Table of Content

15 January 2010, Volume 14 Issue 3 Previous Issue    Next Issue

For Selected:

Download Citations EndNote Reference Manager ProCite BibTeX RefWorks

Toggle Thumbnails

Select

Cellular compatibility of modified poly-lactic glycolic acid/type-Ⅰ collagen compound scaffold and rabbit ear chondrocytes Zhou Bing-hua, Liao Wen-bo 2010, 14 (3):  381-384.  doi: 10.3969/j.issn.1673-8225.2010.03.001 Abstract ( 267 )   PDF (288KB) ( 590 )   Save null References | Related Articles | Metrics

Select

Analysis of collagenous structures for cartilage tissue engineered scaffolds Li Xia, Chen Lu, Wan Fa-sheng, Li Li-li, Jiang Bo 2010, 14 (3):  385-388.  doi: 10.3969/j.issn.1673-8225.2010.03.002 Abstract ( 321 )   PDF (382KB) ( 636 )   Save BACKGROUND: Various types of collagen affect differentiation and expression of chondrocytes in the process of tissue engineered culture for cartilage. The reliability of cartilage tissue engineering is determined by resource, structure and property of collagen.   OBJECTIVE: To characterizing the structure of collagen type Ⅰ, Ⅱ and Ⅲ, to clarify the structural characteristics of collagen for cartilage tissue repairing and provide guidance for choosing cartilage tissue engineering scaffolds. METHODS: The type Ⅰ and Ⅲ collagen was obtained from neonatal calf skins, and type Ⅱ collagen was obtained from porcine articular cartilage. The differences of structures of collagen type Ⅰ, Ⅱ and Ⅲ were analyzed and compared by FTIR, DSC, SDS-PAGE and picrosirius-red staining. RESULTS AND CONCLUSION: The neonatal calf collagen typeⅠ, Ⅲ and porcine collagen type Ⅱ had the similar functional group. The thermal denaturation temperature of the three type collagen was 104.2 ℃, 99.7 ℃ and 92.5 ℃. SDS-PAGE analysis showed the collagen type Ⅲ percentage in collagen type Ⅰ was (11.29±0.91)%. Picrosirius-red staining exhibited that the collagen type Ⅰ was comprised red and orange raw fibers, with strongly birefringent. Collagen type Ⅲ was lax and thin, greenish fibers, but collagen type Ⅱ was red, loosely cancellated fibers. The functional groups and important characteristics of the three of collagen are similar. However, there are some differences in advanced structure. To analyze the relationships of collagen type Ⅰ, Ⅱ and Ⅲ is important to choose and prepare scaffolds for cartilage tissue engineering. Related Articles | Metrics

Select

Co-application of muscle-derived stem cells and FK-506 influences nerve regeneration and recovery following acellular nerve allograft implantation Lian Xiao-fei, Wang WeI, Zhang Li, Zhang Wan-li, Liu Xin-sheng, Wang Cheng-yue 2010, 14 (3):  389-392.  doi: 10.3969/j.issn.1673-8225.2010.03.003 Abstract ( 515 )   PDF (378KB) ( 567 )   Save BACKGROUND: Muscle-derived stem cells (MDSCs) have been accepted as seeding cells in tissue engineered artificial nerves. Tacrolimus exhibits anti-immunologic rejection and promotes nerve regeneration and recovery. Whether can combine these factors with acellular nerve to form a new bridge that can inhibit immunologic rejection and promote nerve regeneration is uncertain. OBJECTIVE: Using the freeze-thawing combined optimized acellular nerve hypotonic-chemical detergent to prepare acellular nerveallograft scaffold. To explore the effect of co-application of MDSCs and FK-506 on nerve regeneration and function recovery following acellular nerve allograft implantation. METHODS: The sciatic nerve derived from SD rats was prepared nerve bridge after acellular disposal. Gel containing FK-506 and MDSCs was injected into acellular nerveallograft scaffold with 100 μL microsyringe to repair defects. A total of 32 SD rats were randomly divided into 4 groups, with 8 animals in each group. A gap of 10 mm of left sciatic nerve was removed. And then the defects were repaired by extracted nerve graft containing FK-506+MDSCs, MDSCs and FK-506, respectively. In the control group, only hyaluronic acid gel was injected. Sciatic nerve function index (SFI) and electrophysiological exam were performed at weeks 8 and 12 after operation. Gross observation, neurohistological and ultrastructure were observed at week 12 after operation.  RESULTS AND CONCLUSION: Compared with the same time point, the SFI, recovery rate of the motor nerve conduction velocities (MNCV), and myelinated nerve fibers in grafting part and in its distal part in the FK-506+MDSCs group were superior to other groups (P < 0.05). The nerve grafts were in normal size with considerable blood vessels and slightly connected to peripheral tissues. Compared to other groups, the regenerated nerve fiber in the FK-506+MDSCs group was more density with well-arranged order. A great quantity of Schwann cells proliferated in grafting. The density and diameter of myelinated fiber in the middle and distal part of the grafting were all greater than that of MDSCs and FK-506 groups, and there were few connective tissues between microfascicles, which was close to normal level. The co-application of MDSCs and FK-506 enhances peripheral nerve regeneration and functional recovery in acellular nerve allograft graft. Therefore, MDSCs and FK-506 are synergistic factors in peripheral nerve injury repair. Related Articles | Metrics

Select

Tissue engineered spinal cord scaffold material: Optimal pore size of poly lactic-co-glycolic acid scaffolds Xie Qing-song, Xu Xin-long, Wei Xiao-jie, Fu Xiao-jun, Pan Hong-song, Li Li-xin 2010, 14 (3):  393-396.  doi: 10.3969/j.issn.1673-8225.2010.03.004 Abstract ( 337 )   PDF (1153KB) ( 535 )   Save BACKGROUND: Cytoskeleton is a carrier of cell growth, and its pore caliber is one of the most important factors to affect the curative effect of tissue engineered spinal cord. OBJECTIVE: To explore the optimal pore size of poly lactic-co-glycolic acid (PLGA) scaffolds for tissue engineered spinal cord by in vitro culture of neural stem cells (NSCs) and various pore sizes of PLGA scaffolds. METHODS: 50 µL (cell number 1010/L) NSCs suspension at passage 1 was separately seeded on 200-300 µm, 400-500 µm PLGA stent for 7 days. Two sorts of tissue engineered spinal cord were constructed in vitro. Thirty rat models of spinal cord injury were established, and then assigned to 3 groups. The detect sites of these models were filled with above-mentioned spinal cord immediately, but the blank control was not treated with any material. The cells growth and proliferation implanted on PLGA were observed by phase contrast microscope and scanning electron microscope. Relative number of NSCs in two tissue engineered spinal cords was measured by MTT assay. The effects of transplantation with tissue engineered spinal cord were evaluated by the BBB scale. RESULTS AND CONCLUSION: Neural stem cells implanted on different pore size scaffolds were seen growing by phase contrast microscope and scanning electron microscope, with good histocompatibility. After 7-day coculture, absorbance was similar between 200-300 µm PLGA and 400-500 µm PLGA groups (P > 0.05). These indicated that the pore size had no effects on NSC number. At week 4 following transplantation, in the blank control group, neural function was recovered to different degrees in the 200-300 µm PLGA and 400-500 µm PLGA groups. BBB motor functional score was significantly increased (P < 0.05). The pore size of 200-300 µm utilized in fabricating tissue engineered spinal cord has the best transplantation effect as compared to others.  Related Articles | Metrics

Select

Freeze-dried amniotic membrane for repair of dural defects Zhang Nian-ping, Liu Fang, Tian Xue-wen, Zhang Yong 2010, 14 (3):  397-399.  doi: 10.3969/j.issn.1673-8225.2010.03.005 Abstract ( 246 )   PDF (272KB) ( 491 )   Save BACKGROUND: Amnion has been widely used in ophthalmology. Numerous studies have suggested that amnion transplantation did not induce acute immunologic rejection. These indicated that amnion transplantation can be used as a safe material for repair of dural defects. OBJECTIVE: To study the probability of freeze-dried amniotic membrane (FDAM) as a dural substitue. METHODS: Each of the guinea pigs underwent bilateral parietal craniectomy behind the coronal suture and beside the midline to expose the dura. On the right side, a piece of dura mater was removed. The dural defect was covered with a piece of FDAM. The exposed dura on the left was cut and sutured itself as control. The animals in each group were sacrificed at 15, 30, 60 and 90 days after operation, respectively. The implants were harvested and stained with hematoxylin-eosin, and histologically analyzed. RESULTS AND CONCLUSION: After operation, the behavior of all guinea pigs remained completely normal. The wound healing was achieved in all cases. No wound infection, subcutaneous effusion or cerebrospinal fluid (CSF) leakage occurred. The graft was degraded gradually and covered with a sheet of connective tissue. Dural defects repaired with FDAM showed no adhesions to the brain surface. 15 days after operation, plenty of scattered fibroblasts appeared in the dural substitute. 30 days after dural graft implantation, parts of the implant disappeared; meanwhile the hyperplasia of fibrous connective tissue took place in the center part of the dural substitute, without the infiltration of inflammatory cells. 60 days after implantation, a majority of the dural graft was degraded, substituted by fibrous connective tissue which was of hyperplasia and low-grade degeneration, surrounded by a small quantity of giant cells. 90 days after operation, colloidal degeneration happened in the dural substitute, surrounded by ossification tissue and the degenerated fibrous connective tissue. The inflammatory cells were not discovered. The animal experiment proves FDAM to be a safe and applicable dural substitute. Related Articles | Metrics

