-related peptide nanoparticles Luo Ju-ying, Guo Wei-chun, Zhao Sheng-hao, Zhao Zheng-ju, Tang Jin1, Yu Ling 2011, 15 (3):  457-460.  doi: 10.3969/j.issn.1673-8225.2011.03.019 Abstract ( 315 )   PDF (1273KB) ( 305 )   Save BACKGROUND: Small-scale studies have shown that low-dose, intermittent application of parathyroid hormone related peptide can effectively treat osteoporosis in postmenopausal women. But it is disadvantageous due to prone to degrade, short half-life and expensive cost, therefore it is necessary to modulate the release speed of parathyroid hormone related peptide using controlled-release system and to improve the biological efficiency. OBJECTIVE: To prepare a novel nanoparticles for carrying drugs, and to investigate encapsulation efficiency and in vitro release characteristics of parathyroid hormone-related peptide. METHODS: Quaternary ammonium salt of chitosan nanoparticles were prepared based on ionic gelation, and the characteristics were observed by fourier transform infrared spectroscopy and transmission electron microscopy, and the encapsulation efficiency and release characteristics in vitro of the nanoparticles were determined. RESULTS AND CONCLUSION: Chitosan quaternary ammonium salt and sodium tripolyphosphate were mixed to form the nanoparticles when the quantity of chitosan quaternary ammonium salt and sodium tripolyphosphate was 5:1-2:1 under stirring at room temperature. The nanoparticles size was about 100-180 nm, regular sphere. With the increase of the parathyroid hormone-related peptide concentration, the drug encapsulation efficiency increased but the loading capacity reduced. The drug-loading nanoparticles showed slow release characteristics in PBS solution in vitro. Related Articles | Metrics

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In vitro corrosion behavior of nano-multilayered TiN/Ti coated NiTi alloy Shao An-liang, Cheng Yan, Xi Ting-fei, Zhou Yi, Zhou Liang, Wan Zi-yi 2011, 15 (3):  461-464.  doi: 10.3969/j.issn.1673-8225.2011.03.020 Abstract ( 289 )   PDF (1268KB) ( 526 )   Save BACKGROUND: A nickel-titanium alloy with super-elastic, shape memory effect and good fatigue resistance has become the optimal choice for the core component of occluder stent, but the nickel-titanium alloy containing 50% nickel has a controversial biocompatibility. OBJECTIVE: To study anti-corrosion property of occluder nickel-titanium alloy before and after multi-arc ion plating by static immersion in vitro and electrochemical methods. METHODS: Nano-gradient TiN/Ti multilayered films had been fabricated on nickel-titanium alloy by multi-arc ion plating. Nickel ion concentration was investigated by static immersion in PBS for one month. The anti-corrosion property of nickel-titanium alloy before and after surface modification was measured by open circuit potential-time curve and polarization curve. RESULTS AND CONCLUSION: Nickel-titanium alloy had been released and reached the maximum values during one-month immersion period, while no nickel ion was found released from the TiN/Ti multilayered coated NiTi alloy. Open circuit potential-time curves and polarization curves show that the corrosion resistance of nickel-titanium alloy has been greatly improved after modification. Related Articles | Metrics

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Preparation of low-molecular-weight hyaluronan liposomes and their percutaneous penetration Zhang Wen-qiang, Huang Yue-shan 2011, 15 (3):  465-467.  doi: 10.3969/j.issn.1673-8225.2011.03.021 Abstract ( 475 )   PDF (875KB) ( 2168 )   Save BACKGROUND: Hyaluronic acid is a versatile polymer material, in practical applications, due to its large molecular weight, percutaneous absorption effect is not satisfied, the use of liposomes as a carrier can improve its transmission effect, with a good application prospect. OBJECTIVE: To study the percutaneous penetration of the liposomes carrying low-molecular-weight hyaluronic acid. METHODS: Low-molecular-weight hyaluronan liposomes were prepared through thin films. Orthogonal experiment was design, and percutaneous penetration was study by snake slough. RESULTS AND CONCLUSION: The low-molecular-weight hyaluronan liposomes could enwrap more hyaluronic acid when the temperature is 35 ℃, the ratio of cholesterol and lecithin is 0.15∶1, the ratio of hyaluronic acid and lecithin is 0.03∶1, and the pH of hydration medium PBS is 7.5. Hyaluronic acid could penetrate the snake slough more easily when they were enwrapped by liposome, and the percutaneous penetration of hyaluronic acid was improved. Related Articles | Metrics

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Structure and extraction conditions of sericin protein Zhang Yao-qin, Chen Zhong-min, Zhang Yan-dong, Chen Peng 2011, 15 (3):  468-472.  doi: 10.3969/j.issn.1673-8225.2011.03.022 Abstract ( 413 )   PDF (514KB) ( 985 )   Save BACKGROUND: Sericin has been widely used as a biomaterial. The properties and function of sericin may be changed with different extraction methods and conditions, thus affecting the biological properties. OBJECTIVE: To observe the changes of sericin molecular conformation using different materials and under different preparation conditions. METHODS: Sericin protein was extracted under the same extraction conditions from cocoon shell (Jk1, Jk2, Jk3) and cocoon outer floss (Jy4), respectively. Sericin protein peptide from cocoon shell (Jkmj5) was prepared by neutral proteinase. It was characterized by the molecular weight determination, infrared spectroscopy, amino acid composition and content measurement, solubility test, respectively RESULITS AND CONCLUSION: When sericin extracted from cocoon shell and cocoon outer floss, there were significant differences in molecular weight determination, amino acid composition and content measurement. The molecular weight determination of Jk1, Jk2, Jk3 was about 66 200-130 000, respectively, while that of the Jy4 was about 43 000-130 000. The aspartic acid, serine, threonine and glycine contents decreased, while glutamic acid and lysine increased significantly in sericin extracted from cocoon outer floss compared with that extracted from cocoon shell. By the infrared spectroscopy, Jk1, Jk2, Jk3, Jy4 were mostly α-helix structure type, and the random coil structure increased in Jy4. The dissolving property of Jy4 was almost twice that of Jk1, Jk2, Jk3. Jkmj5 was the structure of corners and random coil mainly. The sericin protein extracted on the same extraction materials and conditions has similar composition and stable properties. Related Articles | Metrics

