Table of Content

15 October 2010, Volume 14 Issue 42 Previous Issue    Next Issue

For Selected:

Download Citations EndNote Reference Manager ProCite BibTeX RefWorks

Toggle Thumbnails

Select

Hydroxyapatite/tricalcium phosphate combined with bone morphogenetic protein and basic fibroblast growth factor repairs bone defects in rabbits Zheng Jun, Tang Wei-zhong, Qi Xin-sheng 2010, 14 (42):  7791-7794.  doi: 10.3969/j.issn.1673-8225.2010.42.001 Abstract ( 269 )   PDF (552KB) ( 456 )   Save BACKGROUND: Cytokines can initialize, promote and maintain cartilage and bone formation, but require a suitable carrier to exert biological activity. OBJECTIVE: To investigate the repaired effects of bone defected by the compound of hydroxyapatite/tricalcium phosphate (1:1, HA/TCP) combined with bone morphogenetic protein (BMP) and basic fibroblast growth factor (bFGF). METHODS: A 4 mm × 4 mm × 12 mm bone defect was produced in both thighbone of 27 experimental rabbits, which were randomly divided into three groups, BMP + bFGF + HA/TCP, BMP + HA/TCP, HA/TCP groups. The repair of bone defects in each group was investigated by means of hematoxylin-eosin staining, X-ray examination, and computer image analysis at 4, 8, 12 weeks after operation. RESULTS AND CONCLUSION: BMP + bFGF + HA/TCP group and BMP + HA/TCP group were superior to HA/TCP group regarding the cartilage induction, trabecular bone formation and bone defects repair. In addition, BMP + bFGF + HA/TCP group was better than BMP + HA/TCP group. At 8 weeks after operation, woven bone trabecular gradually developed into mature lamellar bone and pulp cavity, bone defects were almost repaired. At 12 weeks, bone defects were completely repaired. Results indicated that the compound of HA/TCP, BMP and bFGF possesses strong osteogenesis potential and the ability of rebuilding bone defect. BMP combined with bFGF can apparently promote new bone formation. The porous HA/TCP is a good controlled-release scaffold material and can absorb cytokines, its degradation and absorption are interacted with new bone formation. Related Articles | Metrics

Select

Repair of articular osteochondral defects with bone marrow stromal stem cells/nano-beta-tricalcium phosphate/collagen I and II composite Chen Zhu-sheng, Lü Yu-ming, Zhang Bing 2010, 14 (42):  7797-7801.  doi: 10.3969/j.issn.1673-8225.2010.42.003 Abstract ( 328 )   PDF (583KB) ( 565 )   Save BACKGROUND: Articular cartilage injury repair is mainly faced with the great difference in the structure and physiological functions between regenerated cartilage and normal cartilage, far away from normal physiological needs, there are many current repair methods, but the results are not satisfactory. OBJECTIVE: To study the feasibility of repairing articular osteochondral defects in canines using nano-β-tricalcium phosphate (TCP)/collagen I and II composite loaded with bone marrow stromal stem cells (BMSCs). METHODS: Ten 12-month-old hybrid canines were randomly divided into experimental group and defect control group, and BMSCs were sterilely obtained from iliac crest in each animal. Primary culture and subcultures were done. The third passage of BMSCs was digested and collected, cell density was adjusted to 2.0 × 106 L-1, the cells were co-cultured with nano- β-TCP/ colI/colII for 24 hours, then nano β-TCP/colI/colII/BMSCs composites were prepared. Articular osteochondral defects were made in canine right knees, those in experimental group were treated with nano β-TCP/colI/colII/BMSCs composites, while those in control group were left untreated. RESULTS AND CONCLUSION: At 12 weeks, the defects in the experimental group were filled with white translucent tissues, which appeared smooth, soft and slightly protruded, chondrocytes distributed uniformly but aligned disorderly. At 24 weeks, the defects in the experimental group were filled with white translucent cartilage tissue, which appeared smooth and tenacious. The color and the luster were similar to that of the normal cartilage, and was ill-demarcated from the surrounding normal cartilage. The cells on the surface paralleled to joint surface. The cells in the deep layer arranged disorderly. In many areas, the cells clustered together. The matrix was extensively metachromatic and the new cartilage finely integrated with normal cartilage. In the control group, the defects showed little repair response macroscopically, only some white fibrous tissue can be seen at the bottom. BMSCs are ideal seed cells for repairing articular cartilage defects. Nano-β-TCP/colI/colII is gradually degraded and absorbed while new cartilage tissues form. It can be used as a suitable scaffold material for tissue engineered repair of articular cartilage defects. Related Articles | Metrics

Select

Immunological analysis of improved heterogeneous deproteinized bone for bone defects repair Jian Yue-kui, Luo Yang, Tian Xiao-bin, Li Bo, Peng Zhi, Ding Yi, Luo Chun-shan, Zhao Wei-feng, Yang Zhen 2010, 14 (42):  7802-7806.  doi: 10.3969/j.issn.1673-8225.2010.42.004 Abstract ( 358 )   PDF (385KB) ( 421 )   Save BACKGROUND: The immunogenicity of heterogeneous bone remains unsolved in the choice of scaffold materials. OBJECTIVE: To observe the immunological properties of heterogeneous deproteinized bone prepared by modified method. METHODS: Eighteen goats of SPF grade were randomly divided into three groups, normal bone group without osteotomy, autologous bone group and heterogeneous deproteinized bone group were produced a 20% length of periosteum and bone defects in right tibial middle and inferior segments. Autologous bone group was implanted with autologous bone; in heterogeneous deproteinized bone group, goat autologous bone marrow mesenchymal stem cells were collected and adjusted into a density of 1×109/L, 2 mL cell suspension was incubated onto porcine deproteinized bone modified with porcine femoral bone, adding recombinant human bone morphogenetic protein 2, followed by semi-ring trough external fixation. The immunological detection of CD4+ and CD8+ T lymphocytes, serum antibodies IgG was performed using flow cytometry, bone defects repair was determined with dual-energy X-ray measurement. RESULTS AND CONCLUSION: After heterogeneous deproteinized bone was implanted 3, 7, 14, 28 days, the levels of CD4+ and CD8+ T lymphocytes in peripheral blood were normal (P > 0.05), serum IgG antibody level was slightly higher than the autologous bone group (P > 0.05); at 24 weeks after implantation, bone mineral density and bone mineral content were similar to autologous bone group (P > 0.05), showed high-density calcification between the two ends of bone defect area. The pressure resistance and ultimate pressure, resistance to bending loads and limit load, torsion torque and ultimate torque were similar in three groups (P > 0.05). At 24 weeks after implantation, there was no significant difference in osteogenic potential between autologous bone group and heterogeneous deproteinized bone group (P > 0.05). The improved heterogeneous deproteinized bone does not cause significant cellular and humoral immune response, has good biocompatibility, does not affect the osteogenesis of autologous bone marrow mesenchymal stem cells, biomechanical properties of new bone are equal to autologous bone. Related Articles | Metrics

Select

Bone marrow mesenchymal stem cells transfected by human bone morphogenetic protein-2 and bioactive glass ceramics composite material for repair of skull defects Zheng De-yu, Yang Yi-yong, Zhao Kai, Zheng Shi-jie, Zhang Yu-hua, Qin Shu-jian 2010, 14 (42):  7807-7810.  doi: 10.3969/j.issn.1673-8225.2010.42.005 Abstract ( 232 )   PDF (331KB) ( 358 )   Save BACKGROUND: The current studies have reported in vitro cultured bone marrow mesenchymal cells combined with scaffolds to repair the bone defects. However, the bone formation in situ remains un-satisfactory due to lack of bone growth factor in such composite. OBJECTIVE: To investigate the in situ osteogenic effect of artificial bony graft, formed by bone marrow mesenchymal stem cells (BMSCs) modified by human bone morphogenetic protein-2 (hBMP-2) and bioactive glass ceramics (BGC) for repairing skull defects of rabbits. METHODS: The BMSCs transfected hBMP-2 gene were cryoopreserved and resuscitated, then composited with BGC to prepare artificial bony graft. Rabbits skull defect models, created on the both parietal bones, were filled with the artificial bony graft, as the experimental group. While those treated by blank plasmid-transfected BMSCs + BGC and simple BMSCs + BGC, as the control groups. Blank control group was also set. The bone defects were observed by gross observation, X-ray, immunohistochemical and biochemical detections in the 4th, 8th, 12th weeks after operation respectively. RESULTS AND CONCLUSION: At four weeks after BMSCs transfected with hBMP-2 and BGC composite materials were transplanted into the skull defect, the interspace of artificial bone and bone defect were mainly filled by high density shadow in the experiment group, at 12 weeks, the space were completely filled by high density shadow. The great part of bony trabeculae were connected each other at 8 weeks, and bony trabeculae become thicker and formed as a network and new marrow regenerated at 12 weeks. The outcomes of biochemistry were coincided with the outcome of immunohistochemistry. The bone formation and osteogenesis activity were markedly better than those in control groups. The artificial bony graft formed by BMSCs transfected by hBMP-2 and BGC may satisfy the requirement of bone tissue engineering and has good effects for accelerating the bone defects healing. Related Articles | Metrics