Select

Effects of stretching-shape recovering process on the cytocompatibility of novel shape memory polyurethane for bone repair Yan Ze-xuan, Luo Yan-feng, Huang Mei-na, Wang Yuan-liang 2010, 14 (3):  400-404.  doi: 10.3969/j.issn.1673-8225.2010.03.006 Abstract ( 294 )   PDF (441KB) ( 603 )   Save BACKGROUND: Shape memory polyurethane (SMPU) may be employed for bone repair capable of resisting stress shielding and bone non-union due to the shape memory effect responding to changed external temperature. Evaluating the cytocompatibility of SMPU is important for its further in vivo experiments and applications. However, few have been done to investigate the cytocompatibility of SMPU after encounted from deforming and shape recovering. OBJECTIVE: To evaluate the osteoblast compatibility of SMPU before and after stretching-shape recovering process. METHODS: Solvent casting method was used to fabricate SMPU films; the obtained SMPU films were stretched to 200%, and then fixed and finally recovered to its original shape at Tg+15 ℃, Tg-15 ℃ and Tg+15 ℃, respectively. Atomic force microscope (AFM) with tapping mode was employed to probe the surface morphology and phase separation of SMPU. Primary osteoblasts at 3-5 passages were seeded on SMPU films in vitro to evaluate the adhesion, proliferation and spreading of osteoblasts. RESULTS AND CONCLUSION: There were obvious and regular phase separation resulted from soft segments and hard segments in SMPU, and some groove-ridge architectures within a scale of micrometers were produced by the stretching-shape recovering process. These special micropatterned structures promoted osteoblast adhesion and proliferation, and also resulted in partially oriented cell growth along the grooves. Shape memory process, i.e. stretching-shape recovering process may obviously change the surface morphology of SMPU films, and suggesting better biocompatibility with osteoblasts. Related Articles | Metrics

Select

Cytocompatibility of nano-hydroxyapatite/bacterial cellulose nanocomposites and its residues Zheng Qi, Xi Ting-fei, Chen Yan-mei, Wang Zhao-xu, Wan Yi-zao, Gao Chuan　 2010, 14 (3):  405-409.  doi: 10.3969/j.issn.1673-8225.2010.03.007 Abstract ( 354 )   PDF (389KB) ( 547 )   Save BACKGROUND: The nano-hydroxyapatite/bacterial cellulose (nHAP/BC) nanocomposites has a good prospect of application in bone tissue engineering, and the bone tissue engineered materials and its degradation products should have excellent compatibility. This study further assessed DAN synthesis cycle using flow cytometry on the basis of evaluating cell compatibility by metabolic 3-( 4, 5-dim ethylthiazo l-2-y l) -2, 5-Dipheny l-2H-tetrazolium (MTT) assay. OBJECTIVE: To evaluate the cytocompatibility of a new-pattern nHAP/BC nanocomposites and its residues.  METHODS: Effects of nHAP/BC nanocomposites and its residues on morphological changes in osteoblasts were observed using in vitro cell culture method. Effects of nHAP/BC nanocomposites and its residues on osteoblast growth and proliferation were evaluated by MTT assay. Cell cycle phase changes were detected using flow cytometry to evaluate material effects on cell proliferation on molecular levels. RESULTS AND CONCLUSION: The nHAP/BC nanocomposites and its residues had neither remarkable effects on cell morphology, nor significant inhibition on osteoblast growth and proliferation. Test of MTT cytotoxicity showed that the average cell proliferation rate was over 80% after treated with the material and its residues, with the cytotoxity grade of 1 (non-toxic). Flow cytometry indicated that the rate of G0/G1 was reduced, and the rates of S, G2/M were increased, and the synthesis of DNA was increased, the cellular growth and repair in osteoblasts was accelerated. These indicated that nHAP/BC nanocomposites have good cytocompatibility, and it will be safe and prospected scaffolds in bone tissue engineering. Related Articles | Metrics

Select

Biomimetic synthesis and cytocompatibility of agar-hydroxyapatite composites Cai Hua-qiong, Li Quan-li, Zhou Jian, Tang Jian, Chen Hui 2010, 14 (3):  410-414.  doi: 10.3969/j.issn.1673-8225.2010.03.008 Abstract ( 394 )   PDF (560KB) ( 444 )   Save BACKGROUND: Studies regarding synthesizing composite bone repair materials with organic macromolecules as mineralizers template are the hot research spot. However, reports concerning using agar as bone repair materials are few. OBJECTIVE: To synthesize a novel agar-hydroxyapatite composite material, and to evaluate its physical and chemical properties as well as cytocompatibility. METHODS:  ①A certain amount of the non-nano-hydroxyapatite in hydrochloric acid solution was added into a certain amount of agar sol, and the reaction system was adjusted with PH value of 7-8. And then the precipitate was lyophilized to obtain the composite of agar-hydroxyapatite. ②The third generation of rat bone marrow stromal cell (BMSC) was co-cultured with agar-hydroxyapatite. And the growth of cells was observed at days 1, 3 and 5 after culture. RESULTS AND CONCLUSION: The results of X-ray diffraction patterns, Fourier transform infrared spectrometer (FTIR), thermal analyzer, transmission electron microscope, and scanning electron microscope showed that agar could manipulate the growth of hydroxyapatite, and hydroxyapatite nanocrystals was equably formed on the agar-fibers with high porosity. The BMSC grew well in the composite and form a clear cytoskeletal at days 3 and 5 after culture. The results reveal that agar-hydroxyapatite composite has good physical and chemical properties and cytocompatibility. Related Articles | Metrics

Select

Biocompatibility of porcine small intestinal submucosa and adipose derived mesenchymal stem cells Yang Hao, Wu Di, Li Shi-he, Zhu Xiao-song 2010, 14 (3):  415-418.  doi: 10.3969/j.issn.1673-8225.2010.03.009 Abstract ( 297 )   PDF (560KB) ( 556 )   Save BACKGROUND: Small intestinal submucosa (SIS) has good compatibility with cells and tissues, and has good degradability. It is an ideal scaffold for tissue engineering. Inducing adipose derived mesenchymal stem cells (ADSCs) seeded on SIS can construct target tissues, which has the potential to be used in clinical treatment. OBJECTIVE: To prepare decellularized porcine SIS matrix, and testify its biocompatibility with rabbit ADSCs cultured in vitro. METHODS: SIS was processed by enzyme digestion-hypertonic saline decellularization, lyophilized at low temperature, and sterilized by gamma radiation. Paraffin sections were used to observe the effect of decellularization of SIS, and the surface structures of SIS were observed by scanning electron microscope (SEM). Rabbit ADSCs were isolated and cultured, and passage 3 ADSCs were seeded onto one side or both sides of SIS. After one week of co-culture, the cell-scaffold composites were observed. RESULTS AND CONCLUSION: SIS was white and semi-transparent film. Paraffin sections showed no cells on SIS matrix; electron microscopy showed loose weave structure of serosal surface and dense packing structure of mucosal surface. After one week of co-cultivation, plenty of ADSCs were observed on the surface of SIS. In ADSCs seeded onto one side of SIS group, a large number of cells grew on the superior surface, and few even no cells were observed on inferior surface of SIS. When ADSCs were seeded onto both sides of SIS, cells adhered to SIS in paraffin sections. Results show that enzyme digestion-hypertonic saline decellulariation can decellularize SIS completely, and SIS can support ADSCs growth. Related Articles | Metrics

Select

Prevention of bone infection using calcium alginate gel compound vancomycin: Do administration routes influence pharmacological action? Yu Hai-quan, Feng Wen-ling, Tian Yu-liang 2010, 14 (3):  419-423.  doi: 10.3969/j.issn.1673-8225.2010.03.010 Abstract ( 370 )   PDF (670KB) ( 381 )   Save BACKGROUND: Systemic administrations are widely used in preventing or curing bone infections, however, it accompanied by great adverse reactions and limited local blood drug levels. Therefore, local administration becomes a research focus, which aimed to explore a carrier possess good biocompatibility and slow-release antibiotics.  OBJECTIVE: To explore the effect of calcium alginate gel compound vancomycin on prevention of bone infection, simultaneously, single drug was injected or implanted into models to compare the results. METHODS: A total of 60 healthy adult New Zealand white rabbits were prepared for osteomyelitis models by injecting Staphylococcus aureus to right tibiae medullaris, and randomly divided into systemic treatment, tricalcium phosphate and calcium alginate gel groups. After model preparation, rabbits in the systemic treatment group were intramuscular injected vancomycin (0.03 g, twice per day, for 4 successive days); in the tricalcium phosphate group, 1 g tricalcium phosphate combined with 0.1 g vancomycin was filled in the defects, sealed with bone wax. In the calcium alginate gel group, calcium alginate gel combined with vancomycin was implanted. Gross observation, radiological image and histological analysis were performed at weeks 4 and 8 after operation. RESULTS AND CONCLUSION: Local swelling and partial sinus were found in the systemic treatment and tricalcium phosphate groups after operation. The pathological slice showed that there were a large number of lymphocytes and some sequestrum in the systemic treatment and tricalcium phosphate groups. However, there was no manifestation of osteomyelitis in the calcium alginate gel group. The results suggested that calcium alginate gel compound vancomycin exhibit superior therapeutic effect on prevention of bone infection to local administration of calcium alginate gel combined with vancomycin or systemic application of vancomycin. Related Articles | Metrics