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Biological features of C3A hepatocytes versus L-02 immortalized hepatocytes under hypothermic stored condition Li An-quan, Li Qing-yong, Zhang Qing-hua, Jiang Zhi-xin, Sha Hang, Gao De-lu, Gao Yi 2011, 15 (3):  473-477.  doi: 10.3969/j.issn.1673-8225.2011.03.023 Abstract ( 460 )   PDF (724KB) ( 407 )   Save BACKGROUND: A large number of functional liver cells is the core of bioartificial liver. It is the existing research focus of bioartificial liver to explore a reliable method of cryopreservation of liver cells and to construct liver cell bank. OBJECTIVE: To compare the biological characteristics of C3A hepatocytes that has entered clinical Ⅲ stage test and L-02 immortalized hepatocytes stored in UW solution at 4 ℃. METHODS: The C3A hepatocytes and L-02 hepatocytes were adherent cultured, digested by 0.25% trypsinization, prepared into cell suspension, and stored in UW solution. At 0, 24, 48, 72 hours of hypothermic storage (4 ℃), the cell viability rate and cell apoptosis rate were measured using flow cytometry. Lactate dehydrogenase and aspartate aminotransferase release, the ability of hepatocytes to synthesize urea and secrete albumin were also determined. RESULTS: The cell viability of C3A hepatocytes and L-02 hepatocytes was degraded following the time, but the cell viability of C3A hepatocytes was higher than L-02 hepatocytes (P < 0.01). Cell apoptosis was increased, but there was no difference between C3A hepatocytes and L-02 hepatocytes after 48 hours (P > 0.05). The lactate dehydrogenase and aspartate aminotransferase release were ascended, but the release of C3A hepatocytes was lower than L-02 hepatocytes (P < 0.01). The ability of hepatocytes to secrete albumin was decreased, but the ability of C3A hepatocytes was better than L-02 hepatocytes   (P < 0.01). The ability of hepatocytes to synthesize urea was also decreased, however, the ability of L-02 hepatocytes was better than C3A hepatocytes (P < 0.01). Results demonstrated that, the time of the C3A hepatocytes and L-02 hepatocytes which are hypothermicaly stored (4 ℃) in UW solution should not exceed 48 hours. The artificial liver prepared by C3A hepatocytes is more suitable for the liver function failure combined low albuminaemia, and artificial liver prepared by L-02 hepatocytes fits the liver function failure combined hepatic encephalopathy. Related Articles | Metrics

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Bone marrow mesenchymal stem cells combined with injectable fibrinous gel transforming growth factor-beta 1 transplantation for treatment of intervertebral disc degeneration Wu Jian, Yang Jin-hua, Yang Zong-hua, Wang Xiao-lin, Zhang Wei, Shen Fei 2011, 15 (3):  478-482.  doi: 10.3969/j.issn.1673-8225.2011.03.024 Abstract ( 359 )   PDF (708KB) ( 444 )   Save BACKGROUND: The main part of fibrinous gel is liquid state before mixing with catalytic agent, and it is injectable, solidifying after mixing them, this is similar with nucleus pulposus, the solidify time is strongly controllable, and it is advantageous to implant in nucleus pulposus as a carrier of mesenchymal stem cells (MSCs). OBJECTIVE: To explore the feasibility of bone marrow MSCs compound injectable fibrinous gel transforming growth factor-β1 (TGF-β1) transplantation on inhibiting intervertebral disc degeneration. METHODS: New Zealand white rabbits are randomly divided into three groups: degeneration model group, pure fibrinous gel group and MSCs+fibrinous gel group. The degeneration models were produced in three groups by means of puncturing the annulus fibrosus, then the pure fibrinous gel group and MSCs + fibrinous gel group were respectively transplanted with fibrinous gel TGF-β1 complex and MSCs + fibrinous gel TGF-β1 complex. CR, MRI and pathological examinations were carried out at 4, 8 and 12 weeks after transplant. RESULTS AND CONCLUSION: The disc height index obviously decreased in the degeneration model group and the pure fibrinous gel group, which is positively correlated with time; but the index decreased slowly in MSCs + fibrinous gel group (P < 0.01). An immunohistochemistry study and a histological examination indicated a decreasing quantity of the nucleus pulposus cells and the content of type Ⅱ collagen in the degeneration model group, as well as an obviously increasing rate of cells apoptosis. The pure fibrinous gel group was similar to the degeneration model group. The MSCs + fibrinous gel group showed an obviously increasing quantity of nucleus pulposus cells and type Ⅱ collagen content compared with the degeneration group and the pure fibrinous gel group, while the cells apoptosis rate decreased. Bone marrow MSCs in combination with fibrinous gel TGF-β1 can prohibit intervertebral disc degeneration, but pure fibrinous gel TGF-β1 cannot. Related Articles | Metrics

