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17 September 2011, Volume 15 Issue 38 Previous Issue    Next Issue

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Vascular endothelial growth factor transfected bone marrow mesenchymal stem cells cultured on bovine cancellous bone scaffold promote the formation of new vessels Chen Yi, Yin Xi-meng, Han Ya-xin, Wang Yan-feng, Liu Dan-ping, Tu Guan-jun 2011, 15 (38):  7031-7035.  doi: 10.3969/j.issn.1673-8225.2011.38.001 Abstract ( 362 )   PDF (1103KB) ( 311 )   Save BACKGROUND: After a small tissue engineering bone transplanted into animals, which can obtain enough nutrition by interstitial fluid penetration, but if a big one, it is insufficient by interstitial fluid penetration and must obtained by revascularization. OBJECTIVE: To observe the ability of bone marrow mesenchymal stem cells (BMSCs) transfected with vascular endothelial growth factor (VEGF) expression vector to promote vascularization on tissue engineering bone. METHODS: Bone defect model of the middle piece of both hand side ulnar bones of Japanese big ear rabbits was made. Transfected VEGF expression vector of autologous BMSCs to the protein of defatted bovine demineralized cancellous bone tissue engineering bone scaffold was implanted into left ulna defect as the experimental group. Autologous BMSCs combined with decalcifying, defatted and protein-free bovine cancellous bone scaffold of tissue engineering bone as the control group. At 12 weeks after operation, X ray photo observation, general specimen observation, hematoxylin-eosin staining and Masson staining histological section observation, MiFas picture analysis system quantitative analysis were performed. RESULTS AND CONCLUSION: The continuous calluses were formed in ulnar bone defect between experimental and control groups. Tissue section was stained with hematoxylin-eosin staining and Masson staining, and observed by MiFas picture analysis system quantitative analysis, which showed a large number of new bones between experimental and control groups, but new vessels in experimental group was significantly more than that in control group (P < 0.01); vessles were thick and closed to new bones. It is indicated that BMSCs of transfected VEGF expression vector combined with tissue engineering bone and implanted into animals can obviously promote the formation of new vessels. Related Articles | Metrics

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Repair of long segment bone defects with a novel bone tissue engineering scaffold beta-tricalcium phosphate/calcium polyphosphate fiber/poly-L-lactic acid composite and bone marrow mesenchymal stem cells Li Yi1, Liang Xiao-jun, Wang Kun-zheng, Chen Jun-chang, Yang Tuan-min, Tong Zhi-chao 2011, 15 (38):  7036-7040.  doi: 10.3969/j.issn.1673-8225.2011.38.002 Abstract ( 297 )   PDF (1481KB) ( 430 )   Save BACKGROUND: Bone tissue engineering scaffold beta-tricalcium phosphate/calcium polyphosphate fiber/poly-L-lactic acid (β-TCP/CPPF/PLLA) composite has good biocompatibility. OBJECTIVE: To explore the effect of β-TCP/CPPF/PLLA scaffold and bone marrow mesenchymal stem cells (BMSCs) in repairing rabbit long segment bone defects. METHODS: Forty New Zealand white rabbits were divided into BMSCs/β-TCP/CPPF/PLLA group (group A), pure β-TCP/CPPF/PLLA group (group B) and contrast group (group C) randomly. Animal models of long segment radius bone defect were established. The BMSCs/β-TCP/CPPF/PLLA were implanted into the right side of the radius defect (group A), while the pure β-TCP/CPPF/PLLA were implanted into the left side (group B) as control. We did nothing with the contrast group. The rabbits were sacrificed respectively after 4, 8, 12, 16 weeks and the X-ray film was performed at the same time to evaluate the repair effect in different groups. RESULTS AND CONCLUSION: X-ray film showed there was a small quantity of clouding bony callus in defect region after 2 weeks in group A. Marked osteogenesis screenage could be seen after 4 weeks. The defect region was filled with neonate osseous tissue completely and the bone medullary cavity was completely recanalized during 12-16 weeks. The defect region was filled partly in group B and group C, while group B was significant than group C (P < 0.01). X-ray score revealed that group A was much higher than group B at any time (P < 0.01). The BMSCs/β-TCP/CPPF/PLLA composite were capable of repairing long segment bone defects. Related Articles | Metrics