Select

Sulfonation of polyethersulfone sheets effects on adsorbability of beta 2-microglobulin: Whether the adsorbability changes with increased sulfonation degree? Ma Xing-yu, Sun Xiao-qing, Cheng Li-ping, Sun Shu-dong, Yue Yi-lun, Huang Jia, Mao Hua-yi 2010, 14 (3):  424-428.  doi: 10.3969/j.issn.1673-8225.2010.03.011 Abstract ( 273 )   PDF (529KB) ( 441 )   Save BACKGROUND: Dialysis-related amyloid may occur during long-term dialysis for patients with uraemia, of which the main evocator is β2 -microglobulin (β2 M); therefore, how to eliminate β2M from blood is always the focus of research. OBJECTIVE: To observe ability of removal of β2 -microglobulin (β2M) from serum using two kinds of polyethersulfone (PES) membrane materials with various degrees of sulfonation. METHODS: These materials were incubated in radio-labeled β2 M (125 I-β2M) solution and human serum respectively at appointed time at 37 ℃, and then the amounts of 125 I-β2M and serumβ2M adsorbed by materials were measured by radio immunoassay. RESULTS AND CONCLUSION: In the 125 I-β2M system, amounts of 125 I-β2M adsorbed by the materials decreased in the following sequence PES with high degree of sulfonation > PES with low degree of sulfonation > PES, whatever the source of PES was. In the serum system, amounts of β2M adsorbed reached maximums at 30 minutes and the final adsorptions decreased in sequence of PES with high degree of sulfonation > PES with low degree of sulfonation > PES. Sulfonated PES removed β2M more than PES did and the adsorption of β2M increases with the increase in the degree of sulfonation. Its ability to remove significant amount of β2M may result in less β2M available for incorporation into amyloid. The use of sulfonated PES membranes may lessen the likelihood of development of dialysis-related amyloidosis, which remains a major source of morbidity for patients treated with long-term hemodialysis. Related Articles | Metrics

Select

Effect of chitooligosaccharides on cyclin D1, bcl-xl and bcl-2 mRNA expression in Hela cells Li Xian, Wang Ju, Zhou Chang-ren, Tian Jin-huan, Chen Xiao-jia, Zhao Ming-yan 2010, 14 (3):  429-432.  doi: 10.3969/j.issn.1673-8225.2010.03.012 Abstract ( 269 )   PDF (630KB) ( 946 )   Save BACKGROUND: Studies have shown that chitooligosaccharides have antitumor effect. However, the influence of chitooligosaccharides on cyclin D1, bcl-2 and bcl-xl remains unclear. OBJECTIVE: To observe the inhibition effect of chitooligosaccharides on the proliferation of Hela cells, and the influence on cyclin D1, bcl-xl and bcl-2 mRNA expression. METHODS: Hela cells were stimulated by different concentrations of chitooligosaccharides (0.1, 0.5, 1, 2, 5 g/L). The effects of chitooligosaccharides on Hela cells were detected by CCK8 kit. Using real-time PCR methods, the gene expression of cyclin D1, bcl-xl and bcl-2 mRNA were determined. RESULTS AND CONCLUSION: Chitooligosaccharides inhibited the proliferation of Hela cells. With the concentrations of chitooligosaccharides increased from 0.1 g/L to 2 g/L, the inhibition effects on the gene expression of cyclin D1, bcl-xl and bcl-2 were enhanced, peaked at 2 g/L, and decreased at high concentration (5 g/L). Antitumor activity of chitooligosaccharides may exert through two aspects: it inhibits cyclin D1 mRNA expression to suppress the proliferation of tumor cells; on the other hand, chitooligosaccharides inhibits the expression of bcl-xl and bcl-2 to promote the apoptosis of tumor cells. Moreover, the effects of the former are stronger than the latter. Related Articles | Metrics

Select

Preparation of self-assembly scaffolds via electrostatic attachment of calcium alginate microspheres Chen Wen-bin, Lu Lu, Jiao Yan-peng, Zhou Chang-ren 2010, 14 (3):  433-437.  doi: 10.3969/j.issn.1673-8225.2010.03.013 Abstract ( 310 )   PDF (476KB) ( 636 )   Save BACKGROUND: Microspheric injectable scaffold has a perspective in cartilage tissue engineering; however, it is still limited by in vivo hard forming and microsphere transmigration.  OBJECTIVE: To investigate the feasibility of self-assembly scaffolds by attaching negatively charged calcium alginate microspheres and positively charged chitosan microspheres by electrostatic force. METHODS: The calcium alginate and chitosan microspheres were prepared by emulsion-internal gelation and spray drying technique, respectively. The characterizations of the microspheres were determined by means of scanning electron microscopy, optical microscopy and zeta potential analysis methods. Self-assembly scaffolds were fabricated by mixing the aqueous suspensions of the microspheres with oppositely charged surfaces. The phenomenon of electrostatic attachment was characterized by optical microscopy and scanning electron microscopy, and the elastic compress modulus of the scaffolds was also investigated. RESULTS AND CONCLUSION: The average diameter of the calcium alginate microspheres was 52.5 μm, and the chitosan one was 4.1 μm, respectively. The zeta-potential of the calcium alginate microspheres was -23.5 mv, and the chitosan one was +9.8 mv, respectively. The microspheres were spherical and smooth. The small size chitosan microspheres could attach to the surface of the calcium alginate microspheres and anchor the calcium alginate microspheres together. The elastic compress modulus increased with the increase of solid content of the microspheres, but decreased with the increase of the ionic strength. The elastic compress modulus increased firstly and then decreased with the increase of the mass ratio of m (CHI):m (ALG), and it showed the highest elastic compress modulus when m (CHI):m (ALG) was 2:1. The positively charged chitosan microspheres could attach to the negatively calcium alginate microspheres to form a self-assembly scaffold. Related Articles | Metrics

Select

Effect of heparin slow-release stent implantation combined with myocardium drilling on myocardial regeneration of pigs with acute myocardial infarction Zhang Guang-wei, Liu Xiao-cheng, Shi Rong-fang, Zhao Xiao-bin, Liu Tian-jun, Lü Feng 2010, 14 (3):  438-442.  doi: 10.3969/j.issn.1673-8225.2010.03.014 Abstract ( 231 )   PDF (775KB) ( 428 )   Save BACKGROUND: A new method, i.e., heparin slow-release stent implantation combined with myocardium drilling, is discovered for myocardial revascularization, which remarkably improves myocardial perfusion. OBJECTIVE: To investigate the effect of heparin slow-release stent implantation combined with myocardium drilling on myocardial regeneration of pigs with acute myocardial infarction. METHODS: Anterior descending coronary of pig was ligated to induce myocardial infarction model, which was randomly divided into control and implantation groups, with 6 pigs for each group. Self-made borer was used in the implantation group to drill two transmural channels (3.5 mm diameter) on epicardium. A heparin slow-release stent was fixed in the transmural channel. Following intravenous injection, BrdU was used to label DNA duplication so as to observe stromal cell-derived factor-1 (SDF-1) mRNA expression, myocardial perfusion, newborn yocardium, and heart function prior to and following implantation. RESULTS AND CONCLUSION: As compared with control group, SDF-1 expression was enhanced in the implantation group at 6 weeks after stent implantation (P < 0.001), perfusion mass defect percentage was significantly decreased (P < 0.001), ejection fraction of left ventricle was increased (P < 0.05), newborn myocardium was increased (P < 0.001), and survival myocardium in the ischemic region was increased (P < 0.001). The results demonstrated that heparin slow-release stent implantation combined with myocardium drilling could repair damaged myocardial cells and improve heart function through increasing SDF-1 expression and myocardial perfusion. Related Articles | Metrics

Select

Effect of graphite carbon nanoparticles on cell growth in vitro Liu Dong-jing, Zhang Hong, Zhang Yang-de, Liu Mei-zhou, Wu Ji-lin, Pan Yi-feng, Chen Wei, Liu Hui, Zeng Qing-ren 2010, 14 (3):  443-446.  doi: 10.3969/j.issn.1673-8225.2010.03.015 Abstract ( 311 )   PDF (445KB) ( 527 )   Save BACKGROUND: Previous research has indicated that graphite carbon nanoparticles have a strong adsorbability. While, when the concentration is effectively controlled, graphite carbon nanoparticles also have well compatibility and sensitizing effect. OBJECTIVE: To observe the morphology of graphite carbon nanoparticles, and to investigate the effects of graphite carbon nanoparticles on cell proliferation and ultramicrostructure. METHODS: Graphite carbon nanoparticles (0.5 g) were put in 100 mL triple distilled water to obtain graphite carbon nanoparticle mother liquid after oscillation and microfiltration. HepG2 cells, L02 cells, Hl7702 cells, and 3T3 cells in the logarithmic phase were adjusted to the concentration of 5×107/L and inoculated in 6-well culture plate with 0.5 mL per well. Thereafter, the cells were cultured with RPMI-1640 culture media (1.5 mL) containing fetal bovine serum, penicillin, and streptomycin. The original culture solution was removed after 24 hours. The 1-5 wells were considered as the experimental group, and 25, 10, 7.5, 5, 0.25 mg/L graphite carbon nanoparticles (2.0 mL) were respectively added into each well; while, the sixth well was considered as the blank control group without graphite carbon nanoparticles. The cells in the blank control group were cultured for 24 hours. Particle diameter was measured using atomic force microscopy; morphology was observed using electron microscope; effect of different concentrations of graphite carbon nanoparticles on cell number was detected using hemacytometry under optic microscope; the effect of 7.5 mg/L graphite carbon nanoparticles on ultramicrostructure was observed under transmission electron microscope. RESULTS AND CONCLUSION: Graphite carbon nanoparticles were around and 20 nm diameter. Compared with the blank control group, cell numbers except HepG2 cells were increased, especially the effect of 7.5 mg/L graphite carbon nanoparticles was greatest (P < 0.05). Transmission electron microscope indicated that graphite carbon nanoparticles were distributed into cells, including cytoplasm, nucleus, and mitochondrion; while, subcellular structure damage and cell apoptosis and necrosis were absent. Graphite carbon nanoparticles have no side effects on in vitro cultured cells and can promote cell proliferation, showing a dose-dependence correlation, especially the concentration of 7.5 mg/L.　 Related Articles | Metrics