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Safety evaluation of bone matrix gelatin with autologous peripheral blood stem cells to repair bone defects Zhang Xiao-zhou, Zou San-ming, Feng Hua-ming, Huang Du, Kang Zhao-li 2011, 15 (3):  483-486.  doi: 10.3969/j.issn.1673-8225.2011.03.025 Abstract ( 203 )   PDF (561KB) ( 345 )   Save BACKGROUND: Animal experiments confirmed that the immunological rejection of bone matrix gelatin (BMG) is small after transplantation and BMG can promote cartilage and bone formation in the early stage. OBJECTIVE: To study the feasibility of repairing segmental bone defects by autologous peripheral blood stem cells (APBSC)/BMG. METHODS: The patients with bone defect were divided into 2 groups in accordance with the principle of voluntary. APBSC/BMG group: APBSC/BMG was installed in the bone ends, BMG group: BMG was installed in the bone ends. In addition, external and internal fixations were performed. The positive and lateral X-ray films of the bone defect were taken after surgery. RESULTS AND CONCLUSION: In APBSC/BMG group, a great amount of new irregular bone fibrous tissues, cartilage, bone cells, bone tissues and bone trabeculae are on the surface of fracture end, with medullary cavity formed. In BMG group, a great amount of fibrous tissues, a less of new irregular bone fibrous tissues and skeletal muscles were seen on the surface of fracture, accompanied by multinucleated giant cells and a few inflammatory cells. Bony callus tissues were observed at the edge of defect area. The average cicatrization time of APBSC/BMG group was shorter than BMG group (P < 0.05). There were no obvious adverse reactions found during the treatment. APBSC/BMG has good biocompatibility, absorbability and bone induction in the process of bone defect healing. The effect of APBSC/BMG is better than BMG. Related Articles | Metrics

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Efficacy of homemade biodegradable rapamycin drug-eluting stent implantation: Compared with bare-metal stents Zhao Hong-li, Li Lu, Wang Shuai, Li Chun 2011, 15 (3):  487-490.  doi: 10.3969/j.issn.1673-8225.2011.03.026 Abstract ( 316 )   PDF (578KB) ( 368 )   Save BACKGROUND: The drug-eluting stent (DES) can obviously decrease restenosis rate, but permanent polymer coating impedes the process of vascular endothelial and promotes restenosis, cause many complications such as late thrombosis at the same time of the inhibition of vascular smooth muscle cells proliferation. OBJECTIVE: To investigate the long-term outcomes and safety after homemade biodegradable DES implantation for patients with coronary artery disease and diabetes mellitus, and compare with bare-metal stents. METHODS: A total of 136 consecutive patients of coronary artery disease and type-2 diabetes mellitus, receiving homemade biodegradable DES (EXCELTM) implantation following percutaneous coronary angioplasty were studied as DES group; A total of 87 patients with coronary artery disease and type-2 diabetes mellitus treated with bare-metal stents were included as control group. All patients were identified and followed up at least 12 months. The differences of major adverse cardiovascular events were recorded and the patients were rechecked undergoing quantitative coronary angiography. RESULTS AND CONCLUSION: A total 129 patients in DES group and 83 patients in control group accomplished follow-up at a mean time of (13.5±3.5) months. There were 8 patients and 12 patients in DES group and control group appeared major adverse cardiovascular events with significant difference between the two groups (P=0.045), the rate of target vessel revascularization and repeated angina were higher control group than in BMS group (P < 0.05). The late loss index and restenosis rate with DES were lower when underwent quantitative coronary angiograph follow-up (P < 0.05). The restenosis and major adverse cardiovascular events were reduced by homemade biodegradable DES in coronary heart disease patients with diabetic mellitus, and DES is safe and effective with improved long-termed prognosis. Related Articles | Metrics

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Effect of biological mesh on hiatal hernia repair: One-year follow-up Yao Guo-liang, Yao Qi-yuan, Hua Rong, Yu Jian-ping 2011, 15 (3):  491-494.  doi: 10.3969/j.issn.1673-8225.2011.03.027 Abstract ( 433 )   PDF (528KB) ( 516 )   Save BACKGROUND: Although laparoscopic hiatal hernia repair had achieved good therapeutic effect, there is a debate addressing whether the biological mesh was used for surgery. OBJECTIVE: To analyze the effect of laparoscopic hiatal hernia repair with biological mesh. METHODS: To retrospectively analyze clinical data of 57 patients with esophageal hiatal hernia, all of whom were accepted surgical treatment at Huashan Hospital Affiliated to Fudan University from November 2006 to June 2009, including 24 cases with simple diaphragm feet suture and Nissen fundoplication (control group), 33 cases with simple diaphragm feet suture and Nissen fundoplication were undergoing mesh reforcement simultaneously (experimental group). The therapeutic results of laparoscopic hiatal hernia repair were compared and analyzed with or without mesh. RESULTS AND CONCLUSION: During 1 year follow-up, there was no significant difference between the control and experimental groups, including recurrence rate, patient satisfactory and symptom control (P  > 0.05). Compared with the control group, the intraoperative and postoperative complications were not increased in experimental group; meanwhile, operation interval and hospital stay were not significantly longer either (P > 0.05). The short-term follow-up results showed that laparoscopic hiatal hernia repair with mesh was safe and effective, but indications should be strictly controlled. Related Articles | Metrics

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Repair of bone exposed wounds using artificial dermis in 23 cases Du Wei-li, Zhou Ye-ping, Tian Peng, Zhang Guo-an 2011, 15 (3):  495-498.  doi: 10.3969/j.issn.1673-8225.2011.03.028 Abstract ( 414 )   PDF (691KB) ( 391 )   Save BACKGROUND: In recent years, artificial dermis has been reported to repair bone exposed wound, but the treatment effect remains unclear.　 OBJECTIVE: To evaluate the therapeutic effect of artificial dermis in repairing bone exposure in 23 cases. METHODS: A total of 23 patients with bone exposure were selected from the Department of Burns, Beijing Jishuitan Hospital, including 18 males and 5 females. Patients underwent debridement and artificial dermal transplantation, followed by split thickness autoskin transplantation. The survival of artificial dermis and split thickness autoskin was observed, as well as scar hyperplasia at the skin donor site.  RESULTS AND CONCLUSION: The bone exposed wounds of 22 patients were completely recovered and scar formation were not observed at donor site after surviving of artificial dermis and split thickness autoskin, only skull exposure was partially covered in one femal patient. Artificial dermis has a good therapeutic effect in repairing bone exposure. Related Articles | Metrics