Select

Preparation and characteristics of chitosan-collagen compound bone and cartilage defect scaffolds Wang Jiu-hui, Wei Dong-xing, Zhang Zhen　 2010, 14 (42):  7811-7814.  doi: 10.3969/j.issn.1673-8225.2010.42.006 Abstract ( 212 )   PDF (393KB) ( 354 )   Save BACKGROUND: Bone tissue engineering scaffolds develops from autologous bone, cartilage materials to bioactive ceramics, even organic material collagen and other extracellular matrix, their biocompatibility and performance become more and more excellent, close to in vivo conditions. However these materials need to improve anti-compression and strength. OBJECTIVE: To prepare biological scaffolds by adjusting the proportion of collagen and chitosan, to test biological characteristics and to offer a graft for bone and cartilage defect. METHODS: Chitosan and collagen protein were melted by different ratios, then the materials were freeze-dried after UV cross-linking to prepare scaffolds by twice freeze-dry. The porosity, degradation rate, swelling ratio of the scaffolds at different proportions were determined. The particle size and distribution were observed by scanning electron microscope. RESULTS AND CONCLUSION: The prepared scaffold was sponge and porous. The aperture of the scaffold was negatively related with the collagen content. The collagen had less impact on the overall porosity with the increased ratio of collagen. The swelling rate can reach about 80%, swelling degree of the scaffold was reduced with the increasing proportion of collagen. The toughness degree and degradation rate increased with the collagen ratio up. The higher chitosan content, the slower degradation rate. Adjusting collagen and chitosan ratio could make the scaffolds as a substitute for the bone and cartilage defect transplantation. Related Articles | Metrics

Select

Effect of rapamycin-poly(lactide-acid)/magnetic microsphere composite materials on the proliferation of vascular smooth muscle cells Lü An-lin, Xing Yu-jie, Wang Li, Yan Xue-bo, Zhao Wei 2010, 14 (42):  7815-7818.  doi: 10.3969/j.issn.1673-8225.2010.42.007 Abstract ( 313 )   PDF (298KB) ( 376 )   Save BACKGROUND: Polylactic acid is a commonly used material for vascular stent coating at present, with advantages of biodegradation, plasticity, low antigenicity and good compatibility. Magnetized metal bare stent may significantly reduce the thrombus and restenosis. OBJECTIVE: To analyze the cell biocompatibility of a new stent coating composite material, rapamycin-polylactide nano-magnetic microspheres, and investigate the influence on vascular smooth muscle cells proliferation. METHODS: Small patches of composite material were made of rapamycin-polylactide nano-magnetic microspheres by dispersion polymerization under standard conditions, then were co-cultured with 3-5 passages of rat aortic smooth muscle cells for 7 days, MTT assay was applied to determine the growth and proliferation of smooth muscle cells. RESULTS AND CONCLUSION: Poly-lactic acid composite membrane of different magnetic microspheres concentrations have different degrees of inhibition on the smooth muscle cell proliferation (P < 0.05). There was no significant difference in the inhibition effect between rapamycin-polylactide nano-magnetic composite microspheres and rapamycin alone (P > 0.05). But the inhibition on the smooth muscle cell proliferation was stronger than single magnetic microspheres of polylactic acid composite membrane (P < 0.05). Composite materials of rapamycin-polylactide nano-magnetic microspheres cam significantly inhibit proliferation of vascular smooth muscle cells, also have good cell biocompatibility. References | Related Articles | Metrics

Select

Laryngeal defects repair using acellular dermal matrix and Ni-Ti alloy stent in a canine model Zeng Bin, Chen Liang-si, Li Xiang, Chen Guo-ping, Peng Jie-ren 2010, 14 (42):  7819-7823.  doi: 10.3969/j.issn.1673-8225.2010.42.008 Abstract ( 378 )   PDF (347KB) ( 489 )   Save BACKGROUND: Ni-Ti alloy stent can be prepared into thyroid cartilage V-shape, and effectively repair the spatial three-dimensional structure, ensure the maximum ventilation throat and vocal function recovery. OBJECTIVE: To investigate the feasibility of applying acellular dermal matrix (ADM) and Ni-Ti alloy stent to repair laryngeal impairment in canine model.  METHODS: Subtotal laryngectomy was performed in six healthy adult hybrid canines, which were divided into two groups with 3 dogs in each group. The ADM and Ni-Ti alloy stent were used to repair laryngeal skeleton of the canine in experiment group. In the control group, only Ni-Ti alloy stent was used to repair the laryngeal impairment. Animals were performed X-ray and endoscopic examination in 1 and 6 months after surgery, and were sacrificed at 6 months. The specimens were taken out for gross observation and histological examination. RESULTS AND CONCLUSION: The result of X-ray showed the Ni-Ti alloy stent was firmly attached to the reduced thyroid cartilage, without migration or extrusion. Gross anatomy examination revealed good repair effect of laryngeal mucosa in experimental group, except a small amount of scar formed in one case, the remaining 2 cases had no scar formation, with smooth throat and without laryngostenosis, postoperative breathing and swallowing function recovered well. In the control group, stent surface granulation and scar tissue proliferated in three cases, 1 patient of which died of dyspnea at 63 days after operation. Histological examination showed most of the epithelium in the experimental group was covered with stratified squamous epithelium, vascular tissue and some lymphocytes were seen in stroma. In the control group, granulation tissue and fibroplasia were evident, without the stratified squamous epithelium covered, there were massive lymphocytes and plasma cells in stroma. Ni-Ti alloy stent combined with ADM could effectively repair the laryngeal impairment. The method provides adequate support and reduces formation of granulation and scars. Related Articles | Metrics

Select

Preparation of orthogonal optimized paclitaxel-loaded polylactide-co-glycolide nanoparticles Xue Jing, Huang Yue-shan 2010, 14 (42):  7824-7828.  doi: 10.3969/j.issn.1673-8225.2010.42.009 Abstract ( 367 )   PDF (387KB) ( 406 )   Save BACKGROUND: Polylactide-co-glycolide (PLGA) nanoparticles or nano-preparation of biodegradable microspheres for sustained release or targeted delivery system have been studied for almost 30 years, considered as a hot spot of research. The system can control the particle size, delay drug degradation, prolong drug release time, conduct targeted release, reduce drug toxicity and irritation. OBJECTIVE: To explore the preparation method of the drug-loaded nanoparticles on particle size, encapsulation efficiency and other effects, and to determine the optimal preparation conditions using paclitaxel as a model drug and PLGA as the coating material. METHODS: PLGA nanoparticles were prepared using emulsion-solvent evaporation technique. The particle size of nanoparticles was measured, and the encapsulation efficiency and drug loading of the nanoparticles were calculated. The preparation techniques of nanoparticles were optimized by orthogonal method. RESULTS AND CONCLUSION: Through orthogonal test, the preparation techniques of nanoparticles were optimized. The optimization parameters are 15 minutes ultrasonic emulsification, 1% concentration of emulsifier, organic to water ratio of 1: 25, temperature 25 ℃. Under these conditions, the prepared nanoparticles size was 217.6 nm, drug loading was 1.79%, encapsulation efficiency was 85%. The preparation process is simple, stable and optimized. The paclitaxel-PLGA appropriate nanoparticles can be prepared at a high entrapment efficiency and suitable particle size. Related Articles | Metrics

Select

Preparation and cytotoxicity of SiO2/Nd-Fe-B core-shelled nanoparticles applied to surgical anastomosis Xie Zhan-tao, Li Jian-hui, Qian Jun-min, Huang Shi, Wan Zhen, Yu Liang, Liu Chang, Lü Yi　 2010, 14 (42):  7829-7834.  doi: 10.3969/j.issn.1673-8225.2010.42.010 Abstract ( 333 )   PDF (1065KB) ( 874 )   Save BACKGROUND: Magnetic compression device has acted increasing attention due to its superior performance, however, its retention in vivo would adversely affect the body, and biodegradable magnetic device is expected to solve this problem. OBJECTIVE: To product core-shelled SiO2/Nd-Fe-B nanoparticles which can be applied to surgical anastomosis and to evaluate their cytotoxicity. METHODS: The Nd-Fe-B nanoparticles were produced with high energy ball milling method, surface modification to the Nd-Fe-B nanoparticles was performed with sol-gel method. The cytoxicity was tested using MTT method. The core-shelled SiO2/Nd-Fe-B nanoparticles were co-cultured L929 cells, to observe the distribution of SiO2/Nd-Fe-B nanoparticles in cells and pathology of subcellular organelle, as well as the metabolism of SiO2/Nd-Fe-B nanoparticles in the subculturing cells. RESULTS AND CONCLUSION: The core-shelled SiO2/Nd-Fe-B nanoparticles were successfully produced, the result of MTT test indicated that the cytotoxicity degree of the extract of core-shelled SiO2/Nd-Fe-B nanoparticles was 1, without significant difference of absorbance value with blank control group (P > 0.05). SiO2/Nd-Fe-B nanoparticles could enter the cells though endocytosis, and distributed in the cytoplasm without nucleus, transmission electron microscopy found a slight swelling of mitochondria and expansion of endoplasmic reticulum. Subcultured cells which contained SiO2/Nd-Fe-B nanoparticles found that nanoparticles rapidly reduction during three subcultures. SiO2/Nd-Fe-B nanoparticles can be produced using high energy ball milling combined with sol-gel method. SiO2/Nd-Fe-B nanoparticles have mildly toxicity, and can meet the requirement of the national standard for medical implantation materials. SiO2/Nd-Fe-B nanoparticles could enter the cell through endocytosis, with slight influence on organelle and fast metabolism. Related Articles | Metrics