Select

Toxicity and biocompatibility of polyethylene glycol-polyethyleneimine/ferroso-ferric oxide nano-magnetic fluid Zou Fen, Pan Yi-feng, Zhang Hong, Li Guo-zheng, Tang Jing-bo, Peng Jian 2010, 14 (3):  447-451.  doi: 10.3969/j.issn.1673-8225.2010.03.016 Abstract ( 360 )   PDF (338KB) ( 689 )   Save BACKGROUND: Polyethylene glycol-polyethyleneimine/ferroso-ferric oxide (PEG-PEI/Fe3O4) was selected as drug carriers in tumor treatment, which can increase drug loading capacity and targeting capacity. OBJECTIVE: To test the toxicity of PEG-PEI/Fe3O4 nano-magnetic fluid in vitro and in vivo. METHODS: When the prepared PEG-PEI/Fe3O4 nano-magnetic fluid reached nano level, 7702 and HpG2 cell lines were filtrated and diluted in 5-20 multiple, and detected by in vitro MTT toxicity test assay; in vivo hemolysis test and micronucleus test was used to test the toxicity and biocompatibility. RESULTS AND CONCLUSION: MTT assay results indicated that the toxicity grade of PEG-PEI/Fe3O4 nano-magnetic fluid to 7702 cell line was 0-1, which was harmless to natural hepatic cells; however, PEG-PEI/Fe3O4 nano-magnetic fluid had slight bystander restraining effect to HpG2 cell line. Maximum hemolysis rate of the material was 0.372%, which was far less than 5%. The micronucleus test result indicated that PEG-PEI/Fe3O4 nano-magnetic fluid had no teratogenicity or mutagenicity. Related Articles | Metrics

Select

Preparation and releasing behavior of chitosan microspheres/nano-hydroxyapatite/PLGA scaffolds: Compared to nano-hydroxyapatite/PLGA scaffolds and chitosan microspheres Xu Yao-xiang, Li Ya-li, Chen Li-qiang, Yu Jia-you, Sun Jian 2010, 14 (3):  452-456.  doi: 10.3969/j.issn.1673-8225.2010.03.017 Abstract ( 286 )   PDF (630KB) ( 502 )   Save BACKGROUND: How to make growth factor plays a role persistently and efficiently is a key in constructing bone tissue engineered bone. Currently, varied microspheres or scaffolds were used as release carriers, however, the delayed release effects needs elevating. OBJECTIVE: To prepare chitosan microspheres/nano-hydroxyapatite/poly (lactic-co-glycolic acid) (CMs/nHA/PLGA) scaffolds, and to measure its characteristics of delayed release of bovine serum albumin (BSA). METHODS: CMs were prepared by an emulsifying cross linking method with BSA as a model protein. Using ice particulates as porogen, composite CMs/nHA/PLGA scaffolds were prepared by freeze-drying. The characteristic and morphology of the composite were observed by scanning electron microscope, later particle size analyzer, mercury porosimeter and universal testing machine, and the release behavior of BSA was investigated in vitro. RESULTS AND CONCLUSION: The CMs were spherical shape with a regular surface, with diameters of 20-40 μm. The encapsulation efficiency of the CMs was 86.5%, and the loading capacity was 0.8%. With the increase of initial BSA dosage, the loading capacity increased to 2.6%, while the encapsulation efficiency decreased to 74.1%. The CMs can be uniformly distributed in PLGA scaffolds to form CMs/nHA/PLGA scaffolds, which had 100-400 μm pore diameter and over 80% porosity, with 1.1-2.3 μMPa compressive strength, and 26.5% cumulative degradation at 10 weeks. The cumulative release of BSA from nHA/PLGA scaffolds was above 85% at 36 hours, which from CMs was 33.6% at 10 days, and that from CMs/nHA/PLGA scaffolds was 81.5% at 40 days. The results demonstrated that CMs/nHA/PLGA scaffolds have an excellent releasing efficiency for protein drugs with suitable compressive strength and degradation, which would be used as delivery system and tissue engineering scaffolds. Related Articles | Metrics

Select

Different surface treatments and bond strength of fiber posts: Differences among sandblasted, hydrogen peroxide and silaned treatments Xiong Ying, Chen Lei 2010, 14 (3):  457-460.  doi: 10.3969/j.issn.1673-8225.2010.03.018 Abstract ( 275 )   PDF (285KB) ( 569 )   Save BACKGROUND: Fiber posts are currently perceived as promising alternatives to cast metal posts, as their elastic modulus are similar to that of dentin, producing a favorable stress distribution and providing more esthetic outcomes for endodontically treated teeth. Failure of a fiber post and composite resin core often occurs at the junction between the two materials. This failure process requires better characterization. OBJECTIVE: To compare the bond strength of fiber posts after three surface treatments to a composite resin. METHODS: The coronal portions of 20 mandibular premolars with a single root canal were removed and were endodontically treated. After post space preparation, the roots were divided into four groups and the fiber posts and resin cores were lured. In the three testing groups, the surfaces of fiber posts were silaned, sandblasted or etched with hydrogen peroxide. In the control group, the surfaces of fiber posts were not treated. All specimens were exposed to cyclic loadings and thermal cycles. The roots were sectioned into slices with 1 mm thickness and their bond strengths were tested with a universal material testing machine. Test piece following testing was placed under optical microscope to observe the breakage method. RESULTS AND CONCLUSION: Stickiness strength was significantly greater in the sandblasted and hydrogen peroxide groups compared with the control group (P < 0.05). No significant difference in stickiness strength was determined between the sandblasted and hydrogen peroxide groups (P > 0.05). No significant difference in stickiness strength was detected between the silaned and control groups (P > 0.05). The splicing destruction among each group was the main breakage method between materials and fiber posts. The surface treatment of fiber posts with sandblast or hydrogen peroxide significantly enhanced the bond strength of the composite resin tested. The surface treatment of fiber posts with silane did not enhance the bond strength of the composite resin. Related Articles | Metrics

Select

Effect of different types of cements and the timing of tooth preparation on the coronal microleakage of fiber post Lei Hui-yun, Chen Lei, Xu Guo-fu,Liang Xiao-peng, Li Ji-jia 2010, 14 (3):  461-464.  doi: 10.3969/j.issn.1673-8225.2010.03.019 Abstract ( 315 )   PDF (318KB) ( 495 )   Save BACKGROUND: The vibration of high speed handpiece during tooth preparation may have adverse effect on the continuous force of the bonding interfaces among the cement, dentin, and post core. OBJECTIVE: To find the effect of different types of cements on the coronal microleakage of fiber post under different tooth preparation timings, and to provide evidence for the clinical operation. METHODS: The extracted mandibular premolars were divided into 3 groups, and they were cemented by Rely X luting, Panavia F and Paracore 5 mL, respectively. Each group was averagely divided into 3 subgroups: A, B, C groups which were prepared 15 minutes, 45 minutes, and 90 minutes after the cements mixed. All roots were then dyed and transparented. The teeth were observed under stereoscopic microscope and the dyeing scores were also recorded. RESULTS AND CONCLUSION: Rely X luting caused the highest coronal microleakage of fiber post, followed by Panavia F, while Paracore 5 mL brought about the lowest under the same tooth preparation timing. Different tooth preparation timing caused no significant effect on the coronal microleakage of fiber post when the cement had been completely set. Related Articles | Metrics

Select

Comparative study on three resin cements to restore anterior flared roots Liu Peng, Xie Qiu-fei 2010, 14 (3):  465-468.  doi: 10.3969/j.issn.1673-8225.2010.03.020 Abstract ( 348 )   PDF (448KB) ( 489 )   Save BACKGROUND: Fiber post is widely used in front teeth aesthetic repair, but some defect teeth cannot form ferrule or thick root canal, which resulted in fiber post prosthetic replacement defluxion and a failure of repair. Presently, new-style resin cement had self sticking component, showing good effects in sticking of fiber post. Whether combination of new-style resin cement can repair affected teeth using fiber post deserves further investigation. OBJECTIVE: Through fatigue test, residual flexural strength and scanning electron microscope (SEM) observation to compare the strength of severely weakened roots restored with three resin cements. METHODS: Eighteen intact maxillary central incisors were collected and formed to severely weakened canals at the same size. Three kinds of resin cements were used to restore. Rely X Unicem, Panavia F and Super-Bond C&B resin cement and identical glass fiber post were used. All the specimens were restored using Ni-Cr ceramic crown, and placed on TCML chewing machine that loaded 1 200 000 cycle forces, and the cycle times when failure occurred were recorded. The samples were intact following loading received residual flexural strength test. SEM was employed to observe breakage surface of the samples. RESULTS AND CONCLUSION: Mean cyclic loading was significantly greater in the Super-Bond C&B Group (1 200 000 times) than in the Relyx Unicem Group (640 000 times) and Panavia F Group (550 000 times) (P < 0.05). No significant difference was detected between the Rely X Unicem and Panavia F Groups. Residual flexural strength was 747.99 N in the Super-Bond C&B Group. SEM demonstrated that Super-Bond C&B formed longer resin processes, which were more than other two groups. Results confirmed that Super-Bond C&B demonstrated better results when restoring flared roots with prefabricated glass fiber posts. Related Articles | Metrics