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Negative electrostatic charge-polytetrafluoroethylene polymer membrane combined lumbar traction for treatment of radicular back pain Bai Xue, Shi Chao, Liu Jie, Zhang Kai-bo, Wen Min 2011, 15 (3):  499-502.  doi: 10.3969/j.issn.1673-8225.2011.03.029 Abstract ( 339 )   PDF (720KB) ( 628 )   Save BACKGROUND: The negative electrostatic charge polymer materials, porous polytetrafluoroethylene (PTFE) electret film affixed to the surface of the skin surface can form a high-voltage static electricity and negative electrostatic field, and neutralize the accumulation of positive charge in the lesion. OBJECTIVE: To investigate the negative electrostatic charge-PTFE polymer membrane in combination with lumbar traction for the treatment of radicular back pain. METHODS: A total of 120 cases of radicular low back pain were randomly divided into three groups: traction group, negative electrostatic charge-PTFE polymer membrane group and combination group. Patients with combined treatment were treated with two methods together. One month later, three groups of patients were observed through the Japanese Orthopaedic Association (JOA) to assess the efficacy. RESULTS AND CONCLUSION: One month after treatment, the JOA scores of three groups was combination group > traction group > negative electrostatic charge-PTFE polymer membrane group, the differences were statistically significant (P < 0.05). The improved index and improvement rate of low back pain in patients of combination group were significantly higher than the other two groups. The negative electrostatic charge-PTFE polymer membrane in combined with lumbar traction is superior to negative electrostatic charge-PTFE polymer membrane treatment alone for radicular back pain. Related Articles | Metrics

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Application of polylactic acid based medical materials in tissue engineering and controlled release system Zhang Wen-long, Wang Yong, Bao Yu-cheng, Zhang Jin-jin 2011, 15 (3):  503-506.  doi: 10.3969/j.issn.1673-8225.2011.03.030 Abstract ( 259 )   PDF (598KB) ( 417 )   Save BACKGROUND: Polylactic acid (PLA) and its copolymers have good biocompatibility and biodegradability, because of good physico-mechanical properties and good thermal forming properties, as well as final degradation product is H2O and CO2, PLA has been widely studied and applied in tissue engineering and drug delivery areas. OBJECTIVE: Although the PLA and its copolymers have been studied and applied in tissue engineering and drug delivery area of sustained-release preparations. This study aims to investigate the application as a scaffold and a drug carrier material in bone defects caused by bone tuberculosis through reviewing the documents. METHODS: A computer-based online search of Medline database (1993-01/2010-06) and CNKI Database was performed using the key words of “Tissue engineering, drug delivery, sustained release degradation, lactic acid, glycolic acid, bone tuberculosis” in English and in Chinese. RESULTS AND CONCLUSION: A total of 157 documents were screened out. Repetitive research was excluded, after reading titles and abstracts, 31 literatures were included in analysis. PLA and its copolymers as bone tissue engineering scaffolds are conducive to the growth of osteocytes, and are superior to traditional materials of bone repair. As a drug carrier, they sustained-release degrade in vivo to play the best efficacy, can reduce the toxicity of drugs to the body especially liver and kidney. But few studies report its role as both a scaffold and a drug carrier. Related Articles | Metrics

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Green chemical synthesis of poly(lactic acid) based biodegradable polymers Xu Wen-shu, Luo Xiang-lin 2011, 15 (3):  507-510.  doi: 10.3969/j.issn.1673-8225.2011.03.031 Abstract ( 276 )   PDF (667KB) ( 561 )   Save BACKGROUND: Poly(lactic acid) has excellent biocompatibility and biodegradability, thus it has been widely used in many biomedical fields, such as drug delayed release, surgical suture, tissue engineering scaffold and bone substitutes. Routine synthesis requires the use of solvent, showing low production efficacy and high cost. OBJECTIVE: Non-solvent green chemical synthesis of poly(lactic acid) based biodegradable materials via direct condensation polymerization and chain extension in melt state were reviewed. METHODS: A computer-based online search of SCI-Expanded database (1995-01/2010-06) and China Academic Journal Network Publishing Database was performed for related articles with the key words of “poly (lactic acid), diisocyanate” in English and in Chinese. A total of 130 articles regarding the lactic acid polycondensation/diisocyanate chain extension in melt state, including 39 Chinese papers and 91 English ones. Articles with duplicated content and poor experimental results were eliminated, finally 32 articles met the criteria were included. RESULTS AND CONCLUSION: The biodegradable polylactic acid-based polyurethane materials with different molecular weights and properties can be prepared by lactic acid melt polycondensation/diisocyanate melt chain extension with green chemical method using non-solvent, through changing the type and proportion of isocyanates and prepolymers, it is expected to be practically applied in biomedical fields and daily life. Related Articles | Metrics