Select

Histological evaluation of nano-hydroxyapatite/collagen membranes Li Wen-hao, Zhang Min, Liu Jing-ming 2010, 14 (42):  7835-7838.  doi: 10.3969/j.issn.1673-8225.2010.42.011 Abstract ( 337 )   PDF (299KB) ( 404 )   Save BACKGROUND: Early used guided bone regeneration membrane composed of collagen, polylactic acid and other single components has gradually revealed its defects in the efficiency of osteogenesis, while guided bone regeneration membrane composed of collagen, polylactic acid and other absorbable materials as the carriers, in combination with hydroxyapatite, fibroblast growth factor, bone morphogenetic protein, has become a focus of the study. OBJECTIVE: To evaluate the absorption and tissue reaction of nano-hydroxyapatite/collagen (nHAC) membrane for guided bone regeneration. METHODS: Three kinds of guided bone regeneration membranes (nHAC, polylactic acid-polyglycolic acid, collagen) were implanted under the dorsal skin of the rats, which were respectively sacrificed on 10, 20, 30 and 45 days after implantation. Using hematoxylin-eosin staining, the specimens were assessed histologically for the quantify and quality of tissues surrounding the membranes, interface quality and degradation rate, the tissue reaction and degradation of three kinds of membranes were evaluated. RESULTS AND CONCLUSION: There were scattered lymphocytes, but no macrophages in nHAC membrane. The surface of nHAC had some crystal calcium phosphates and the area decreased along with the time prolonging. The collagen membrane exhibited slight tissue reaction and completely degraded at 45 days. The polylactic acid-polyglycolic acid membrane infiltration increased and markedly wrapped up with tissues. The nHAC membrane has good biocompatibility and biodegradability in vitro, which meets the criterion of guided bone regeneration. Related Articles | Metrics

Select

Security evaluation of argentation medical polypropylene mesh in vivo Zou Zhong-hui, Zhao Yu, Sun Yi-lai 2010, 14 (42):  7839-7842.  doi: 10.3969/j.issn.1673-8225.2010.42.012 Abstract ( 345 )   PDF (335KB) ( 459 )   Save BACKGROUND: To reduce the infection of hernia repair mesh, the research group combined silver with medical polypropylene (PP) mesh, to obtain good antibacterial properties, thus not only reducing infection rates of hernia repair mesh, and further applying to potential contaminated and contaminated wounds, widening the application range of tension-free hernia repair. OBJECTIVE: To evaluate the security of medical PP mesh implanted in animals. METHODS: According to the biological and animal experiments recommended by international standards (ISO 10993 series) and national standard (GB/T 16886 series): After the argentation PP mesh was implanted in rabbits, we observed rabbit body weight, death, inflammation, blood biochemistry, liver and kidney function indicators at different periods. Hepatic tissue pathological sections were evaluated for acute, subacute and chronic toxic reactions. RESULTS AND CONCLUSION: After the argentation PP mesh was implanted, the rabbits had no obvious toxic reactions or death. There was no significant difference between the experimental group and control group in blood inflammatory, blood biochemistry, liver and kidney function indicators and liver tissue hematoxylin-eosin staining (P > 0.05), the mesh meets the transformation rule of general inflammation indicators. Argentation medical PP mesh has a good safety in vivo. Related Articles | Metrics

Select

Cellular compatibility of strontium-doped calcium polyphosphate Song Yan-cheng, Zeng Chun, Jin Wen-tao, Cai Dao-zhang, Wan Chang-xiu, Pei Fu-xing 2010, 14 (42):  7843-7848.  doi: 10.3969/j.issn.1673-8225.2010.42.013 Abstract ( 374 )   PDF (723KB) ( 420 )   Save BACKGROUND: It is reported that strontium-doped calcium polyphosphate with controllable degradability and enough mechanical strength could be synthesized by adding trace strontium into biodegradable calcium polyphosphate due to the modulation of material structure, such as pore size and porosity. OBJECTIVE: To study the cellular compatibility of strontium-doped calcium polyphosphate to osteoblasts. METHODS: The rabbit osteoblasts were co-cultured in vitro on the strontium-doped calcium polyphosphate, their morphology and biology were studied. MTT assay was applied to determine the osteoblast vitality in strontium-doped calcium polyphosphate and alkaline phosphatase activities were detected. RESULTS AND CONCLUSION: Under inverted microscope, scanning electron microscopy and confocal laser microscopy, the co-cultured osteoblast adhered, proliferated and grew normally on the surface and pores of strontium-doped calcium polyphosphate, and secreted extracellular matrix and massive microvillus on the cell surface. The osteoblast grew well on strontium-doped calcium polyphosphate; meanwhile, cellular function was shown to be well by MTT assay and alkaline phosphatase activities, 1% strontium-doped calcium polyphosphate achieve the maximum of cellular proliferation activity and alkaline phosphatase activities, no toxicity on osteoblasts and good cellular compatibility. Related Articles | Metrics

Select

Axial stability of lateral-hole dynamic hip screw fixation using type Ⅲ polymethylmethacrylate bone cement argumentation Wang Hong-bing, Xu Rui-sheng, Wang Xue-song, Wu Jie-shi, Xue Jun, Yuan Feng-lai 2010, 14 (42):  7843-7846.  doi: 10.3969/j.issn.1673-8225.2010.42.037 Abstract ( 198 )   PDF (291KB) ( 438 )   Save BACKGROUND: Dynamic hip screw (DHS) is the commonest instrument for treatment of osteoporosis intertrochanteric fracture in aged patients, but the fixation is strongly impacted by osteoporosis, leading to a higher failure. OBJECTIVE: To study the fixation effect of a lateral-hole DHS together with bone cement argumentation by biomechanical test. METHODS: Lateral-hole DHS were designed by drilling four lateral holes in the thread part of the screw. Bone cement was injected into femoral cancellous bone via DHS “central hole-lateral hole”. Biomechanical study with axial loading was performed in six matched pairs of fresh frozen human cadaver femurs, unstable intertrochanteric fracture models were produced, then each paired model was randomly distributed to lateral-hole DHS fixation together with bone cement argumentation and standard DHS fixation group. Biomechanical study of “load-strain” and “load-displacement” test, anti-torsion and pull-out strength were performed. RESULTS AND CONCLUSION: There was no statistical difference of biomechanical strength between lateral-hole DHS fixation together with bone cement argumentation group and standard DHS fixation group; axial loading “load-strain” test showed the strain at the tension side in the bone cement argumentation group was significantly less than that in standard DHS fixation group (t=2.795, P < 0.05). The same result was seen in the pressure side (t=2.621, P < 0.05). When axial loading increased to 600 N, vertical displacement decreased by 31% and horizontal displacement decreased by 29% in bone cement argumentation group as compared with standard DHS fixation group, with significant difference (P < 0.05). The augmentation technique of injecting bone cement to femoral head through central channel and lateral holes of DHS can significantly increase biomechanical strength of DHS fixation for intertrochanteric fracture. Related Articles | Metrics

Select

Biocompatibility evaluation of β-type titanium alloys Zhang Ming-hua, Yu Zhen-tao, Zhang Dian-zhong, Jing Wen-sen, Long Hua 2010, 14 (42):  7849-7853.  doi: 10.3969/j.issn.1673-8225.2010.42.014 Abstract ( 365 )   PDF (424KB) ( 544 )   Save BACKGROUND: Previous studies have validated the good biocompatibility and strong corrosion resistance of titanium and titanium alloys, β titanium alloy has become the most attractive metal biomedical materials due to high mechanical strength and low elastic modulus. OBJECTIVE: To evaluate the biocompatibility of two new β-type titanium alloys: TLE (Ti-(3-6) Zr-(2-4) Mo-(24-27) Nb) and TLM 2 (Ti-(1.5-4.5) Zr-(0. 5-5.5) Sn-(1.5-4.4) Mo-(23.5-26.5) Nb). METHODS: Thirty healthy adult New Zealand rabbits were involved in this study and randomly divided into two groups: subcutaneous implant group and intramuscular implant group. The two new β-type titanium alloys (TLE, TLM 2) were made into cylindrical test pieces, and implanted into thigh subcutaneous tissue and back muscles in rabbit respectively. The contrast materials (Ti-6Al-4V) were implanted into the opposite side in the same animals. According to GB/T16886.6-1997 standard, the samples were taken at 1, 2, 6, 12 and 24 weeks after the implantation to observe fibrous capsule morphology. Interfacial condition between test pieces and surrounding tissues was observed in light microscope, and histological examinations were carried out through hematoxylin-eosin staining. RESULTS AND CONCLUSION: At 2, 6, 12, 24 weeks, vascularized capsules formed around specimens, and became thinner and transparent along with the implantation time prolonged, the number of capillaries in the capsules was also increased. The capsule thickness of the intramuscular implant group was less than subcutaneous implant group in 6, 12 weeks. Inflammatory cells included mainly neutrophils, macrophages, multinucleated giant cells, lymphocytes and plasma cells. With the time went, the number of inflammatory cells decreased, the number of neutrophils was significantly reduced at 12 weeks, lymphocytes and plasma cells gradually decreased with time, there was no neutrophil at 24 weeks. The two new β-type titanium alloys (TLE, TLM 2) have good biocompatibility and extensive clinical application outlook in medicine. Related Articles | Metrics

Select

Preparation and characterization of poly-L-lactic acid/chitosan fibers composite scaffold Wang Xue-jun, Lou Tao, Song Guo-jun 2010, 14 (42):  7854-7856.  doi: 10.3969/j.issn.1673-8225.2010.42.015 Abstract ( 369 )   PDF (334KB) ( 370 )   Save BACKGROUND: Poly-L-lactic acid (PLLA)/chitosan fiber composite scaffold could enhance the mechanical property of the scaffold, buffer the acid product of PLLA degradation, improve the biocompatibility, thus meeting the requirement of tissue engineering scaffolds. OBJECTIVE: To fabricate PLLA/chitosan fibers composite scaffold for tissue engineering. METHODS: The PLLA/chitosan fibers composite scaffold was prepared by thermally induced phase separation method. The micro-morphology, porosity, compressive modulus, degradation and protein adsorption of the scaffold were investigated. RESULTS AND CONCLUSION: The morphology of composite scaffolds showed a combined nanometer and micrometer structure. Adding chitosan fibers to PLLA network can enhance the compressive modulus and protein adsorption of PLLA/chitosan fiber composite scaffold, increased 275% and 112% compared with those of a pure PLLA scaffold. Experiment of the in vitro degradation demonstrated that pH value of composite scaffolds degradation solution declined more slowly with the time. The PLLA/chitosan fiber composite scaffold can enhance the compressive modulus and protein adsorption, also buffer the pH decline during PLLA degradation process, and effectively reduce the indolent inflammation induced by acid product. Related Articles | Metrics