Select

3M-Z350 Nano-resin and 3M-Z100 composite resin for cosmetic restoration of anterior teeth with vital pulp: Evaluation on postoperative sensitivity and pain Jiang Jun-qiang, Wang Zhong-chao, Jiang Jun, Cai Wei 2010, 14 (3):  469-472.  doi: 10.3969/j.issn.1673-8225.2010.03.021 Abstract ( 295 )   PDF (283KB) ( 648 )   Save BACKGROUND: Resin filling, full crown and veneer are used in cosmetic restoration of anterior teeth. Doctors prefer resin because of its perfect clinical effect and small hurt. Some patients complain of sensitivity after rsein filling and we are interest in choosing a better resin with less sensitivity. OBJECTIVE: To compare the incidence of postoperative sensitivity and the difference of the patients’ self sensitivity after cosmetic restoration of anterior teeth with vital pulp by 3M-Z350 Nano-resin and 3M-Z100 composite resin.  METHODS: A total of 112 teeth with vital pulp because of caries or traumatic tooth fractures of 68 patients demanding cosmetic restoration were selected from the Department of Endodontics, Stomatological Hospital of Luzhou Medical College from August to December 2006. The teeth were random divided into 3M-Z350 group and 3M-Z100 group, with 56 teeth in each group. 3M-Z350 nano-resin and 3M-Z100 composite resin were used for cosmetic restoration of anterior teeth with vital pulp. Ryge criteria were used to evaluate the sensitivity to the cold stimulation following cosmetic restoration, and the level of pain was detected by the pain ruler. RESULTS AND CONCLUSION: Compared with 3M-Z100 group, the incidence of sensitivity and self-pain level were decreased in the 3M-Z350 group at 1 day, 1 week, and 1 month after restoration (P < 0.01 or P < 0.05). There was no significant difference in the sensitivity and self-pain level between the two groups (P > 0.05). Anterior teeth with vital pulp were well restored by 3M-Z350 nano-resin which might reduce the incidence of postoperative sensitivity.　 Related Articles | Metrics

Select

The kinetics of in vitro lysozyme deposition on rigid gas-permeable contact lens for a short period Zhang Jin, Wan Zi-yi, Nan Kai-hui, Zheng Qi, Qu Jia, Xi Ting-fei 2010, 14 (3):  473-476.  doi: 10.3969/j.issn.1673-8225.2010.03.022 Abstract ( 344 )   PDF (333KB) ( 483 )   Save BACKGROUND: The contact lenses were easily contaminated by adsorbing components from the tear film, particularly protein after wearing for a period of time. Lysozyme adsorption dynamics of ?uorosilicone acrylate contact lenses has been studied in order to further improve data of protein adsorption, reduce adsorbing amount of surface protein, and prevent surface contamination of contact lenses. OBJECTIVE: To investigate the adsorption dynamics of ?uorosilicone acrylate contact lenses to lysozyme in vitro. METHODS: A stock solution of lysozyme was prepared in Hanks balanced salt solution (2.0 g/L, solution I) and different trifluoroacetic acid (TFA) concentrations were prepared. Recovery experiment, the contact lenses were placed in shaking incubator at 37 ℃ for varying time intervals. After incubation there was a single rinsing in Hanks balanced salt solution. Contact lenses in control group were placed in diluted water, and contact lenses in the other group were placed in different concentrations of TFA. For deposition, FSA contact lenses in experimental group were placed in shaking incubator at 37 ℃ for varying time intervals. After incubation there was a single rinsing in Hanks balanced salt solution. Then FSA contact lenses were immersed in 0.2% TFA solution. The amount of lysozyme was assayed with BCA method. RESULTS AND CONCLUSION: Lysozyme which attached to ?uorosilicone acrylate contact lenses could be resolved by TFA, and the recovery was influenced by the immersed time and the concentration of TFA. The optimal time was 1 hour, and the optimum concentration was 0.2%. The adsorption dynamics of lysozyme on FSA contact lenses was a second-phased process, i.e., lysozyme adsorption increased rapidly during 10 minutes-1 hour, reached a plateau at 1 hour, stably adsorbed during 1-24 hours, and reached a saturation of 0.349 mg/cm2. The recovery of lysozyme was lower at 10 and 30 minutes, but reached 90%-100% while the time of incubation was between 40 minutes and 24 hours. Related Articles | Metrics

Select

Preparation of chitosan/polyvinyl alcohol composite scaffold at different mass ratios: Comparison of structure and characteristics Li Qin-hua, Huang Lei, Li Hui, Fang Si-han 2010, 14 (3):  477-481.  doi: 10.3969/j.issn.1673-8225.2010.03.023 Abstract ( 252 )   PDF (980KB) ( 584 )   Save BACKGROUND: Polyvinyl alcohol (PVA) has similar water content as human tissues, good biocompatibility and high mechanical strength, thereby being utilized as tissue-engineered matrix material. However, the modification in cellular affinity benefits the function as tissue regeneration scaffold materials. OBJECTIVE: To prepare chitosan (CS) / PVA composite scaffold and explore the feasibility of serving as a scaffold for tissue engineering. METHODS: Scaffolds of CS/PVA was fabricated by blending PVA-124 with various amounts of CS using film forming, particle forming, and free-drying methods. Water content, light transmittance, and swelling ratio were tested. Scanning electron microscope was used to observe the configuration of the cross section. RESULTS AND CONCLUSION: A total of 7 different proportional scaffolds were obtained with different PVA and CS dosage. The composite film showed light transmittance between 70%-80%, high water content between 121.2%-162.5% and swelling ratio between 60.3%-133.7%.Composite particle and sponge obtained water content between 82.0%-461.2% and 280.8%- 1 939.0%. Composite scaffold with the amount ratio of PVA 0.75 g/CS 0.15 g exhibited the best performance. Scanning electron microscope showed that at a mass ratio of PVA 0.75 g/CS 0.15 g, the scaffold prepared by freeze-drying method had regular, fluffy inner structure, with good mechanics and high water content. Related Articles | Metrics

Select

Poly N-isopropylacrylamide grafted tissue culture polystyrene dish for controlling cell detachment based on temperature changes Liu Jing-ping, Zhang Lan-lan, Zhao Xiao-jun 2010, 14 (3):  484-487.  doi: 10.3969/j.issn.1673-8225.2010.03.025 Abstract ( 298 )   PDF (344KB) ( 476 )   Save BACKGROUND: In the tissue engineering studies, the common method of cell detachment is trypsinization. However, this method may decrease cell activity by breaking the extracellular matrix proteins. Therefore, it is important to develop a new cell detachment method which can avoid the damage from trypsinization. OBJECTIVE: Based on that poly N-isopropylacrylamide (PNIPAAm) could alter its hydrophobic property with the change of temperature, this study aimed to develop a novel method which can control cell detachment by simply changing the temperature. METHODS: IPAAm was dissolved in isopropanol with final concentration of 55% (w/v). IPAAm solution was evenly laid on the surface of TCPS dish, and PNIPAAm was then covalently grafted on the TCPS dish surface by electron beam irradiation. The microstructure of the surface of TCPS dish was observed by atomic force microscopy (AFM) before and after PNIPAAm grafted. Water contact angle was determined by sessile drop method. And an inverted phase contrast microscope was used to observe and evaluate the cell detachment ability of PNIPAAm grafted TCPS dish by subjecting the same dish to different temperatures. RESULTS AND CONCLUSION: AFM images showed that a thin and compact PNIPAAm layer formed on the TCPS dish surface. In the water contact angle test, there was no statistic difference between PNIPAAm grafted and ungrafted surfaces at 37 ℃, and the water contact angle of PNIPAAm grafted surfaces was lower than that of ungrafted surface at 20 ℃. The cells adhered to the surface of the PNIPAAm grafted TCPS dish at 37 ℃, which would be detached at 20 ℃.It was successful to control cell detachment by simply changing the temperature with PNIPAAm grafted TCPS dish, and it would be promising to be applied in tissue engineering. Related Articles | Metrics

Select

Clinical application of acellular biological dressing in burn wound: Outcomes of 106 patients with 150 wounds Li Hua-qiang 2010, 14 (3):  488-491.  doi: 10.3969/j.issn.1673-8225.2010.03.026 Abstract ( 324 )   PDF (336KB) ( 455 )   Save OBJECTIVE: To evaluate the application of different types of wound dressing acellular biological effect. METHODS: The acellular biological dressing was used in the 106 cases of 150 burn wounds. There were 84 donor site wounds, 30 Ⅱ degree superficial and 16 deep Ⅱ degree of fresh wounds, 10 Ⅲ degree burn wounds, 5 surgical wounds in the lack of space in autologous skin grafting, and 5 latter part of the small residual wounds. Acellular biological dressing with the covering of dry gauze bandage was used immediately after the surgery to take skin, debridement, and dermoplasty clearance separately. RESULTS: Among 150 wounds, 4 non-adherent wounds (2.67%) were Ⅲ degree wounds. Infected 2 wounds (1.3%) were latter part of the small residual wounds. Significant accumulation of exudation required 4 (2.67%) deep Ⅱ degree fresh wounds. Other wounds presented good adherence, no infection, less capillary hemorrhage, and significant relief of pain. CONCLUSION: The acellular biological dressing for skin graft donor site wounds, superficial and deep Ⅱdegree fresh wounds, wounds with autologous skin grafting gap results were satisfactory. Related Articles | Metrics