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Wear resistance and hardness of dental prosthetics materials versus native teeth Chen Shuang, Li Guo-qiang 2011, 15 (3):  511-514.  doi: 10.3969/j.issn.1673-8225.2011.03.032 Abstract ( 370 )   PDF (686KB) ( 630 )   Save BACKGROUND: There are frictions between native tooth and dental prosthetics materials. In order to protect the native tooth from wear out and lengthen the in-service life of dental prosthetic restorations simultaneously, it is necessary to understand tribological characteristics between native tooth and dental prosthetics materials. Accordingly, we can select the matching prosthetics materials. OBJECTIVE: To compare wear resistance and hardness of native teeth and dental prosthetics materials. METHODS: A computer searched of PubMed database (http://www.ncbi.nlm.nih.gov/PubMed) and Wanfang database (http://www.wanfangdata.com.cn) from 2000 to 2010 was performed to retrieve articles about tribological characteristics between native tooth and dental prosthetics materials, with key words of “enamel, dental restorative material, zirconia, wear resistance, hardness” in English and in Chinese. A total of 46 articles were screened out, and 30 ones according to the inclusive criteria were involved for further summary. RESULTS AND CONCLUSION: The dental enamel has excellent tribology performance and wear resistance, but the dentin has poor wear resistance, once the dentin of native teeth exposes in wearing process, the abrasion will speed up. Therefore, it is extremely necessary to chose ideal dental prosthetic restoration materials which have similar wearing characteristic with native teeth. The abradability of dental enamel is fantastically higher than composite resin. The abradability of composite resin itself is not very good, so it wears little to the native tooth. The physical performance of new type composite resin is raising up unceasingly, and the abradability of some composite resins is approaching to the enamel. The specimens made from Bayer tooth, thermosetting plastic, copper base alloy, titanium and its alloy are thus idea prosthetic materials. Zirconium ceramics belong to biological inertia ceramics, and have good biocompatibility, strong intensity and tenacity. It is a new type dental prosthetic material. Related Articles | Metrics

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Factors affecting the function of drug-loaded microspheres in artificial bone Li Chao, Fang Tao-lin, Dong Jian 2011, 15 (3):  515-518.  doi: 10.3969/j.issn.1673-8225.2011.03.033 Abstract ( 268 )   PDF (557KB) ( 317 )   Save BACKGROUND: As carriers of growth factors or genes, microspheres made with artificial biodegradable materials have been used in bone tissue engineering by many researchers. But the effect of these microspheres on bone defects repair is different, and depends on many factors. OBJECTIVE: To discuss the factors that affect the function of drug loaded microspheres in bone defect repair, and to lay a foundation for further effective application of drug loaded microspheres.   METHODS: A computer-based online search of PubMed (1999-01/2010-04) and CNKI (1999-01/2010-04) was performed for related articles with the keywords “gene or growth factor, nanosphere or microsphere, bone”. Thirty studies about application of growth factors- or genes-loaded microspheres were included. RESULTS AND CONCLUSION: The effect of the drug loaded microspheres is closely related to their material and diameter, surface modification, types of drug loaded and the method of these microspheres combine with artificial bone scaffold. But these factors have not been researched thoroughly and controlled well. Controlling these factors well and ensuring the effective application of drug loaded microspheres in bone tissue engineering need more research from all aspects. Related Articles | Metrics

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Clinical application of bone cement injection in spinal surgery Yang Zhi-xian, Peng Xiao-zhong 2011, 15 (3):  519-522.  doi: 10.3969/j.issn.1673-8225.2011.03.034 Abstract ( 387 )   PDF (729KB) ( 401 )   Save BACKGROUND: As a new technology in the field of minimally invasive spinal surgery, percutaneous vertebroplasty (PVP) has aroused wide concern. The application of bone cement injection has got great development in senilely clinical osteoporotic vertebral compression fracture (OVCF), stable fracture spinal, spinal tumor, and carcinoid tumor. OBJECTIVE: To summarize the clinical application and advances of bone cement injection in spinal surgery both at home and abroad. METHODS: Within the database CNKI and Pubmed (http://www. ncbi.nlm. nih.gov/sites/entrez) to search the articles about vertebroplasty (2005-01/2009-12), with “vertebroplasty” or “PVP” as key words. Within the 748 articles as results, articles on “PKP”, “SKY”, “compressed fracture” and “spinal tumor” were retrieved, again. Fity-nine articles about spinal bone cement injection were selected, and lately published or on authoritative magazines were chosen if in the same field. Finally, 26 typical  articels about spinal bone cement injection were selected after browsing the whole passage according the standards, together with another two from OVID ONLINE.   RESULTS AND CONCLUSION: Percutaneous bone cement injection shows remarkable effects on senile OVCF, stable spinal fracture in the young and middle aged, spine metastatic tumour, or pain induced by spine carcinoid tumour. With the characteristics as simple operation, short duration of surgery, and fewer serious complications, it is widely accepted by most patients and professional medical staff. As the research and development of new bone cement technology, bone cement injection will be more widely applied in spinal surgery. Related Articles | Metrics

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Application of temporary abdominal closure materials and techniques in abdominal wall defects Shao Jian-chuan, Han Yan 2011, 15 (3):  523-526.  doi: 10.3969/j.issn.1673-8225.2011.03.035 Abstract ( 232 )   PDF (588KB) ( 561 )   Save BACKGROUND: The treatment for abdominal defects is one of the problems of surgical treatment, especially primary closure is really a challenge to surgeons. As the surgical concept of defect control develops, and many technique and materials of temporary abdominal closure appear, some effective treatments for abdominal defects are emerged to solve this problem. OBJECTIVE: To review the current status of temporary abdominal closure materials and techniques in abdominal wall defects. METHODS: A computer-based online search of PubMed database (1986/2010) and CNKI (2005/2010) was retrieved with key words of “abdomen, abdominal wall, abdominal injuries/surgery, laparotomy, temporary abdominal closure, patch, vacuum-assisted closure, wound healing” in English and in Chinese. A total of 278 literatures were collected through computer retrieval, excluding irrelevant, obsolete, repeated and similar researches, finally 31 standard literatures were included. RESULTS AND CONCLUSION: The application of temporary abdominal closure is an important treatment of abdominal wall defects, it can improve the prognosis and increase the cure rate. There are various materials and techniques of temporary abdominal closure with advantages and disadvantages, and each one has its own indications. The use of specific material and operative technique should base on the principles and specific conditions of patients. Related Articles | Metrics