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Fabrication and characterization of a novel acellular bone matrix scaffold for bone tissue engineering Yang Qiang, Peng Jiang, Xia Qun, Ma Xin-long, Xu Bao-shan, Guo Quan-yi, Wang Ai-yuan, Zhao Bin, Zhang Li, Xu Wen-jing, Lu Shi-bi 2011, 15 (38):  7041-7044.  doi: 10.3969/j.issn.1673-8225.2011.38.003 Abstract ( 286 )   PDF (1171KB) ( 662 )   Save BACKGROUND: Natural bone acellular cells have many inadequacies. OBJECTIVE: To fabricate and characterize a novel acellular bone matrix scaffold for bone tissue engineering, and to detect its physical and chemical properties. METHODS: Bone column was prepared using canine bone cancellous bone from the femoral head, washed with high-pressure water gun, and decellularized using TritonX-100 and sodium deoxycholatethe. The scaffold was investigated by histological staining, scanning electronic microscope observation, Micro-CT and biomechanical analysis. RESULTS AND CONCLUSION: The new bone scaffold showed most of the extracellular matrix components after removal of the cell fragments after decellularization. Scanning electron microscopy and Micro-CT revealed a three-dimensional interconnected porous structure, with the pore diameter and porosity of nature bone. The longitudinal elastic modulus of the new scaffold was (552.56±58.92) MPa, and the intensity was (11.34±3.49) MPa. There was no significant difference between the natural bone and the new scaffold (P > 0.05). The new acellular bone matrix scaffold is a good alternative cell-carrier for bone tissue engineering. Related Articles | Metrics

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Preparation and properties of porous co-substituted calcium polyphosphate scaffold as bone repair material Jing Qi-fei, Zhang Xu, Xie Hui-xu, Wang Qi-guang, Zhang Xiao-hua, Yu Xi-xun, Wan Chang-xiu 2011, 15 (38):  7045-7048.  doi: 10.3969/j.issn.1673-8225.2011.38.004 Abstract ( 354 )   PDF (1483KB) ( 420 )   Save BACKGROUND: Ions doping is an important method for the modification of bioceramic. OBJECTIVE: To evaluate a novel co-substituted bioceramic scaffolds as bone repair material. METHODS: The microstructure and crystallization of the scaffolds were detected by scanning electron microscope and X-ray diffraction. Compression strength test, degradation test and cell culture experiment were assumed to evaluate the properties of KSCPP in vitro. After a short period of muscle pouches implantation, the performance of KSCPP in vivo was evaluated. RESULTS AND CONCLUSION: The results show that KSCPP scaffold has a higher compressive strength and degradation rate. Moreover, the MTT assay and implantation test reveal that the KSCPP scaffold exhibits lower cytotoxicity and better tissue biocompatibility than CPP and HA. The study proved the great potential of KSCPP in bone repair applications. Related Articles | Metrics

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Neointimal hyperplasia in the vessel grafts after seeding both endothelial cells and smooth muscle cells respectively transfected with tissue plasminogen activator and endothelial nitric oxide synthase Pei Fei, Chen Xu, He Rui, Li Jun-yan, Zhang Li 2011, 15 (38):  7049-7052.  doi: 10.3969/j.issn.1673-8225.2011.38.005 Abstract ( 300 )   PDF (1302KB) ( 475 )   Save BACKGROUND: Previous studies have shown that double layer cells implantation improves retention rate of vascular prosthesis endothelial cells. The fibrinolysis ability of endothelial cells (ECs) is improved after transfection with tissue plasminogen activator (tPA). OBJECTIVE: In order to enhance the antithrombotic ability and adhesion to polytetrafluoroethylene (PTFE) of ECs, tPA gene was introduced into ECs by pseudotyped retroviral vector. And endothelial nitric oxide synthase (eNOS) gene was introduced into smooth muscle cells (SMCs) to research whether eNOS gene transfection can inhibit the proliferation of neointimal hyperplasia with grafted both SMCs and ECs transfected with tPA. METHODS: The SMCs and ECs were implanted in PTFE grafts successively according to the following combination: ECs+SMCs, ECs/tPA+SMCs, ECs+SMCs/eNOS, ECs/tPA+SMCs/eNOS. Twenty-four adult New Zealand rabbits were randomly divided into 4 groups (n = 6). The above four types of PTFE covered with ECs and MSCs were transplanted respectively into the abdominal aorta of rabbits in four groups as bypass graft. RESULTS AND CONCLUSION: There was no difference in neointimal thickness between grafts seeded with ECs+SMCs and grafts seeded with ECs+SMCs/eNOS (P > 0.05). But compared with the grafts seeded with ECs/tPA+SMCs/eNOS, the neointimal thickness on grafts seeded with ECs/tPA+SMCs was significantly thicker (P < 0.05), while the neointimal thickness on grafts seeded with ECs+SMCs/eNOS was significantly thinner (P < 0.05). tPA gene in ECs can promote neointimal hyperplasia in the vessel graft seeded with ECs+SMCs, but eNOS gene in SMCs can inhibit this effect. Related Articles | Metrics