Select

Changes of corneal endothelial cells after Ahmed glaucoma valve implantation Li Ke-yan, Xu Shao-lin, Liu Dan, Wang Ying 2010, 14 (3):  492-495.  doi: 10.3969/j.issn.1673-8225.2010.03.027 Abstract ( 325 )   PDF (316KB) ( 398 )   Save BACKGROUND: Ahmed glaucoma valve (AGV) is usually implanted at the superotemporal area of eyes. Corneal endothelial cells cannot regenerate, so the repair of the endothelial cells mainly depend on the extension and progradation of the healthy cells in other area. Therefore, changes of density and shape are observed in the corneal endothelial cells after AGV implantation. OBJECTIVE: To observe the changes of density and morphology of corneal endothelial cells after AGV implantation. METHODS: Ahmed glaucoma valves were implanted in 34 eyes of 34 patients with refractory glaucoma. Density and morphology of corneal endothelial cells were evaluated in the superotemporal, superonasal, infratemporal, infranasal, and central corneal areas to calculate mean value of total cornea before and at 3 and 6 months after surgery. Percentage of hexagonal cells was statistically summarized. 　 RESULTS AND CONCLUSION: Mean density of corneal endothelial cells was statistically decreased following AGV implantation (P < 0.05), In particular, the decrease was obvious in the superotemporal area. Density of corneal endothelial cells was not changed in central area before and after AGV implantation. Morphological changes demonstrated that hexagonal cells were increased, but polygon cells were increased (P < 0.05). Density of corneal endothelial cells was gradually decreased, and morphology was also changed at 6 months after AGV implantation, suggesting that more care should be taken during intra-operation in order to minimize damage to the endothelium and prolong monitoring time of corneal endothelial cells following AGV implantation. 　 Related Articles | Metrics

Select

Partial crown with aperture of neighboring surface repairs the fixed bridge of porcelain-fused-to-metal with cracking of porcelain Liu Yang, Ying Xiao-xia 2010, 14 (3):  496-499.  doi: 10.3969/j.issn.1673-8225.2010.03.028 Abstract ( 318 )   PDF (479KB) ( 453 )   Save BACKGROUND: Ceramic crown porcelain fracture is wide in clinic. The method of repairing single crown porcelain fracture is simple and effective, but it is difficult for ceramic fixed bridge, especially individual teeth porcelain fracture on the long bridge. There is no report concerning prosthesis of partial crown with aperture of neighboring surface. OBJECTIVE: To lessen suffering and economic burden of the patient with cracking of porcelain on the fixed bridge, to decrease the chanciness and manufacture procedure of removing the porcelain fixed bridge, to discuss the feasibility of prosthesis of partial crown with aperture of neighouring surface. METHODS: By preparing tooth at damaged pontic or retainer of the porcelain fixed bridge in oral, shaping “core” retention form which analogy “keyway” form at both of retainers, and then make the porcelain partial crown with aperture of neighboring surface. RESULTS AND CONCLUSION: We followed up 27 patients that porcelain-fused-to-metal (PFM) with cracking of porcelain using partial crown with aperture of neighboring surface to repairing for 2-3 years. The prosthesis was strong; the edge of prosthesis was close together, without exposing metal or cracking of porcelain, gingival had no redness at the edge of crown and pontic. Patients feel good, chewing was normal. These suggested that the prosthesis of partial crown with aperture of neighboring surface is an effective method for restoring the fixed bridge with cracking of porcelain, with less risk, low cost and simple operation. Related Articles | Metrics

Select

Preparation and development of nano-hydroxyapatite/chotisan composites Guo En-yan, Wang Feng, Zhao Ping, Chu Xin-hong, Jiang Qian 2010, 14 (3):  500-504.  doi: 10.3969/j.issn.1673-8225.2010.03.029 Abstract ( 331 )   PDF (368KB) ( 905 )   Save BACKGROUND: Nano-hydroxyapatite has been widely used as reconstructive and prosthetic material for osseous tissue, owing to its excellent biocompatibility and bioactivity. But, its brittleness is one of the most serious obstacles for its wider applications as load-bearing implants. Therefore, hydroxyapatite/chitosan composites have been widely studied as bone substitute, due to their excellent biocompatibility and suitable mechanical properties. OBJECTIVE: To review various preparation methods of hydroxya patite/chitosan composites and the development trend in this field. METHODS: Articles were searched in Medline Database (1995-01/2009-03), VIP Database (1995-01/2009-03) and “qinghuatongfang” Database (1995-01/2009-03) with the keywords of "nano-hydroxyapatite, chitosan, preparation, development trend". RESULTS AND CONCLUSION: Total 2 034 related articles were collected, including 1 634 in Chinese and 670 in English. Following excluding earlier published, duplicate, and similar studies, we brought into 37 sub-standard literatures. Hydroxyapatite/chitosan composite in nanometer size, with similar structure as natural bone, has better biological function compared with corresponding micrometer composite. Simultaneously, optimized material composition, structure and technology will obtain more suitable bone substitute in mechanical property compared with natural bone. This paper reviews preparation methods at home and abroad in recent years, with the rapid development of biological materials, hydroxyapatite composite materials have been wisely used in bone tissue repair and replacement surgery, but its poor mechanical properties limits its clinical application. Related Articles | Metrics

Select

Theoretical research and progress of basal body and bio-coatings in biomaterial field Wang Wen-jing, Huang Jian-feng, Li Ying-hua, Cao Li-yun 2010, 14 (3):  505-508.  doi: 10.3969/j.issn.1673-8225.2010.03.030 Abstract ( 373 )   PDF (294KB) ( 540 )   Save BACKGROUND: In the research of biomaterial, especially bio-coatings field, how to find a good biological and mechanical properties basal body, and to prepare coatings with uniform and compact surface and strong bonding force, is the key factor in clinical Application of artificial prosthesis. OBJECTIVE: To review the progress of bio-coatings. METHODS: Databases of CNKI, VIP, and Science Direct were retrieved with key words of “Biocoatings, HAp, Titanium, Carbon/carbon composites” to search pApers published from January 1998 to October 2009. PApers underlying bio-coatings were selected. Totally 216 literatures were initial searched, according to inclusive criteria, 31 literature were summarized.  RESULTS AND CONCLUSION: By contrasting the basal bodies made of titanium or carbon/carbon and different coating preparation, we found that the basal body composed of carbon/carbon composites exhibited good biocompatibility, which had similar strength to natural bone. Using hydrothermal method, the composites coating prepared by taking carbon/carbon as basal body and hydroxyApatite, chitosan, or polymethyl methacrylate as coatings provided a new idea for increasing the combing strength between coatings and basal body. Related Articles | Metrics

Select

Effect of microelement on the bioactivity of micro-arc oxidation ceramic coating on Ti-based implant Wang Jian-ping, Li Xing-hai, Meng Xiang-cai, Liu Jie, Wang Jing, Lu Yan-ping 2010, 14 (3):  509-512.  doi: 10.3969/j.issn.1673-8225.2010.03.031 Abstract ( 326 )   PDF (301KB) ( 582 )   Save BACKGROUND: Micro-arc oxidation, also be known as micro-plasma oxidation or anodic spark deposition, is a new technology that can in situ grow ceramic coating directly on the surface of non-ferrous metals. And the ceramic coating has such characteristics as high corrosion resistance, good wear resistance, etc. It is advantageous to the osseointegration between implant and bone that the ceramic coating is able to produce porous, rough oxide film on the surface layer of the implant, which improves the biological reaction of the bone interface so as to affect the number of bone-forming cells, type, products of cell, and the expression of the product. OBJECTIVE: To observe the osseointegration between bone and implant, and to analyze induced action of metal trace elements to bone-formation’s marker (ALP). METHODS: A computer-based online search was conducted in PUMMED and Chinese Journal Full-text Database with the key words of “micro-arc oxidation, synosteosis, titanium, magnesium” in both English and Chinese between 1995 and 2009. Additionally, hand-made retrieval was performed for articles about micro-arc oxidation and microelement. Among 96 articles, 34 references were excluded due to unrelated and duplicated articles, and 28 ones were excluded due to long-term publication, 34 ones were included in the final analysis. RESULTS AND CONCLUSION: It is believed that the surface modification methods on microelement and micro-arc oxidation ceramic coating on Ti-based implant will become the mainstream process to improve the rate of implant-bone integration. However, the clinical application still needs to be further studied. Related Articles | Metrics

Select

Research status of superparamagnetic iron oxide MR contrast agent: Marking features, safety and limitation Dai Yi, Wu Yuan-kui 2010, 14 (3):  513-516.  doi: 10.3969/j.issn.1673-8225.2010.03.032 Abstract ( 360 )   PDF (340KB) ( 368 )   Save BACKGROUND: Superparamagnetic iron oxide (SPIO) contrast agent has been extensively explore in tracing imaging following stem cell transplantation, arabinogalactan cell membrane receptor targeted imaging, as well as liposome-coated SPIO. OBJECTIVE: To summarize the research state of liposome-coated SPIO. METHODS: A computer-based online search of CNKI and Science Direct (1998-01/2009-09) was performed to search the articles about liposome-coated SPIO with key words “SPIO, superparamagnetic iron oxide, liposome, MR contrast agent” in Chinese and English. Articles related to MR contrast agent, and published in recently or authorial journals of the same field were included. A total of 48 articles were collected, and 24 articles and 1 composition related to liposome-coated SPIO were reviewed. RESULTS AND CONCLUSION: The incessant innovation in MR contrast agents can greatly improve the diagnosis of MRI. Due to the good performances, diagnostic value of SPIO in many diseases has surpassed previous MR contrast agents. Liposome-coated SPIO has the merits of low toxic side effect, and well targeting in specific tissues, thereby extensively being used in experimental studies and clinical application. With the development of functional imaging and molecular imaging, the use of liposome-coated SPIO must be more extensive. Related Articles | Metrics