Select

Drug concentration and wall shear stress distribution in curved coronary artery with drug-eluting stents Guo Meng, Jiang Wen-tao, Fan Yu-bo, Zheng Ting-hui, Chen Jun-kai, Yan Fei 2010, 14 (42):  7857-7860.  doi: 10.3969/j.issn.1673-8225.2010.42.016 Abstract ( 312 )   PDF (1005KB) ( 591 )   Save BACKGROUND: The post-implantation restenosis of stent, which is one of the main treatments of vascular occlusive disease, has restricted the further development of drug eluting stent. OBJECTIVE: To clarify the distribution law of drug concentration and wall shear stress distribution after drug-eluting stent was embedded in a curved coronary artery, so as to prefect the clinical application of drug eluting stent theoretically. METHODS: The drug concentration and wall shear stress were numerically investigated at three different diffusion rates after drug-eluting stent was embedded in a curved coronary artery. RESULTS AND CONCLUSION: The artery twisting and stent placement had great impact on the drug diffusion concentration field, while no influence on the change of drug diffusion rate. The asymmetric flow pattern resulted in higher drug concentrations along the inner artery and downstream artery compared with the outer and upstream arteries, respectively. The low wall shear stress and drug concentration on artery wall near the outer stent made these locations (especially the upstream region) the high-risk areas to induce restenosis. Results indicated that drug distribution on stent surface could be optimized according to the flow pattern. Drug coating may be increased on outer wall and upstream while decreased on inner wall and downstream to make full use of the drug moving downstream, and reduce the radial links while increase the drug dose. Therefore the drug distribution near artery wall could be more rationale. In that case it not only can reduce drug doses but also can be helpful to control intimal hyperplasia. Related Articles | Metrics

Select

Effect of gold-plated layer treatment on the surface properties of medical Ni-Cr alloy Chen Guang, Yu Zhan-hai, Ma Xin, Zhang Xuan, Yin Li-hua, Zhang Ju-mei 2010, 14 (42):  7861-7864.  doi: 10.3969/j.issn.1673-8225.2010.42.017 Abstract ( 367 )   PDF (383KB) ( 471 )   Save BACKGROUND: Nickel-chromium alloy exists for a long term in body fluid, which is a specific electrolyte environment, the precipitation of nickel ions is especially evident, leading to not only allergic reactions, but also certain teratogenic and carcinogenic effects. Surface modification on nickel-chromium alloy can theoretically improve the safety of nickel-chromium alloy. OBJECTIVE: To determine the amount of Ni2+ released of medical nickel-chromium alloys, which was electroplated with non-cyanogen gold coating treatment. METHODS: A total of 50 nickel-chromium alloy specimens were randomly divided into nickel-chromium alloy with non-cyanogen gold-plated group and nickel-chromium alloy group. The specimens were soaked in artificial saliva environment at pH 4.8 and pH 7.0 respectively, the nickel ion precipitation was detected using AA-240 atomic absorption spectronphotometer. RESULTS AND CONCLUSION: The nickel ion precipitation from non-cyanogen gold-plated nickel-chromium alloy specimens was significant decreased compared with unplated specimens in artificial saliva environment at pH 4.8 and pH 7.0 (P < 0.05). The non-cyanogen gliding may reduce the nickel ion precipitation, the stability of medical nickel-chromium alloy surface is improved. Related Articles | Metrics

Select

Influence of advanced oxidization modification on nickel-titanium alloy surface on adherence of streptococcus mutans and candida albicans Yin Li-hua, Yu Zhan-hai, Chen Guang, Ma Xin 2010, 14 (42):  7865-7868.  doi: 10.3969/j.issn.1673-8225.2010.42.018 Abstract ( 351 )   PDF (283KB) ( 396 )   Save BACKGROUND: There are various current methods for nickel-titanium alloy modification, with the aim to gain broader clinical application according to clinical use requirements for nickel titanium alloy, based on various methods of increasing biological safety, biocompatibility and corrosion resistance of nickel-titanium alloy. OBJECTIVE: To determine the adherence of streptococcus mutans and candida albicans on material surface and field planting number after advanced oxidization modification on nickel-titanium alloy, and to analyze the influence of advanced oxidization modification on the microbial adherence on alloy surface. METHODS: Polished and modified nickel-titanium groups were placed in culture mediums which contained streptococcus mutans (type C, ATCC25175) and candida albicans (ATCC7661). After 24, 48 and 72 hours, the test pieces were taken out, the sample solution was diluted ten folds, 0.1 mL dilution solution was incubated in the culture medium, colony formation units were counted. RESULTS AND CONCLUSION: As time passed, the microbial adhesion levels were increased both in the polished groups and the modified groups. At the same time, the adhesion level in modified groups was significantly less than that in polished groups  (P < 0.01). Advanced oxidation modification of nickel-titanium alloy in the oral environment can significantly inhibit the bacterial adhesion on the nickel-titanium alloy surface. Related Articles | Metrics

Select

Influence of different surface treatments on shear bond strength of zirconia ceramic to resin cement Zhang Lei, Hu Shu-hai, Ren Xiang, Zuo En-jun 2010, 14 (42):  7869-7872.  doi: 10.3969/j.issn.1673-8225.2010.42.019 Abstract ( 275 )   PDF (386KB) ( 433 )   Save BACKGROUND: At present the surface treatment of zirconia ceramics remains controversial. Some scholars believe that the traditional silanization treatment can not improve the bond strength of zirconia ceramics, while it has reported that silanization treatment or treatment after sandblast can improve the bond strength of zirconia ceramics. OBJECTIVE: To evaluate the effect of different surface treatments on bond strength of zirconia ceramics to resin cement, and to find proper surface treatment for bonding oral zirconia ceramic. METHODS: According to surface treatment, 50 zirconia ceramic sheets (15 mm×10 mm×3 mm) after sintering were divided into five groups: control group (no treatment), silane coupling agent group, sandblast group, sandblast plus silane coupling agent group, sandblast plus silica coating and silane coupling agent group. All samples were bonded to resin cement and subjected to a shear bond strength test in a fatigue testing machine. Fracture mode of each sample tested was observed. RESULTS AND CONCLUSION: Shear bond strength values of four experimental groups was significantly increased compared with control group (P < 0.05), reached the peak in sandblast plus silane coupling agent group. Except for sandblast group and sandblast plus silica coating and silane coupling agent group, sandblast plus silane coupling agent group and sandblast plus silica coating and silane coupling agent group (P > 0.05), the significant differences were showed between every two groups (P < 0.05). Sandblast and silane coupling agent can effectively enhance the shear bond strength of zirconia ceramic to resin cement. Sandblast combined with silane coupling agent is the most proper surface treatment for bonding zirconia ceramic. Silica sol cannot affect bond strength of zirconia ceramic to resin cement. Related Articles | Metrics

Select

Periodontal tissue engineered scaffold materials fabricated with zein Liu Jian, Wu Jing-jing, Li Na, Yang Feng-ying, Xu Yan-zhi 2010, 14 (42):  7873-7877.  doi: 10.3969/j.issn.1673-8225.2010.42.020 Abstract ( 335 )   PDF (604KB) ( 509 )   Save BACKGROUND: Zein with a unique solubility, heat resistance, film-forming, antimicrobial and antioxidant activities, can be used for moisture proofing, oxygen barrier, anti-UV, anti-static electricity. It has become a source of medical and biotechnology raw materials. OBJECTIVE: To fabricate zein scaffolds and to explore the suitability of zein as scaffolds for periodontal tissue engineering. METHODS: Zein porous scaffold was made using the solvent casting/particulate leaching method. Scanning electron microscopy was used to observe the fracture surface and the pore size of zein scaffold. The porosity of zein scaffold was measured by liquid displacement method. Human periodontal ligament cells were cultured in vitro using method of tissue piece, then cultured with different concentrations of extracted liquid of zein. MTT assay was used to calculated the relative growth rate of periodontal cells at 24, 48, 72 hours and to evaluate the cytotoxicity. At the third passage, the cell suspension was incubated on zein scaffold at a density of 3.5×107/L. RESULTS AND CONCLUSIONS: Zein scaffold displayed a sponge-like structure with a high porosity and sufficient thickness. The porosity and pore size of zein scaffold can be controlled by changing the porogen particles dosage and size. Zein porosity was up to 64.1%-78.0% and zein pores were well-distributed, interconnected, and opened. Human periodontal ligament cells cultured with extracted liquid of zein have good activities. The toxicity of zein scaffold was graded as 0-1. Periodontal ligament cells displayed the full stretching and vigorous growth under scanning electronic microscope. All these prompted that zein scaffold fabricated using the solvent casting/particulate leaching method has high porosity, opened pore wall structure, and good cell compatibility. Related Articles | Metrics

Select

Titanium versus polymethyl methacrylate resin complete denture base A phonology evaluation Yao Xi1, Xie Lei, Lu Zhi-yue 2010, 14 (42):  7876-7980.  doi: 10.3969/j.issn.1673-8225.2010.42.045 Abstract ( 268 )   PDF (251KB) ( 636 )   Save BACKGROUND: Several studies have demonstrated that the range, thickness and morphology of oral prosthesis directly influence patient’s phonetic function. and titanium base and polymethyl methacrylate (PMMA) resin base yield different influences on phonetic function due to different thicknesses of materials. OBJECTIVE: To analyze the phonetic parameters in one complete denture patient who wear titanium base and PMMA resin base simultaneously and investigate the influences of maxillary complete denture base on phonetic function. METHODS: Through the use of computer-based voice analysis software PRAAT4.4.34, frequency value of the first concentrated frequency area when speaking consonant sounds /x, sh, r, zh, ch, j, q/ and voice onset time when speaking consonant sounds /g, k, zh, ch, j, q/ were statistically analyzed in the same patient who separately wear titanium complete denture base and PPMA resin complete denture base, and spectrogram of velar stops between complete denture bases was compared. RESULTS AND CONCLUSION: MMPA resin complete denture base was to some extent poor in promoting the recovery of phonetic function owing to great base thickness. Titanium complete denture base with less thickness in the tongue or palate region would help recovery of phonetic function. Extraction and analysis of phonological parameters, such as frequency value of first concentrated frequency area and voice onset time, using CSL computer-based voice analysis system, would provide objective evidence for lamprophony analysis after wearing complete denture. Maxillary denture with thinner base in tongue and palate regions better promotes the recovery of patient’s phonetic function. Related Articles | Metrics