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Clinical application of biodegradable polydioxanone Qu Le, Cao Jiang, Huang Xin-miao 2011, 15 (3):  527-530.  doi: 10.3969/j.issn.1673-8225.2011.03.036 Abstract ( 574 )   PDF (676KB) ( 505 )   Save BACKGROUND: Recent studies indicate that polydioxanone (PDO) has excellent biodegradability, bioabsorbability and biocompatibility, and it is widely used as tissue repair materials and scaffold materials in medical fields. However, the immunological reaction and mechanism evaluations in vivo need further investigation, so as to better understand the role of these materials in immune system. OBJECTIVE: To summarize and analyze the degradation characteristics of PDO and its clinical application progress. METHODS: A computer-based search of PubMed database and CNKI database (2000-01/2010-06) was performed using “polydioxanone, absorbable” in English and “polydioxanone” in Chinese as the key words. A total of 176 articles on the PDO clinical application were selected, including 39 Chinese and 137 English. The earlier published, repeated and similar studies were excluded, finally 25 articles were included in accordance with the criteria. RESULTS AND CONCLUSION: PDO, one kind of aliphatic polyesters, has excellent biodegradability, bioabsorbability and biocompatibility, and it also has good flexibility. So PDO is the ideal material for surgical suture. It is also used for laminates, tissue repair, electrospun cardiovascular graft and so on. PDO has a wide application prospect in clinical application. Related Articles | Metrics

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Clinical chitosan prevention against postoperative intestinal adhesions Chen Yan, Xing Yu-jian, Wu Qian-teng 2011, 15 (3):  531-534.  doi: 10.3969/j.issn.1673-8225.2011.03.037 Abstract ( 375 )   PDF (704KB) ( 460 )   Save OBJECTIVE: To explore the role of chitosan for the prevention of postoperative intestinal adhesion. METHODS: A computer-based online search of CNKI from 1989 to 2009 was conducted, three authors participated in the literature screening, data acquisition and quality evaluation. The intestinal ventilation time and the incidence of intestinal adhesion after surgery in chitosan-treated group and control group were compared in subjects met the inclusive criteria. RESULTS: Totally fifteen studies were in accordance with the inclusive criteria. Results showed that, the intestinal ventilation time and the incidence of intestinal adhesion rate post-operation in chitosan-treated group was significantly lower than routine treatment group. CONCLUSION: Chitosan can significantly reduce the incidence of intestinal adhesion rates and shorten intestinal ventilation time, chitosan can be well prevent intestine from adhesion after operation and promote gastrointestinal functional recovery. Related Articles | Metrics

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Application of biological bandage and dressing in wound healing Liu Jing 2011, 15 (3):  535-538.  doi: 10.3969/j.issn.1673-8225.2011.03.038 Abstract ( 270 )   PDF (708KB) ( 485 )   Save BACKGROUND: Medical dressings as covering of the wound can replace damaged skin and play a temporary barrier function in the process of wound healing, and avoid or control wound infection to provide a conductive environment for wound healing. How to fixed quickly, stop bleeding effectively, and reduce or prevent the adverse effect of injured limb blood circulation after hemostasis, the acceleration of wound healing and the reduction of pain is an urgent problem of trauma critical care medicine. OBJECTIVE: To introduce the application status and research progress of medical biological dressings in the field of wound healing, and reveal its development prospect to provide theoretical basis for the application of medical biological dressings in the progress of wound healing. METHODS: The articles concerning medical biological dressings were retrieved in CNKI database and PubMed database from January 1998 to December 2008, using the key words of “medical dressing, biological material, chitosan, hydrogel, tissue engineering” in Chinese or “medical dressing, biological material, chitosan, hydrogel, tissue engineering” in English in the title and abstract. The content of articles related with wound healing and literatures recently published or published in authoritative magazines from the same field were selected. Totally 146 literatures were primarily selected (Chinese 107, English 39), according to inclusion criteria, 38 documents of which were involved for summarization. RESULTS AND CONCLUSION: The medical dressings of the current clinical use and research were divided into natural material and synthetic macromolecule, inorganic material and composite according to the materials. Moreover, the problems of dressing products in the quality control were discussed, the further direction of dressing products was prospected, and a theoretical basis for research and development of dressing products were provided. Related Articles | Metrics

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Performance evaluation of tissue engineered tendon reconstructed using different scaffolds Yang Hong-wu, Han Chao, Chi Qiang, Zhao Yun-na 2011, 15 (3):  539-542.  doi: 10.3969/j.issn.1673-8225.2011.03.039 Abstract ( 371 )   PDF (714KB) ( 345 )   Save OBJECTIVE: To summarize the main tissue engineered scaffold materials for tendon injury repair and research progress. METHODS: A computer-based online search of CNKI database from January 1902 to October 2010 was performed by the first author to retrieve studies on the biomaterials used for tissue engineered tendon scaffolds, with key words of “tendon reconstruction, biological materials, artificial tendons, tissue engineering, scaffold materials” in Chinese. Duplicated research, reviews or Meta analysis were excluded, finally 18 articles were selected into the evaluation. RESULTS: The natural biomaterials include silk, small intestinal submucosa, collagen, derivative tendon scaffold and so on, normal three-dimensional network structure of the tissue is retained, tissue compatibility is good, but mechanical properties are poor and degradation speed is fast. Synthetic polymer materials primarily consist of polylactic acid and polyglycolic acid, polylactic acid-polyglycolic acid copolymer, polyphosphoric acid calcium fibers and so on, but they are low hydrophilic and poor performance of cell adhesion. CONCLUSION: The natural and synthetic polymer scaffolds for tissue engineering has its own advantages and disadvantages, most of them are still in the research stage and have not been applied to clinical practice, so improving the performance of scaffolds is one of the main directions of current research. Related Articles | Metrics