Select

Renal toxicity of dental porcelain crown containing Ni-Cr alloy: Theoretical study and clinical verification Fan Can-can, Ning Jing, Meng Song, Li Ying-long, Peng Peng, Liu Bin 2010, 14 (3):  517-520.  doi: 10.3969/j.issn.1673-8225.2010.03.033 Abstract ( 383 )   PDF (356KB) ( 777 )   Save BACKGROUND: Dental porcelain crown containing Ni-Cr alloy has been widely used in modern dentistry. The dispute of its safety is limited in oral cavity and neighbor tissues, however, the relevance between Ni-Cr alloy and systemic disease, such as nephridium toxicosis, are poorly understood. OBJECTIVE: To analyze the possibility of Ni-Cr porcelain crown resulted nephropathy and to explore its long-term clinical safety. METHODS: Databases of VIP, CNKI, Wanfang, CBMdisc, Biosis Previews and BioOne were researched by computer with key words of “nickle chromium alloy, porcelain crown, nephridium toxicosis” both in Chinese and English. Literatures concerning Ni-Cr porcelain crown and toxicity of related metal ion were included, repetitive research was excluded. RESULTS AND CONCLUSION: By consulting literatures, the possibility of erosion and release of heavy metal ion lead to nephridium toxicosis were analyzed with following aspects: effects of Ni-Cr alloy corrosivity and its accumulation on oral cavity or systemic disease; direct toxicity of released metal ions from Ni-Cr alloy and susceptivity of nephridium toxicosis; and the possible ways for renal damage resulted by Ni-Cr ion. This study can provide a basis for the further research concerning security of dental porcelain crown containing Ni-Cr alloy. Related Articles | Metrics

Select

Recent research and progress of medical dressings Ke Lin-nan, Feng Xiao-ming, Wang Chun-ren 2010, 14 (3):  521-524.  doi: 10.3969/j.issn.1673-8225.2010.03.034 Abstract ( 434 )   PDF (353KB) ( 1305 )   Save BACKGROUND: Medical dressings can play a temporality barrier function as skin substitute in wound healing, which can avoid or control wound infection. With the increasing of aging and chronic ulcer wound, medical dressings play a more important role. OBJECTIVE: To review the recent research and progress of medical dressings, in addition, to explore its developing direction. METHODS: Elsevier database and CNKI was retrieved by computer with key words of “medical dressing, collagen, gel and chitosan” to search papers published between January 1980 and January 2009. Related papers addressing medical dressings were selected. According to inclusion criteria, 35 literatures were selected in this study. RESULTS AND CONCLUSION: Currently, the medical dressings can be classified into natural polymer, synthetic macromolecule, inorganic material and composite. Their performances and clinical application were reviewed respectively. The quality control and future development of medical dressing products were also discussed. This paper can provide a theoretical foundation for the researcher in study and development of medical dressings, manufacturer in the quality control and government in product quality supervision. Related Articles | Metrics

Select

Biological characteristics of tendon and performance evaluation of repair materials for tendon defects Li Xiu-fen, Wang Hong-dong, Li Li 2010, 14 (3):  525-528.  doi: 10.3969/j.issn.1673-8225.2010.03.035 Abstract ( 324 )   PDF (306KB) ( 440 )   Save OBJECTIVE: To explore the biological characteristics of tendon and performance of repair materials for tendon defects. METHODS: CNKI and Medline database were retrieved by computer for papers published between 1985 and 2009. Literature concerning biological characteristics and performance of repair materials for tendon defects were selected. Meta analysis, irrespective papers or repetitiveness studies were excluded. Totally 29 papers were included after screening and evaluating including 16 in Chinese and 13 in English. The biological characteristics of tendon and performance of repair materials were summarized. RESULTS: Nutrition for tendon mainly supplied by blood, and the tendon fatigue would be occurred with repeatability loads. Compared to other tissue-engineered materials, tendon possesses self-repair ability. The biological characteristics of tendon was closely associated with collagen fiber, which exhibited similar stress-strain curves, namely, characteristics of viscoelasticity body—hysteresis, creep and stress relaxation. Currently, main repair materials for tendon defects comprised autogenous tendons, allogeneic tendon, artificial tendon and tissue engineered tendon. CONCLUSION: Many materials can be used in tendon repair with distinct advantage and disadvantage; however, there is not an ideal repair method. With the development of tissue and gene engineering, the optimal substitute for tendon would be prepared.  Related Articles | Metrics

Select

Application of biological patch in pelvic restoration and reconstruction Xiao Fan 2010, 14 (3):  529-532.  doi: 10.3969/j.issn.1673-8225.2010.03.036 Abstract ( 295 )   PDF (348KB) ( 529 )   Save BACKGROUND: Understanding of patch classification, characteristics, and reaction with host is necessary for best selection of reparative surgery materials. OBJECTIVE: To summarize the patch classification, characteristics and its application in pelvic reconstruction, as well as the complications. METHODS: A computer-based online search of PubMed database (http://www.ncbi.nlm.nih.gov/PubMed) and CNKI database (www.cnki.net/index.htm) was performed for related articles with the key words “patch, polypropylene, compound patch” in Chinese and “reconstructive pelvic surgery, repair, replacement” in English. Articles regarding patch classification, characteristics, biocompatibility, and application effect, or in the same circle published recently in authoritative journals were included. A total of 24 articles were finally selected.    RESULTS AND CONCLUSION: Polypropylene patch is weaved network, with large mesh, which allows for fiber tissue ingrowth and improves tissue intensity and tensile strength. Leukocyte and macrophage can enter the mesh, so the patch has good anti-infection ability. Expanded polytetrafluoroethylene is soft and smooth, with good tissue tolerance, and can prevent affixion with intraabdominal tissues. Moreover, the submicron pore diameter prevents bacteria invasion. The inflammation and foreign body reaction induced by the expanded polytetrafluoroethylene is the most slight among artificial synthetic materials. Related Articles | Metrics

Select

Clinical application of alginate dressing: A comparison with traditional materials Wang Qing-hua, Zhong Wen-fei, He Men 2010, 14 (3):  533-536.  doi: 10.3969/j.issn.1673-8225.2010.03.037 Abstract ( 480 )   PDF (304KB) ( 1153 )   Save OBJECTIVE: To explore the characteristics and clinical application of alginate dressing to provide better biological dressing for clinical wound healing. METHODS: A computer-based online search of CNKI, Medline, Wanfang, Science Direct, and Ei databases was performed for related articles published between January 1960 and October 2009, with the key words “alginate, dressing, clinical application” in Chinese and English. Studies regarding characteristics and clinical application of alginate dressing were included. Repetitive and Meta analysis were excluded. In addition, related books were manually searched. RESULTS: A total of 65 articles were collected, 17 were included, and 48 repetitive or Meta analyses were excluded. Alginate is natural polysaccharide carbohydrate extracted from sea tangle, and alginate dressing is soft non-textile fiber refined from seaweed. It contains 85% natural alginate fiber and 15% sodium tvlose. It can absorb effusion, form gelate, and exchange Na+ /Ca 2+ with effusion. Alginate dressing has been widely used in bedsore treatment, anal fistula nursing, stoma nursing, and diabetic foot nursing. Compared with traditional dressing, infection rate of alginate dressing is lower due to good impermeability, promotion of regional vessel proliferation and blood supply, as well as moist and slightly acidic environment which benefits neutrophil function enhances disinfection. Moreover, it can be used in wound healing following abdominal region operation and abscess incision drainage. CONCLUSION: Alginate dressing provides appropriate environment for wound growth, retains active materials in diffusion, promotes active material release, benefit necrotic tissue solution and cell proliferation and differentiation, as well as epithelial cell migration. Moreover, it maintains hypoxia state of wound, stimulates newly generated capillary growth, and promotes granulation tissue growth. Related Articles | Metrics

Select

Application of colorized polymethyl methacrylate intraocular lens in trigeminal operations of cataract extraction and corneal transplantation Wu Yi, Gu Ai-ping, Xia Zhao-xia 2010, 14 (3):  537-540.  doi: 10.3969/j.issn.1673-8225.2010.03.038 Abstract ( 297 )   PDF (320KB) ( 558 )   Save OBJECTIVE: Intraocular lens are applied in trigeminal operations of cataract extraction and corneal transplantation, and the selection of artificial lens is modified. This paper evaluated the application of colorized polymethyl methacrylate (PMMA) intraocular lens in interlaced non-phacoemulsification cataract extraction with intraocular lens implantation and keratoplasty (trigeminal operation). METHODS: A computer-based online search of CNKI (2003/2007) and Medline database (1974/2004) was performed for related articles with the key words “colorized intraocular lens, corneal transplantation, cataract, combination operation” in Chinese and “PMMA intraocular lens, cataract extraction, corneal transplantation” in English. Articles related to PMMA intraocular lens in cataract and corneal transplantation trigeminal operation was selected. Meta analysis and repetitive articles were excluded. A total of 11 articles were included and summarized. RESULTS: A total of 21 cases (21 eyes) of corneal leukoma and cataract caused by various trauma or ophthalmopathy underwent colorized PMMA intraocular lens implantation. During the follow-up for 10 months, visual acuities of naked eyes in 92% cases were significantly improved. Two weeks after operations, visual acuities of 9 cases (42.9%) were over 4.7, 10 cases over 4.5, and 2 cases (9.5%) over 4.0. At days 7 to 14 after operation, corneal grafts of 21 cases were completely transparent; 10 months after operation, corneal grafts of 16 cases were completely transparent, 3 cases were semitransparent, and 2 cases were turbid, who underwent second penetrable corneal transplantation. CONCLUSION: The application of colorized PMMA intraocular lens in penetrable corneal transplantation combined cataract extraction can cure the refracting media turbidity of forepart eye. Compared with traditional operations, trigeminal operation reduces complications, increases safety and improves visual acuity. Related Articles | Metrics