Select

Drug loading strategies and applications of drug eluting stents Chen Wen-ping, Zhan Hong-bing, Li Zhao-hui 2010, 14 (42):  7878-7882.  doi: 10.3969/j.issn.1673-8225.2010.42.021 Abstract ( 362 )   PDF (320KB) ( 433 )   Save BACKGROUND: Undesirable drug release profile, late stent thrombosis associated with polymer and failure to maintain coating integrity are the main current problems in the field of drug eluting stents (DESs). The most original way to address these problems is to change the drug loading strategies including the choice of drug and drug carrier, as well as coating preparation technology. OBJECTIVE: To review the current loading strategies for DESs and to explore the potential future directions. METHODS: Databases of Elsevier, ACS and Springerlink were retrieved using key words of “stent, drug, coating” to search papers about the DESs coating published from March 2000 to January 2010. Related papers addressing DESs coatings were selected. Articles published in authority journals were preferred in the same field. Totally 445 literatures were initially searched, according to inclusive criteria, 31 literatures were summarized. RESULTS AND CONCLUSION: According to the bonding mode between drugs and carriers, the DESs can be divided into physically incorporated, electrostatically attracted and covalently bonded carriers. Various systems of drugs, carriers, coating preparations were discussed from the perspective of drug release profile and anti-restenosis efficiency, which indicated that a relatively desirable release profile can be achieved by careful choice of drug carrier and coating technology based on the physiochemical properties of the drug to be loaded. The potential future directions provided in this paper represented a new clue for optimizing DESs. Related Articles | Metrics

Select

Interface binding and mechanical strength of nano-hydroxyapatite/gelatin/polyvinyl-alcohol biocomposites Wang Feng, Song En-min, Guo En-yan, Zhao Ping, Lai Qi-hui 2010, 14 (42):  7883-7886.  doi: 10.3969/j.issn.1673-8225.2010.42.022 Abstract ( 408 )   PDF (328KB) ( 475 )   Save BACKGROUND: Chemical composition of nano-hydroxyapatite is close to the bone inorganic ingredients, has a good biological activity and biocompatibility, and can be used to repair damage hard tissue or lesions, has been widely used in plastic surgery and oral restoration. Its wide application as load-bearing implants is limited due to its brittleness. In recent years, nano- hydroxyapatite/organics composites have been widely investigated. OBJECTIVE: To review studies on nano-hydroxyapatite/gelatin/polyvinyl-alcohol composites. METHODS: Databases of Science Direct and CNKI were retrieved between January 1994 and December 2009 using key words of “nano-hydroxyapatite; gel; PVA; composite” in English and in Chinese. Totally 126 related articles were selected. Earlier published, duplicated and similar studies were excluded, 24 articles were summarized. RESULTS AND CONCLUSION: Interaction between three phases in nano-hydroxyapatite/gelatin/polyvinyl-alcohol composites showed polyvinyl-alcohol acts as a crosslink reagent. Due to increasing formation of chemical bonds and complex network structure in three phases, the interface binding and mechanical properties of nano-hydroxyapatite/gelatin/polyvinyl-alcohol composites were improved. Therefore, polyvinyl-alcohol would be a potential crosslink reagent, avoiding the pollution of aldehyde crosslink reagents. Related Articles | Metrics

Select

Retentive force and performance of magnetic attachment Jia Shuang, Wang De-fang 2010, 14 (42):  7887-7890.  doi: 10.3969/j.issn.1673-8225.2010.42.023 Abstract ( 321 )   PDF (287KB) ( 764 )   Save BACKGROUND: Satisfactory clinical effect has been already acquired to strengthen the retention of lower mandible complete denture, removable partial denture and prosthetic appliance utilizing the attraction force of magnet. OBJECTIVE: To summarize the researches about the retention of magnetic attachment in the removable partial denture and complete overdenture. METHODS: A computer search was performed in Medline database (1996-01/2010-01) using key words of “magnetic episomal agent, retention, complete denture, removable partial denture and overdenture” in English, and in CNKI database and Wanfang database (1996-01/2010-01) using key words of “magnetic attachment, retention, complete denture, removable partial denture and overdenture” in Chinese. RESULTS AND CONCLUSION: There are 175 literatures about the retention of magnetic attachment, 72 Chinese literatures and 103 English literatures. Too old, repeated and similar studies were excluded, 33 literatures are included fitting the criteria. The magnetic attachment can significantly increase the retention of the lower mandible complete overdenture and removable partial denture. It is therefore required to understand the influence of the distal alveolar bone absorption on the retention and function of the magnetic attachment overdenture, as well as the meliorative effect on partial buffering. Many scholars have modified the materials and structure of magnetic attachment, so as to enhance the retention. Further studies are needed to further determine the retention and function of the magnetic attachment. Related Articles | Metrics

Select

Modification and application of medical poly(lactic acid) materials Fan Guo-dong, Zhang Chun-mei 2010, 14 (42):  7891-7894.  doi: 10.3969/j.issn.1673-8225.2010.42.024 Abstract ( 439 )   PDF (360KB) ( 682 )   Save BACKGROUND: Poly(lactic acid) is an aliphatic polyester with good biocompatibility and biodegradability. The main modified methods of poly(lactic acid) are chemical modification, physical modification and composite materials. OBJECTIVE: To review the various modified methods and application research of poly(lactic acid), to put forward research direction of poly(lactic acid) materials. METHODS: The Science Direct database, NSTL series database and full text database of Chinese Academic Journal from January 1999 to March 2010 were searched by computer for the articles of poly(lactic acid) modification, using “PLA, modification, medicine” in English and Chinese in title and summary as key words. Articles related to poly(lactic acid) modification were selected, those published recently or in the authoritative magazine were preferred in the same field. Totally 246 articles were searched after primary screen, according to the inclusive criteria, 46 articles were involved in review. RESULTS AND CONCLUSION: Understanding of poly(lactic acid) modification is conducive to elect a more reasonable modifier and modified method, so that the mechanical and thermal properties of poly(lactic acid) are improved, and degradable cycle is controlled according to needs. Through the review of poly(lactic acid) modification, new product development and expanded application of poly(lactic acid) materials in medical field can be guided. Related Articles | Metrics

Select

Regeneration membrane materials of periodontal guided tissues Ge Liu-ying, Zhao Li-fen, Duan Kai-wen 2010, 14 (42):  7895-7898.  doi: 10.3969/j.issn.1673-8225.2010.42.025 Abstract ( 479 )   PDF (338KB) ( 729 )   Save BACKGROUND: Guided tissue regeneration membrane is the key material in periodontal regeneration techniques, it guides gingival tissue growth clinically, excludes the epithelium from the periodontal defect, and provides an isolated space for the selective re-population of periodontal ligament, bone and cementum from the surface of dental root. OBJECTIVE: To summarize the progress of guided tissue regeneration membrane and to provide reference evidence for carrying out guided tissue regeneration membrane clinically. METHODS: Using “periodontal barrier membrane, guided tissue regeneration” in English and “guided tissue regeneration, periodontal” in Chinese as the key words, Pubmed database and CNKI database form January 2005 to May 2010 were searched for article related to clinical studies and animal experiments of guided tissue regeneration membranes. Totally 190 literatures were screened out by computer, according to inclusive and exclusive criteria, 25 documents were involved for analysis. RESULT AND CONCLUSION: Because of the non-degradable materials, the first generation of guided tissue regeneration membranes need a second surgery to take out, thus aggravating the pains and impacting the healing. The present guided tissue regeneration membranes tend to the biodegradable materials, the pure natural bioplymers can not meet all needs of guided tissue regeneration membranes due to the property defects, while medical polymer materials, a combination with synthetic polymers, may exhibit excellent properties of the two and satisfy the clinical application. Although biological functional membranes are now under experimental study, the addition of specific agents as antibiotics, growth factors, adhesion factors, etc, conduces the periodontal tissue regeneration to promote the cell growth and induce the cell differentiation initiatively. Related Articles | Metrics

Select

Application of nano-silver antibacterial technology in clinical healthcare He Wei, Zhang Fa-ming, Fan Zhi-ning 2010, 14 (42):  7899-7902.  doi: 10.3969/j.issn.1673-8225.2010.42.026 Abstract ( 469 )   PDF (281KB) ( 1547 )   Save BACKGROUND: As a new type of inorganic antibacterial materials, nano-silver has strong antibacterial effect and safety on human body. OBJECTIVE: To summarize the structural properties, antimbacterial mechanisms, bio-safety, medical applications and further development of nano-silver, and to explore extensive and effective application of nano-silver materials. METHODS: Articles about antibacterial mechanism and bio-safety of nanosilver were retrieved from PubMed database with the key words of “nanosilver; antibacteria; biofilm; bio-safety” from January 1997 to March 2010. articles related to antibacterial effect and bio-safety of nanosilver, as well as bacterial biofilm were included, those published in the authoritative journals or recently published were preferred in the same field. After primary screen, 123 articles were retrieved, 42 of them in accordance with inclusive criteria were included in the final analysis. RESULTS AND CONCLUSION: The nano-silver materials are prone to contact with pathogenic microorganism due to quantum effect, small size effect and great specific surface area, therefore displaying more biologic effect and more disadvantages such as wide antibacterial range and long disinfection time. Further research on the broad-spectrum antibacterial mechanism of nanosilver would provide a theoretical and experimental basis for the development of safe, reliable, broad-spectrum antibacterial nano-materials and nano-drugs, can open up new ways of bacterial infection treatment prevention and treatment for the mankinds. Related Articles | Metrics