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Tissue engineering technology and biomaterials for repair of sports articular cartilage injury Ma Jin-yu, Xue Yuan, Yang Hong-wu 2011, 15 (3):  543-546.  doi: 10.3969/j.issn.1673-8225.2011.03.040 Abstract ( 219 )   PDF (523KB) ( 346 )   Save OBJECTIVE: To summarize the application characteristics of tissue engineering technology and biomaterials in preventing sports articular cartilage injury. METHODS: A computer-based online search of Pubmed database (http://www.ncbi.nlm.nih.gov/PubMed) and VIP database (http://www.cqvip.com/) from January 1993 to October 2010 was performed for related articles, using “articular cartilage, tissue engineering technology, biomaterials” for the Chinese key words and “tissue engineering, articular cartilage, scaffold material” for the English key words, duplicated research or Meta analysis were eliminated. Twenty-three papers mainly discuss seed cells, scaffolds, cytokines and their properties in the repair of sports articular cartilage injury. RESULTS: Totally 104 studies were screened out by computer search, according to inclusion and exclusion criteria, studies regarding the seed cells and bio-scaffolds for cartilage tissue engineering, as well as cytokines for tissue engineering were summarized and analyzed. Seed cells are the primary factor restricting clinical application of tissue engineered cartilage, the common seed cells include cartilage cells, bone marrow stromal stem cells and embryonic stem cells; bio-scaffold materials includes natural materials and synthetic biodegradable polymers; the growth factors for cartilage tissue engineering include transforming growth factor, bone morphogenetic protein, fibroblast growth factor, insulin-like growth factor and so on. CONCLUSION: So far, there is no ideal materials for the seed cells and scaffold materials of engineered cartilage, as well as culture environment, the focus of future research is a kind of tissue engineered articular cartilage with good performance. However, many studies are still in the experimental stage, and some problems need to be solved, especially after tissue engineering scaffolds are implanted, whether the material degradation is synchronized with cell functioning, thus altering genetic materials, gene expression or gene mutation, their clinical application requires relevant scholars and experts to constantly practice and explore. Related Articles | Metrics

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Surface modified biomaterials for repairing acute exercise-induced bone damage Huang Yu-chun 2011, 15 (3):  547-550.  doi: 10.3969/j.issn.1673-8225.2011.03.041 Abstract ( 186 )   PDF (521KB) ( 262 )   Save BACKGROUND: The key research of bone tissue engineering scaffolds is selecting the appropriate materials for surface modification, targeting to the surface modification of matrix scaffold materials, improving the cell adhesion on the surface of materials, and promoting cell proliferation. OBJECTIVE: To overview application of bone tissue engineering scaffold materials and scaffold surface modification materials, as well as the modification method or means. METHODS: A computer-based online search of PubMed database and Wanfang database from 1995 to 2010 was performed by the first author for articles related to use of tissue engineering scaffolds and surface modification. RESULTS AND CONCLUSION: The roles of osteoblasts and scaffolds depend on the material surface properties, local morphology, surface energy or chemical energy, etc. These surface characteristics determine how to adsorb to the material surface, cell positioning and cell functional behavior. Therefore, the complexity of biomaterials and cell-biomaterial surface interactions determine the importance of surface modification of biological scaffolds. Ideal surface modification should take into account the surface topology, specific identification, hydrophilic and hydrophobic balance, protein adsorption, thus obtaining functionalized new tissue. Currently, the most widely used material for surface modification is collagen I, future research will focus on complementary roles of a variety of composite materials for surface modification, as well as gene therapy and the development of nano-materials, becomes a hot issue in the field of bone tissue engineering study. Related Articles | Metrics

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Role of tissue engineered tendon in tendon repair Li Rong 2011, 15 (3):  551-554.  doi: 10.3969/j.issn.1673-8225.2011.03.042 Abstract ( 263 )   PDF (510KB) ( 388 )   Save OBJECTIVE: To review the research progress of tendon tissue engineering in the process of tendon repair. METHODS: A computer-based search of PubMed database and VIP database from January 1993 to October 2009 was performed for articles regarding the tendon tissue engineering, bio-mechanical analysis of tendon scaffolds, biomaterials’ application in tendon tissue engineering and tissue engineering technology in the clinical application of tendon defect repair. English key words are “tendon transplantation, tissue engineering, biological material, cell stent”, Chinese key words are “tendon transplantation, tissue engineering, biomaterials, cell scaffold”. A total of 132 literatures were screened out. RESULTS: At present, the tendon tissue engineering research has achieved remarkable results, but there are still some problems for clinical practice and mass production. Many issues need to be further studied and solved prior to tissue engineering truly becomes a treatment of tendon defect and functional reconstruction, such as the best source of seed cells, the ideal scaffold material, the best culture conditions and detection methods of implantation in vivo. CONCLUSION: Truly realizing the replacement of human tissues and organs with the in vitro prefabricated living implant, still faces many challenges. Related Articles | Metrics