Select

Bioreactor in bioartificial liver system Xu Dong, Fu Wen-jun 2010, 14 (3):  545-548.  doi: 10.3969/j.issn.1673-8225.2010.03.040 Abstract ( 320 )   PDF (307KB) ( 603 )   Save OBJECTIVE: To introduce the basic functions, working conditions and requirements of bioreactor, additional, to discuss the research process of bioreactor. METHODS: PubMed database (http://www.ncbi.nlm.nih.) and CNKI database (www.cnki.net/index.htm) were retrieved by the first author with search terms of “bioartificial liver, bioreactor, membrane material” both in English and Chinese. The time was limited between January 1994 and August 2009. Inclusion criteria: ①literatures closely linked to the article; ②papers published in more authoritative journals in recent years. ③the contents of old or duplicate documents were excluded. RESULTS: Totally 150 documents were seized by primary screen, 88 irrelative papers and 32 duplicate documents were excluded, finally, 30 literature entered further analysis. Bioartificial liver system has become an effective in vitro supportive treatment for hepatic failure patients. Bioreactor is an important ingredient of bioartificial liver, which provided a platform for the hepatocytes growth metabolism, substances exchange and immune isolation. The main cellulose semipermeable bioreactor comprises flat membrane bioreactor and hollow fiber bioreactor, and the main types of semipermeable membranes contain mixed cellulose ester membrane, cellulose acetate membrane, cuprophan membrane, PVDF membrane, as well as poly(ethylene terephthalate) membrane. CONCLUSION: As a dynamic system, the optimal of control system in bioreactor is conductive to regulating mass transfer and establishing bionic physical or chemical gradients, which can implement the construction of hepatocyte with smallest unit. The selection of membrane is the key link in bioreactor construction of bioartificial liver system Related Articles | Metrics

Select

Physio-chemical progress and clinical application of microencapsulated hepatocytes Wang Jia-xiang, Han Bao-san, Wu Xu-bo, Yu Song-lin, Huang Fang, Kuang Jie, Peng Cheng-hong 2010, 14 (3):  549-551.  doi: 10.3969/j.issn.1673-8225.2010.03.041 Abstract ( 282 )   PDF (292KB) ( 782 )   Save With the development of cell separation technique, hepatocyte transplantation becomes a hot topic; however, the application is limited by donor deficiency and immunological rejection. Microencapsulated hepatocytes contribute to the promotion and application for liver cell transplantation, for which provide a large amount of high activity and good function of liver cells. In this paper, liver cell microencapsulation technology and its progress in applications were reviewed, providing prospective way for large-scale and high-active culture in vitro and long-term cryopreservation. Related Articles | Metrics

Select

Investigation on methods of surface modification of tissue engineering materials Polymer surface group transformation and bioactive molecule immobilization Chen Bao-lin, Wang Dong-an, Feng Lin-xian 2010, 14 (3):  552-554.  doi: 10.3969/j.issn.1673-8225.2010.03.042 Abstract ( 310 )   PDF (140KB) ( 790 )   Save This paper aimed to present the surface modification of tissue engineering materials and its correlation with cell compatibility from the aspects of cell-compatibility polymer surface group transformation and bioactive molecule immobilization. Related Articles | Metrics

Select

Complex of dog allogenic decalcified bone matrix and bone marrow stromal cell sheets In vitro culture and observation Tan Shuai, Jing Heng, Gao Zhen-hua, Li Ning-yi 2010, 14 (3):  555-558.  doi: 10.3969/j.issn.1673-8225.2010.03.043 Abstract ( 236 )   PDF (360KB) ( 528 )   Save BACKGROUND: How to reconstruct tissue-engineered bone with structure similar to natural bone is a problem in the development of tissue engineering. Cell sheet engineering technology enables novel approaches to construction of tissue-engineered bone. OBJECTIVE: To observe the biocompatibility of cell sheets to decalcified bone matrix (DBM) and their growth on DBM. DESIGN, TIME AND SETTING: An in vitro observation was performed at the Central Laboratory, Affiliated Hospital, Qingdao University Medical College between June and September 2009. MATERIALS: Dog bone marrow stromal cell sheets were prepared using temperature-responsive medium. Dog DBM was prepared by defatting, decalcification, and noncollagen protein removal procedures. METHODS: DBM surface was covered by cell sheets prepared by temperature-responsive technology and cultured with DMEM containing 10% fetal bovine serum and osteoinductive agent. MAIN OUTCOME MEASURES: Under scanning electron microscope, DBM structure, as well as the attachment and growth of cell sheets on DBM surface, was observed. Porosity and aperture size of DBM were calculated. RESULTS: DBM exhibited a three-dimensional latticed structure, with a porosity of approximately 75%. The mean aperture size was (250.11±98.89) µm, exhibiting a normal distribution. Cell sheets well attached to and grew on DBM surface, and rapidly proliferated. CONCLUSION: Cell sheets show good biocompatibility to DBM. DBM/cell sheets complex can be applied in tissue-engineered bones, which promotes the construction of tissue-engineered bone with structure similar to natural bone. Related Articles | Metrics

Select

Histocompatibility of poly (lactic-co-glycolic acid)/RNA Ⅲ inhibiting peptide sustained release microspheres Li Jing-dong, Zhang Xiao-bin, Hao Li-Bo, Xing Qing-chang, Wang Ji-fang 2010, 14 (3):  559-562.  doi: 10.3969/j.issn.1673-8225.2010.03.044 Abstract ( 357 )   PDF (225KB) ( 445 )   Save OBJECTIVE: To evaluate the histocompatibility of poly (lactic-co-glycolic acid)/RNA III inhibiting peptide (PLGA/RIP) sustained release microspheres.  METHODS: The crude peptide comprising N to C-terminals was synthesized using Fmoc method. The crude synthetic RNAIII peptide was purified by reverse phase high performance liquid chromatography, followed by component harvesting according to ultraviolet absorption peak, and freeze-drying. PLGA/RIP sustained release microspheres with a diameter of 50-70 μm were prepared using liquid-phase multiple emulsion method. The histocompatibility of PLGA/RIP sustained release microscopes were preliminarily evaluated through the use of acute general toxicity test, MTT cytotoxicity test, intramuscular implantation test, sensitivity test, and pyrogen test. RESULTS: Acute general toxicity test results showed that all included animals survived and presented with no toxicosis reaction and obviously changed body mass. MTT cytotoxicity test results revealed that the average relative growth rate of cells from two eluents was over 85%, with cytotoxicity grade 1, which indicates no cytotoxicity. Intramuscular implantation tests showed that at 4 weeks after implantation of RIP powder or PLGA/RIP microscopes, no obviously congested, degenerated, or necrotic tissue was observed. All RIP powder and a part PLGA/RIP microscopes were degraded. Fibroblasts accounted for a large proportion in all cells. No inflammatory cell infiltration, involving neutrophils and multinucleated giant cells, was observed. Sensitivity test results displayed that the average primary irritation index was 0.38, 0.33, and 0.31 in the eluent stock solution, 2% dinitoflruorobenzene, and physiological saline-administerd groups, respectively. Pyrogen test results showed that fervescence of each rabbit in the experiment was under 0.5 ℃ and the sum of fervescence was under 1.3 ℃.This is in coincidence with evaluation criteria of pyrogen test. CONCLUSION: PLGA/RIP sustained release microspheres exhibit good histocompatibility. Related Articles | Metrics

Select

Biocompatibility of silk scaffold/3T3-L1 preadipocytes compounds An in vitro experiment Liu Xiu-hua 2010, 14 (3):  563-566.  doi: 10.3969/j.issn.1673-8225.2010.03.045 Abstract ( 213 )   PDF (274KB) ( 567 )   Save BACKGROUND: Silk, a natural product, has been paid wide attention in medical field owing to a fact that silk’s mechanical property and biocompatibility are superior to traditional artificially synthesized degradable polymers. OBJECTIVE: To observe the effects of silk on the adsorption as well as cell morphology and function of 3T3-L1 preadipocytes. METHODS: Raw silk and trypsin-digested silk were ad libitum twisted into reticular fibrous cord with three-dimensional structure: mesh size 70-200 μm, thickness 200-300 μm, and porosity 20%. The three-dimensional scaffolds made of digested silk were placed in the 24-well plate. 3T3-L1 preadipocytes suspension (6×1010/L) was added to the culture plate, 3 drops comprising 1×107 cells per well. Following 4-hour incubation in the air, when cells fully attached to the scaffold, they were thoroughly soaked with medium, which was renewed every other 2-3 days for a total of 1-4 weeks. RESULTS AND CONCLUSION: Inverted microscope results showed that silk scaffold/3T3-L1 preadipocytes compounds presented with slender prominences that stretched out and migrated ahead to gradually connect together through a head-to-end fusion fashion and enter into meshes. Scanning electron microscope results demonstrated that in the silk scaffold/3T3-L1 preadipocytes compounds, cells tightly attached to silk scaffold, appropriately spread out, and secreted matrix. Silk shows better absorption for 3T3-L1 preadipocytes and maintains the normal morphology and functions of 3T3-L1 preadipocytes. Related Articles | Metrics

Select

Preparation and properties of carboxymethyl chitosan calcium Cai Wen-di, Chu Jin-xin, Han Bao-qin, Wang Chang-hong, Liu Wan-shun 2010, 14 (3):  567-570.  doi: 10.3969/j.issn.1673-8225.2010.03.046 Abstract ( 424 )   PDF (436KB) ( 560 )   Save BACKGROUND: Carboxymethyl chitosan is a water-soluble derivate modified from chitosan, with various biological activities. It is a good ligand of metal ion and can integrate Ca 2+ to prepare a novel biological material.  OBJECTIVE: To explore a method for preparing carboxymethyl chitosan calcium (CCC) and analyze its properties and structure. METHODS: CCC was produced by carboxymethyl chitosan reacting with solution of calcium chloride. The solubility, carboxymethylation degree, rotational viscosity, and calcium content of CCC were determined, and infrared and ultraviolet spectral analyses were performed. RESULTS AND CONCLUSION: The calcium content of CCC was approximately 15%. Compared with carboxymethyl chitosan, infrared spectrum and ultraviolet spectrum of CCC were changed. The prepared CCC is a new calcium compound through property and structural analysis. Related Articles | Metrics