Select

Material science characteristics and biocompatibility of drug-eluting stents Zeng Wei-jie, Zhi Qiao-yuan 2010, 14 (42):  7903-7906.  doi: 10.3969/j.issn.1673-8225.2010.42.027 Abstract ( 452 )   PDF (281KB) ( 433 )   Save OBJECTIVE: To describe the materials science of drug eluting stents, and to analyzes its biocompatibility. METHODS: A computer research of PubMed database and China Academic Journal Full-text database was performed for articles about materials science and biocompatibility of drug eluting stents, using “cardiovascular, drug delivery, rapamycin, paclitaxel, coronary artery, biocompatibility, stents” as the Chinese key words. The literatures were primarily checked, and the citations of each literature were looked over. Duplicated study or Meta analysis was excluded. RESULTS:  ① The drug-eluting cardiovascular stents are updated with aim to improve the biocompatibility and biomechanical properties. ② Cardiovascular stents biocompatibility is a complex chain process, blood compatibility and tissue compatibility are two basic elements for the assessment of the biocompatibility. ③ Analysis of mechanical properties of cardiovascular stents using finite element analysis provides helpful reference for the optimal design of future stent. CONCLUSION: The study involved drug-eluting stents is an interdisciplinary crossing of pharmacology, biology and materials science, it is the key problems urgent to be solved in study of controlled release drug delivery system that to investigate the mechanism underlying drug controlled-release carrier, to find drug controlled-release carriers with better blood compatibility, and to enhance bonding strength between controlled-release carriers and the body. Related Articles | Metrics

Select

Tissue engineered nerve constructed with different materials and its application Zheng Sheng-zhe, Lu Lei, Song Lei 2010, 14 (42):  7907-7910.  doi: 10.3969/j.issn.1673-8225.2010.42.028 Abstract ( 338 )   PDF (362KB) ( 400 )   Save OBJECTIVE: To evaluate the performance of tissue engineered neural scaffolds and their use in repair of neural injury. METHODS: Using “tissue engineering, tissue engineering nerve, artificial nerve, materials, repairing of neural injury” in Chinese and in English as the key words, a computer research was performed for articles between January 2000 and March 2010 about tissue engineering nerve scaffold material properties and its application in neural injury repair, duplicated study or Meta analysis were excluded. RESULTS: A total of 20 articles mainly discussed the types and properties of tissue engineering nerve scaffold materials. Autologous nerve graft can be used as an ideal method applied to nerve tissue engineering, it not only has good biocompatibility, biodegradability and high affinity, also promote nerve growth factor growth and tissue repair, but the source is limited. Gelatin has no antigenicity, good biocompatibility, and can be completely biodegradable, achieve self-repair of nerve itself. Chitosan is a basic amino polysaccharide only greatly present in natural polysaccharide, has good biocompatibility, biodegradability and no toxicity, but still fails to meet the needs of being fully compatible. Nano-modification technology is expected to be used in following generation of tissue engineering nerve graft. CONCLUSION: With the development of polymer materials science, more and more biodegradable synthetic materials have been shown to support neural regeneration, but an ideal nerve repair material is absent. It is a key to find a good neural scaffold that has a degradation rate to match neural regeneration speed, the best porosity, tube thickness, shape and so on, while nerve scaffolds achieve the greatest extent on the promotion of neural regeneration through the optimal choice with seed cells and neurotrophic factors. Related Articles | Metrics

Select

Selection and biocompatibility of tissue engineered ligament scaffolds Li Cheng-guo 2010, 14 (42):  7911-7914.  doi: 10.3969/j.issn.1673-8225.2010.42.029 Abstract ( 272 )   PDF (344KB) ( 388 )   Save OBJECTIVE: To summarize the major biomaterials and research progress for the repair of ligament injury, to emphasize the type of ligament injury, to evaluate the properties and applications of various biomaterials for tissue engineered scaffolds applied in the repair of sports ligament injury, and to find a reasonable tissue engineered ligament scaffold. METHODS: A computer research of PubMed database and Wanfang database between January 1999 and July 2010 was performed for articles about biological materials applied in tissue engineered ligament scaffolds, using the Chinese key words of “ligament reconstruction, bio-materials, artificial ligaments, tissue engineering, scaffolds” and English Keywords of “cruciate ligament, LARS artificial ligament, ligament reconstruction”. Duplicated research, reviews or Meta analysis were excluded, finally 19 articles were involved in the evaluation. RESULTS: The selection and biocompatibility of scaffolds for tissue engineering have been discussed, although the present study has achieved great progress, it is still only in the initial stage, and long away from large-scale clinical application. CONCLUSION: The natural and synthetic polymer scaffolds for tissue engineering have its own advantages and disadvantages, most are still in the research stage and have not been applied to clinical practice, so improving their performance as a scaffold is one of the future study directions. Related Articles | Metrics

Select

Surface modification of artificial ligaments and their application in knee cruciate ligament reconstruction Zhao Xu-hui, Wang Fang 2010, 14 (42):  7915-7918.  doi: 10.3969/j.issn.1673-8225.2010.42.030 Abstract ( 262 )   PDF (290KB) ( 469 )   Save OBJECTIVE: To review the surface modification techniques of artificial ligaments and its efficacy in reconstruction of knee joint cruciate ligament. METHODS: A computer research was performed in Wanfang database (http://www.wanfangdata.com.cn/) from January 2000 to August 2010 to retrieve articles about the surface modification techniques of artificial ligaments and its application in reconstruction of knee joint cruciate ligament, using key words of “artificial ligament, surface modification, cruciate ligament” in Chinese. Repeated study, general review or Meta analysis were excluded, 33 literatures were screened into the evaluation. RESULTS: The surface modification of biomaterials is a complicated system, needs both material science and biological science requirements, achieving the desired surface modification should design he surface topology structure-specific recognition- hydrophilic/hydrophobic balance-protein adsorption. Current surface modification techniques are mainly fixed peptide, fixed proteins, laser surface modification, radiation grafting, ion implantation, grafting modification. Through biological materials surface modification, cell adhesion is enhanced, cell proliferation is also promoted. CONCLUSION: The artificial ligament surface modification technology may achieve remarkable results to improve the biocompatibility of artificial materials, with a good application prospect. Related Articles | Metrics

Select

Biocompatibility and biodegradability of spinal cord anti-adhesion membrane Ju Chuan-guang 2010, 14 (42):  7919-7922.  doi: 10.3969/j.issn.1673-8225.2010.42.031 Abstract ( 336 )   PDF (365KB) ( 425 )   Save OBJECTIVE: To evaluate the biocompatibility and biodegradability of tissue engineering material spinal cord anti-adhesion membrane. METHODS: A computer search of PubMed database (http://www.ncbi.nlm.nih.gov/PubMed) and CNKI Database (www.cnki.net/index.htm) was performed by the first author using “biocompatibility; chitosan; spinal cord; biological materials” in English and in Chinese as key words. Articles related to the materials science, biocompatibility and application of the key words were included, those recently published or published in the authority journals were preferred in the same field. A total of 42 literatures were involved. RESULTS: Prevention and reduction of epidural scar adhesion after spinal surgery have been a research focus. Anti-adhesion material implanted is the main method of preventing and reducing epidural scar adhesion. Ideal anti-adhesion materials should have good biocompatibility, no inflammatory response, no rejection; can effectively cover the surgical site, prevent fibrous tissue ingrowth, degrade for appropriate time, have no toxic side effects. Chitosan is a class of potential developing natural biological materials, and obtains more and more attention for the application in biomedical research. CONCLUSION: Chitosan is a type of materials with good biocompatibility and can play a preventive role on epidural adhesion after laminectomy, and remarkably inhibit the epidural collagen proliferation and metabolism after laminectomy, thereby reducing the formation of scar tissue, has broad application prospects in tissue engineering research. Related Articles | Metrics

Select

Clinical application and compatibility evaluation of polymers polysulfone membrane filters An Shu-guang 2010, 14 (42):  7923-7926.  doi: 10.3969/j.issn.1673-8225.2010.42.032 Abstract ( 298 )   PDF (460KB) ( 468 )   Save OBJECTIVE: To evaluate the performance of polymers polysulfone membrane filter and its biocompatibility with the host after implantation, and to provide evidence for its clinical application. METHODS: Using “hemodialysis, dialysis membrane materials, histocompatibility, blood compatibility, polyethersulfone” in English and in Chinese as the key words, a computer search was performed between January 2006 and March 2010. Articles related with the biomaterial’s compatibility with host were included; duplicated studies or Meta analysis articles were excluded. Totally 30 articles mainly discussed the properties and applications of polysulfone membrane filter material. RESULTS: At present, various types of new membrane materials are continuously developing, some have already applied in clinical practice or comes soon, such as vitamin E modified dialysis membrane, polymyxin B modified dialysis membrane, chitin membrane, human kidney dialysis devices, and bioactive membrane. Polysulfone membrane filters have been widely used in clinical practice due to good biocompatibility and sealing effect. CONCLUSION: Through strong convection and adhesion effect of polymers, the polysulfone membrane filter can efficiently clear inflammatory transmitter and toxic metabolite products produced in tissue injury process, exclude excess water retained in body, maintain the water, electrolyte and acid-base balance, achieve internal environment stability, improve the function of important organs, regulate immune system. Although polysulfone membrane filters have been widely used, they inevitably exhibit poor compatibility, and can cause inflammation in nearby tissues, result in disease, hemolysis or clotting phenomena. Ideal membrane filter materials, whether the material itself or its degradation products, can produce no inflammation and toxicity, the occluder with good biocompatibility needs further development. Related Articles | Metrics