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Effects and material properties of absorbable suture on the repair of sports ligament injury Geng Hai-yan 2011, 15 (3):  555-558.  doi: 10.3969/j.issn.1673-8225.2011.03.043 Abstract ( 228 )   PDF (672KB) ( 436 )   Save BACKGROUND: The advancement and development of suture technique provide a guarantee for treatment of tendon and ligament tissue tear or fracture, the use of absorbable suture materials can avoid the treatment risk by using non-absorbable suture material to a greater extent, and are generally well received by doctors and patients. OBJECTIVE: To analyze the material can be absorbable suture material characteristics, to explore ligament injury rehabilitation in the clinical value of the project. METHODS: PubMed database and Wanfang database from 1990 to 2010 were searched by the first author for articles related to soft tissue suture treatment, materials science characteristics, biocompatibility and its application effect. RESULTS AND CONCLUSION: Absorbable suture can degrade in vivo into soluble products, thus reducing the suffering of patients during secondary surgery and minimize the scar formation at suture site in patients, it is more and more popular in both doctors and patients, at present different materials of absorbable suture emerge, thus meeting the needs to a certain extent. Related Articles | Metrics

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Serum inflammatory factor expression and coronary restenosis in patients following coronary stent implantation Zhang Dong-hui 2011, 15 (3):  559-562.  doi: 10.3969/j.issn.1673-8225.2011.03.044 Abstract ( 379 )   PDF (621KB) ( 303 )   Save OBJECTIVE: To summarize the influence of serum inflammatory factors on the restenosis after coronary artery stent implantation. METHODS: Using “coronary artery disease, coronary artery stent implantation, inflammation mediated, scaffold” as the key words, Chinese Journal Full-text database and Medline database were searched from 2001 to 2010. The involved subjects were coronary atherosclerotic heart disease patients who require stenting; confirmed by coronary angiography, these patients were diagnosed as coronary heart disease; there was no limitation in the age, gender, race and region of the patients, and they agreed to coronary stent implantation; detection index was the expression of inflammatory factors. Cases with infectious diseases, bleeding disorders, leukemia, severe liver disease, severe renal insufficiency and cancer are ruled out. A total of 23 literatures were chiefly investigated. RESULTS: After stent implantation, sCD40L concentration increases along with serum soluble intercellular adhesion molecule-1 concentrations increase. Serum soluble intercellular adhesion molecule-1 and matrix metalloproteinase-9 levels were elevated following stent implantation, and the expressions of adhesion factor serum soluble intercellular adhesion molecule-1 and matrix metalloproteinase 9 were up-regulated; serum interleukin 18 levels and C-reactive protein levels were significantly influenced. CONCLUSION: In the process of stent implantation, the balloon dilation, stenting and a series of extruded plaque factors contribute to the release of inflammatory factors, increase serum levels of inflammatory factors. Coronary vascular remodeling and reperfusion after vascular injury also promote the increase, and the raising range is associated with coronary artery disease. Related Articles | Metrics

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Application of self-etching agent in orthodontic bracket bonding of oral prosthodontics He Jian-ling, Qing An-rong, Chen Yi 2011, 15 (3):  563-566.  doi: 10.3969/j.issn.1673-8225.2011.03.045 Abstract ( 322 )   PDF (582KB) ( 393 )   Save OBJECTIVE: To summarize the research progress of orthodontic bracket bonding with self-etching agent in recent years. METHODS: A computer-based retrieval of Wanfang database was conducted for articles about orthodontic bracket bonding with self-etching agent, retrieval time is from September 2000 to August 2010. Key words are “self-etching agent; bracket; shear strength”. Inclusion criteria: (1) directly targeted and highly relevant literatures. (2) Repetitive researches were excluded. All data were preliminarily screened, and citations after each article were checked. RESULTS: Totally 20 literatures met the inclusive criteria, compared with traditional adhesive enamel, self-etching adhesive agent has a similar shear strength of orthodontic bracket. There was no significant difference between two methods in the enamel adhesive residual after the bracket removed. CONCLUSION: Compared with the traditional enamel etching adhesive, the self-etching agent has a reliable shear strength and low remnant index of the adhesive agent, thus it can meet the need for orthodontic bracket bonding. Related Articles | Metrics

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Release of insulin and C peptide associated with cell concentration in alginate-polylysine- alginate microcapsules Wang Ya-guang, Ma Yun-sheng, Mu Chang-zheng, Cai Hong-yu, Wang Zheng 2011, 15 (3):  567-570.  doi: 10.3969/j.issn.1673-8225.2011.03.046 Abstract ( 326 )   PDF (659KB) ( 366 )   Save BACKGROUND: Microencapsulation has been widely used in various experimental studies, microencapsulated stem cell therapy for diabetic mellitus has become a hot issue, but the relationship between the wrapped cell concentration and the insulin release becomes one of the problems required to be solved. OBJECTIVE: To investigate the influence to the release of insulin and C peptide by the density of the insulin-producing cells (IPCs) encapsulated by alginate-polylysine-alginate microcapsules. METHODS: The extracts of rat pancreatic injury were prepared, and mouse bone marrow mesenchymal stem cells were induced to differentiate into IPCs. Immunofluorescence and dithizone staining were used to identify the expression of insulin in the induced cells. IPCs were prepared into cell suspension at 1×107/L, 5×104/L, 1×108/L, 5×108/L, 1×109/L, 5×109/L, and then prepared microcapsules by gas blowing spray. Cell viability was detected with 6-carboxyl fluorescein diacetate. Glucose was used to stimulate the cells in microcapsules and to examine the release of insulin and C peptide. RESULTS AND CONCLUSION: After extracts of rat pancreatic injury were induced, the immunofluorescence and dithizone staining have identified the insulin expression in IPCs; IPCs microcapsule was approximately 400 um diameter with uniform size, 6-carboxyl fluorescein diacetate detected that cell vitality was good. Glucose was used to stimulate the microcapsules at different cell densities, results found that the secretion of insulin and C peptide reach a peak at cell density of 1×108/L. Related Articles | Metrics