Select

Coronary stent surface coating materials influence the implant effect Luo Kang-hua, Xu Xiang-dong 2010, 14 (42):  7927-7930.  doi: 10.3969/j.issn.1673-8225.2010.42.033 Abstract ( 280 )   PDF (350KB) ( 409 )   Save OBJECTIVE: To describe the clinical application of intracoronary stent, and to explore the surface coating materials of coronary stent for stent thrombosis and restenosis after implantation. METHODS: Using “intracoronary stent, surface coating, thrombosis, restenosis” in Chinese as the key words, China Academic Journal Full-text database (CNKI: 2002/2008) and Medline databases (Pubmed: 1974/2006) were retrieved online. Meta analysis and reproducible study were excluded. A total of 25 articles were screened out, discussing the progress of intracoronary stent implantation treatment, different surface coating materials and their influence on the thrombosis and restenosis. RESULTS: Drug-eluting intracoronary stent is a common method of treating coronary heart disease, with remarkable effect and rare complications. Intracoronary stent surface coating materials include rapamycin, paclitaxel, heparin, diallyl sulfide, dexamethasone, and non-degradable polymers, they can promote endothelial cells repair, inhibit smooth muscle cells proliferation, prevent stent thrombosis and restenosis, and maintain stent patency. The residual coating materials stimulate smooth muscle cells to proliferate, biodegradable polymer coating which is used in recent years can improve the patency rate of the stent. Heparinized polyurethane coatings, poly lactic acid glycolic acid copolymer rapamycin coating and polysulfone-polyethylene oxide copolymer coating have good histocompatibility, inhibit intimal hyperplasia and improve the restenosis, they are expected to become a new intracoronary stent coating material. CONCLUSION: Intracoronary drug-eluting stent implantation in combination with aspirin and clopidogrel is a good method for coronary revascularization, with the coating materials continuously update; stent patency rates will be further enhanced. Related Articles | Metrics

Select

Application of three new paste types of root canal filling materials in root canal therapy Die Jia-ye, Li Li-wen 2010, 14 (42):  7934-7938.  doi: 10.3969/j.issn.1673-8225.2010.42.034 Abstract ( 422 )   PDF (288KB) ( 647 )   Save OBJECTIVE: To summarize the application of three kinds of new paste type root canal filling materials (Cortisomol, Vitapex, AH-Plus) in root canal treatment at recent years. METHODS: An online search of VIP database was performed for screening articles about three kinds of paste type root canal filling materials (Cortisomol, Vitapex, AH-Plus) in root canal therapy, search time was from January 2006 to August 2010. Key words included Cortisomol; Vitapex; AH-Plus; root canal therapy; root canal filling; complications. Inclusion criteria: ① Paste type root canal filling materials in root canal therapy. ② The experimental results described complications associated with the materials. Exclusion criteria: repeated studies or older literature. A total of 19 literatures were involved according to the inclusion and exclusion criteria. RESULTS: Cortisomol, Vitapex, AH-Plus are superior to zinc oxide eugenol paste which is commonly used in the past, the postoperative failure rate was significantly lower than ZOE zinc oxide eugenol paste. These three kinds of materials have its own characteristics, Cortisomol is the most effective for apical sealing, Vitapex plays an irreplaceable role in root canal treatment of deciduous teeth, AH-Plus is the latest among three paste type root canal filling materials and few reported, future studies focus on the confirmation of its characteristics. CONCLUSION: Three kinds of materials (Cortisomol, Vitapex, AH-Plus) have a high success rate in root canal treatment, and deserve clinical use. Meanwhile, they have their different characteristics and uses, and should be selective in the application. Related Articles | Metrics

Select

Mesh plain biological patch in inguinal hernia repair Gao Sheng-qi 2010, 14 (42):  7935-7938.  doi: 10.3969/j.issn.1673-8225.2010.42.035 Abstract ( 290 )   PDF (409KB) ( 801 )   Save OBJECTIVE: To investigate the application of biological mesh plain patch in the repair of inguinal hernia. METHODS: A computer search of PubMed database (http://www.ncbi.nlm.nih.gov/PubMed) and CNKI database (www.cnki.net/index.htm) was performed by screening “patches, surgery, inguinal hernia" in English and in Chinese as key words in the titles and summaries. Articles related to the material science characteristics, biocompatibility and application effect were included, those published recently or published in the authority journal were preferred in the same field. Totally 25 literatures were involved. RESULTS: According to chemical compositions and biological characteristics, hernia repair materials can be divided into unabsorbable materials, absorbable materials, composite repair materials and bio-based materials. Unabsorbable materials are predominant in the repair materials, and include metal and nonmetal materials. These materials have good biocompatibility, great tensile strength, strong tolerance, no foreign body sensation after implantation. Tension-free hernia repair patch can stimulate the rapid fibroblast response of surrounding tissues, restore and enhance the tissue strength in repair parts, it is more reasonable and more reliable than all kinds of tension suture repair, which takes the altered anatomical structure of the inguinal canal as the prerequisite, and prevents the anatomical basis of hernia recurrence. Clinical research shows that plain patch has well histocompatibility, no rejection, and certain resistance to infection, it is the ideal material of inguinal hernia repair. CONCLUSION: Tension-free repair treatment of inguinal hernia using mesh plain patch is a good surgical approach, with surgical safety, low recurrence rate, little trauma, and few complications. Related Articles | Metrics

Select

Biological properties of four kinds of nose augmentation materials in clinical application: A comparison study Yang Hai-jiang, Yang Rui-min, Yan Ai-chun 2010, 14 (42):  7939-7942.  doi: 10.3969/j.issn.1673-8225.2010.42.036 Abstract ( 261 )   PDF (304KB) ( 611 )   Save OBJECTIVE: To compare the biological characteristics of four kinds of nose augmentation materials, and to provide evidene for clinicians to select the ideal augmentation material. METHODS: A computer search of Wanfang database was performed for articles published from January 1999 to December 2009 about the clinical studies of nose augmentation materials. Repeated study, review or Meta analysis were excluded, 18 literatures were included to evaluate the biological properties of nose augmentation materials. RESULTS: Among a variety of fillings in nasal plastic surgery, autologous cartilage is the most safe and reliable material, but the source limitations restrict its widely application. Polytetrafluoroethylene is a new ideal material for nose augmentation, but it is not available by the majority of affected patients due to the price, at present, solid silicone rubber is still the main material for augmentation rhinoplasty. CONCLUSION: The ideal nose augmentation material should be easily obtained, non-toxic, non-carcinogenic, non-immunogenic, good biocompatible and not easily deformed. Now the widely used solid silicone rubber, polytetrafluoroethylene, autologous cartilage and other materials have advantages and disadvantages, we should select the appropriate augmentation material based on patient’s different conditions and economic situation. References | Related Articles | Metrics

Select

Bone cement leakage in percutaneous kyphoplasty for the recovery of vertebral height Zhang Hui, Zhang Tao, Zhang Ping-fang, Dong Hong, Wang Jian-min 2010, 14 (42):  7947-7950.  doi: 10.3969/j.issn.1673-8225.2010.42.038 Abstract ( 304 )   PDF (368KB) ( 346 )   Save BACKGROUND: The percutaneous kyphoplasty may form a cavity with surrounding relatively tight cancellous bone in vertebral body through balloon compression expansion, can effectively reduce the leakage rate of bone cement, at the same time the expanding balloon contributes to reduce collapsed vertebral body and correct kyphosis. OBJECTIVE: To retrospectively analyze the influence of manual reduction combined with percutaneous kyphoplasty bone cement on fracture leakage and vertebral height restoration in treatment of osteoporotic vertebral compression fracture. METHODS: Thirty-one patients (41 vertebras) with osteoporotic vertebral compression fracture, aged 53-82 years at a mean of 69 years, were treated with manual reduction and percutaneous kyphoplasty from February 2008 to June 2010 in Department of Orthopedics, General Hospital of Huabei Oil Field Company. Prior to operation, the lumbar part was over-extending reduction by manipulation. The postoperative pain relief, vertebral height restoration and bone cement leakage were recorded during follow-up. RESULTS AND CONCLUSION: All the patients were involved in follow-up for 8-13 months, with an average (11±1.6) months. The visual analogue scale was reduced from (6.7±1.9) points preoperation to (1.3±1.2) points postoperation, with significant differences (P < 0.05). The vertebral height was restored from (15.7±5.2) mm preoperation to (20.2±4.5) mm postoperation, with significant differences (P < 0.05). Extra vertebral leakage of bone cement was observed in three vertebrae with no marked clinical symptoms. Manual reduction combined with percutaneous kyphoplasty is a safety method for osteoporotic vertebral compression fracture, for advantages of pain relief, significant restoration of the vertebrae height and minor the leakage of bone cement. Related Articles | Metrics

Select

Bone cement for augmentation of the vertebral body increases the stability of pedicle screw Wu Yun-gang, Shi Zhi-cai, Zhang Ye, Mao Ning-fang, Yu Lin, Guan Jun-jie 2010, 14 (42):  7951-7954.  doi: 10.3969/j.issn.1673-8225.2010.42.039 Abstract ( 219 )   PDF (261KB) ( 658 )   Save BACKGROUND: The treatment of severe osteoporosis with lumbar degenerative diseases is difficult, vertebral body perfusion of bone cement could increase the stability of pedicle screw and spine. OBJECTIVE: To explore the clinical effect of the bone cement augmentation of vertebral body to increase stability of pedical screw for the treatment of severe osteoporosis with lumbar diseases, and to analyze the technical parameters of bone cement infusion and the influence of the fixed segments. METHODS: A total of 39 patients who suffered from osteoporosis with lumbar diseases and underwent posterior decompression and laminectomy were reviewed retrospectively. In surgical procedures the augmentation of vertebral body strength using bone cement and pedicle screw fixation were used. The JOA scores were assessed at pre- and post-operation (6, 12, 24, 36 months), and effective rate of the operation was calculated. The X-ray examination and MRI examination were performed to evaluate the complications. RESULTS AND CONCLUSION: There were no complications such as bone cement leakage, heat emission and toxicity occurring during operation. The operating time was 90-180 minutes with the intraoperative blood loss of 600-1 000 mL. The operating time for one vertebral body was 8-12 minutes with the bone cement volume of 3.5-5.0 mL. The average JOA scores were 11 points pre-operation, 23 points at post-operative one year and 25 points at the final follow-up. The effective rate was 66.7% at one year and 77.8% at final follow-up. During follow-ups, 1 case had suffered from adjacent vertebral compressive fracture, there was no pedicle screws loosen, broken or pulled out. The technology of augmenting vertebral body strength using bone cement and pedicle screw fixation is a reliable method for treatment of osteoporosis with degenerative lumbar diseases. Related Articles | Metrics

Select

Cold plate external fixation for distal radius extension fractures in 96 cases: Comparison with plaster splint external fixation and practitioner external fixation Wu Qiang, Lai Hua-bing, Yang Lin 2010, 14 (42):  7955-7958.  doi: 10.3969/j.issn.1673-8225.2010.42.040 Abstract ( 277 )   PDF (273KB) ( 603 )   Save BACKGROUND: Common external fixation methods for distal radius fracture include plaster external fixation and Chinese medical practitioner, low-temperature thermoplastic brace is a new developed method for external fixation, it remains unclear whether it is superior to other fixation methods. OBJECTIVE: To observe the therapeutic effectiveness on the functional recovery of extension fracture in the distal radius by using low-temperature thermoplastic braces. METHODS: A total of 96 patients with extension fracture in the distal radius were recruited from West China Prosthetic Orthopedic Centre of Sichuan University from December 2007 to January 2010. They were randomly divided into three groups, low-temperature thermoplastic braces, Chinese medical practitioner and plaster splints, with 32 cases in each group. All groups underwent manipulative reduction and suitable functional exercise, as well as medication according to the age, healthy state and injury state of the patients. RESULTS AND CONCLUSION: Compared with low-temperature thermoplastic braces group, the healing rate was significantly reduced in Chinese medical practitioner and plaster splints groups (P < 0.05), the complications and restricted range of motion were significantly increased (P < 0.05). The external fixation with manipulative reduction and low-temperature thermoplastic brace outperformed the conventional approaches using plates and plaster splints. It is safe, effective, functional, and produces less complications which is recommended for extended uses. Related Articles | Metrics

Select

Comparison of sodium alginate microspheres and gelatin sponge embolization for massive hemoptysis due to pulmonary tuberculosis in 143 cases Huang Qin, Tian Yuan, Ao Guo-kun, Tan Zhi-yuan, Liu Jie-ai 2010, 14 (42):  7959-7962.  doi: 10.3969/j.issn.1673-8225.2010.42.041 Abstract ( 357 )   PDF (470KB) ( 503 )   Save BACKGROUND: Among many treatment programs for massive hemoptysis due to pulmonary tuberculosis, the efficacy of embolization is most clear and obvious. There are a variety of plug blocking materials, such as traditional gelatin sponge, polyvinyl alcohol particles, widely used coil, sodium alginate microspheres embolic agent and so on. They have different efficacies. OBJECTIVE: To compare the therapeutic effect of sodium alginate microspheres versus gelatin sponge embolization of bronchial artery for massive hemoptysis due to pulmonary tuberculosis. METHODS: Totally 143 cases of massive hemoptysis due to pulmonary tuberculosis were divided into two groups according to different embolic materials, a gelatin group and a sodium alginate microsphere group. Selective bronchial artery angiography was performed first, superselective bronchial arterial cannulation was done, and finally embolic materials were into the distal bronchial artery for embolization. RESULTS AND CONCLUSION: In gelatin group, 92 target vessels showed a thrombosis, 44 patients (58.7%) were immediately stopped bleeding after embolization, total effective rate was 81.3%. In 2-year follow-ups, 12 cases (25.3%) recurred. In sodium alginate microsphere group, 83 target vessels showed a thrombosis, and 60 patients (89.1%) were immediately stopped bleeding after embolization, total effective rate was 92.6%. In 2-year follow-ups, 5 cases (7.8%) recurred. The immediate hemostatic effect in the sodium alginate microsphere group was significantly better than that of gelatin group (P < 0.05), the cure rate was significantly higher than gelatin group (P < 0.05); the recurrence rate was significantly lower than gelatin group (P < 0.05); total effective rate was significantly higher than gelatin group (P < 0.05). There was no significant difference between two groups regarding the incidence of complications (P > 0.05). The sodium alginate microsphere for bronchial artery embolization is safe and effective to treat for massive hemoptysis due to pulmonary tuberculosis, with low recurrence rate, thus worthy of clinical application. Related Articles | Metrics

Select

Wound care biomembrane for circumcision wound: Pain, healing and complications Liu Hui-lian, Li Zhang-hong, Yang Jun 2010, 14 (42):  7963-7965.  doi: 10.3969/j.issn.1673-8225.2010.42.042 Abstract ( 375 )   PDF (227KB) ( 531 )   Save BACKGROUND: In recent years, different chemical compositions and biological properties of wound care membrane and dressing film have been widely used in clinical practice, a suitable material that not only maintains the wound moistening, but also stops bleeding and pain, prevents infection and promotes wound healing. OBJECTIVE: To observe the efficacy of biological membrane for wound care to promote wound healing after circumcision. METHODS: A total of 90 cases underwent circumcision were randomly divided into 2 groups, in wound care membrane group, the circumcision wound care was aspersed with Ji’an Shuneng spraying and sutured immediately after circumcision, the gauze bandage surface was thoroughly sprayed wet before conventional wound dressing, 2 days postoperation, the gauze was removed. The wounds were exposed and aspersed with Ji’an Shuneng spraying, at lest three times per day, spray coating should promptly supplement after urinating; control group was treated with conventional gauze wound dressing, the dressing was changed every 3 days. RESULTS AND CONCLUSION: Compared with control group, postoperative wound pain score decreased significantly in wound care membrane group (P < 0.05), wound healing was markedly improved (P < 0.05). It is safe and reliable to apply Ji’an Shuneng wound care biological membrane after circumcision, with good analgesic effect, anti-infection and wound healing promotion, while leakage, edema and scar formation are reduced, as well as simple clinical manipulation, thus worthy of clinical application. Related Articles | Metrics

Select

Biocompatibility of a magnesium-zinc alloy implanted in rat cecum Yuan Qing-ling, Yan Jun, Zheng Qi, Zhang Shao-xiang, Zhang Xiao-nong 2010, 14 (42):  7966-7970.  doi: 10.3969/j.issn.1673-8225.2010.42.043 Abstract ( 249 )   PDF (386KB) ( 553 )   Save BACKGROUND: Magnesium alloy studies in orthopedic field have been carried out, and good biocompatibility has been reported. However magnesium alloys have not yet been researched in the intestine. OBJECTIVE: The biodegradable magnesium-zinc alloy samples are implanted around the rat cecum to investigate the biocompatibility in rat. METHODS: Sprague Dawley rats were randomly divided into magnesium alloy group, medical titanium group and the sham-operated group. Then magnesium-zinc alloy samples with the dimension of 5 mm × 1 mm × 1 mm were embedded in the cecum incision in the magnesium alloy group. The medical titanium was embedded in the medical titanium group, and just suture in the sham-operated group. Prior to surgery and at 7, 14, 21 and 28 days after operation, the serum glutamic-oxaloacetic transaminase, creatinine and magnesium ion concentration were examined in each group. X-ray film on implanted region. The pathological changes in liver, kidney and cecum were examined. RESULTS AND CONCLUSION: There were no significant differences in serum glutamic-oxaloacetic transaminase, creatinine and magnesium ion concentrations among each group (P > 0.05). Magnesium-zinc alloy degraded gradually during 28 days. The pathology of liver, kidney and cecum was normal. Results suggested that magnesium-zinc alloy had no obvious effect on the cecum. The degradation time to play a fixed function of time was longer than the intestinal healing time, with good biocompatibility. Magnesium-zinc alloy can be used as anastomotic nail for stomach intestine anastomat. Related Articles | Metrics

Select

Nano-hydroxyapatite/collagen composite co-cultured with bone marrow-derived mesenchymal stem cells for repair of bone defects Zhao Ji-dong, Qian Han-guang, Miao Zong-ning, Zhu Jian-zhong, Peng Wei 2010, 14 (42):  7971-7975.  doi: 10.3969/j.issn.1673-8225.2010.42.044 Abstract ( 304 )   PDF (297KB) ( 425 )   Save BACKGROUND: There have been no effective means for clinical treatment of large regions of bone defects. Nano-hydroxyapatite/collagen (nHAC) composite would provide a new pathway for repair of bone defects owing to its similar structure to natural skeleton and better biocompatibility. OBJECTIVE: To investigate the role of nHAC composite co-cultured with bone marrow-derived mesenchymal stem cells (BMSCs) in repair of bone defects. METHODS: Following isolation and culture, human BMSCs were co-cultured with nHAC composite. Gross observation, histological analysis, and electron microscope observation were performed to analyze osteogenesis for repair of bone defects in the clinic. RESULTS AND CONCLUSION: Human nHAC could greatly proliferate in vitro. X-ray photography revealed that bone defects well healed after implantation of nHAC/BMSCs composite. These findings indicate that BMSCs exhibit osteogenic potential and nHAC is a satisfactory scaffold material for construction of tissue-engineered bone. Related Articles | Metrics