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Effect of fibrin glue associated with antisense to PCNA on preventing restenosis of vein grafts Wan Li, Wang Wen-jun, Cao Yuan-ping, Wang Qun, Liu Ji-chun 2011, 15 (38):  7053-7056.  doi: 10.3969/j.issn.1673-8225.2011.38.006 Abstract ( 325 )   PDF (1373KB) ( 374 )   Save BACKGROUND: Preliminary findings show that fibrin glue is not only a good non-restrictive, extravascular biodegradable stent, but also can prevent intimal and medial hyperplasia of vein grafts. It is also a good drug delivery system that can improve the extravascular membrane gene transfection efficiency. OBJECTIVE: To verify the effect of fibrin glue associated with antisense to PCNA on preventing restenosis of vein grafts. METHODS: Rabbit models of external jugular vein carotid artery bypass grafting were prepared and then randomized into model group, fibrin glue group and fibrin glue+antisense group. Commercially available fibrin glue and fibrin glue mixed with adenovirus expressing the antisense oligocleotides to PCNA were applied separately around vein grafts in the latter two groups, respectively. RESULTS AND CONCLUSION: Twenty-eight days after operation, the intimal and medial thickness and area was increased obviously in the model group and decreased significantly in the fibrin glue group (P < 0.01). A significant difference in the intimal and medial thickness and area was found between the fibrin glue group and fibrin glue+antisense group (P < 0.05). The mRNA and protein expressions of PCNA in the fibrin glue+antisense group was lower than those in the fibrin glue group (P < 0.05). The expression of PCNA in vein grafts can be inhibited by adventitial delivery of antisense to PCNA. The fibrin glue mixed with antisense has a synergistic effect on reducing the intimal and medial thickness and area of vein grafts. Related Articles | Metrics

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Biomatrix patch for abdominal defect repair in the mid-trimester fetal lambs Sun Jun-jie, Wang Feng-hua, Deng Gao-yan, Wang Pa, Mo Jia-cong 2011, 15 (38):  7057-7060.  doi: 10.3969/j.issn.1673-8225.2011.38.007 Abstract ( 294 )   PDF (1369KB) ( 341 )   Save BACKGROUND: Gastroschisis is a rare and serious congenital abdominal wall defect disease, and often leads to the development imbalance between the intestine and abdominal cavity with inflammatory thickened bowel. OBJECTIVE: To evaluate the feasibility of intrauterine abdominal defect repair of fetal lamb in the mid-trimester. METHODS: Eight healthy pregnant ewes (at 75-80 days of gestation, with single fetus) were divided into 2 groups. Group 1 (3 lambs): the abdominal wall defect was closed by strengthening suture; Group 2 (5 lambs): the abdominal wall defect was repaired by two layers of biomatrix. After the lambs delivered naturally, the abdominal walls were examined pathologically. RESULTS AND CONCLUSION: Three lambs of group 1 were successfully delivered, the abdominal incision healed well with a line-like scar, intra-abdominal adhesions was minor. A slight scar was seen on the tissue section. One lamb of the group 2 aborted, while 4 lambs delivered, the abdominal incision of the four lambs healed with obvious scar, intra-abdominal adhesions was minor. The fiber connective tissue was seen mainly on the tissue section. It was feasible to repair the abdominal wall defect of fetal lamb in mid-trimester. For fetal lamb, the abdominal wall scar was minor after direct suture. For larger abdominal wall defect, biomatrix patch was a promising material. Related Articles | Metrics

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Activation of T lymphocytes on local trauma after implantation of regenerated porus silk fibrion film Zhu Xiao-yan, Li Yong-lin, Xie Fang, Zhang Yan-jun, Huang Sai-nan, Li Ming-zhong, Qiu Yu-hua 2011, 15 (38):  7061-7065.  doi: 10.3969/j.issn.1673-8225.2011.38.008 Abstract ( 317 )   PDF (1261KB) ( 478 )   Save BACKGROUND: Silk fibroin is extracted from the natural polymer fibrin, which has a good physical and chemical properties and biocompatibility. While there is no report addressing activation of T lymphocytes after implantation of regenerated porous silk fibroin film at home and abroad.    OBJECTIVE: To investigate the activation of T lymphocytes in peripheral blood monouclear cells (PBMC), spleen and thymus on local trauma after implantation of regenerated porus silk fibrion film.   METHODS: Wound with an area of 2 cm×2 cm was established by removing SD rats’ skin of back, and randomly divided into two groups: experimental group and control group. Pretreated regenerated porous silk fibroin film was covered in experimental group, and the epidermis of the excisional skin covered silk fibroin film to undergo suture. At 3, 14, 28, 56, 90 days after operation, would healing and residue of silk fibroin film were observed. Two-color immunofluorescence and flow cytometry technology were used to analyze CD3+CD25+/ CD3+T cell percentage of PBMC, spleen and thymus in rats. RESULTS AND CONCLUSION: At the early stage of implantation, local and slight inflammatory cell infiltration could be seen between experimental and control groups, mainly lymphocytes. After 28 days, inflammatory cells were gradually decreased; the results between two groups were the same in the whole dynamic observation. Activated T cell of PBMC was transiently increased before 14 days, and then decreased. After 28 days, the level of activated T cell was tending towards stability. There was no significant difference between experimental and control groups (P > 0.05). T cells in spleen and thymus had small amounts of activation, and then began to decline and tended toward stability. Positive rate of CD3+CD25+/ CD3+T cell in thymus was slightly higher than that in spleen, and there was no significant difference between experimental and control groups (P > 0.05). It is indicated that regenerated porus silk fibrion film plays a small part in activation of T lymphocyte, and causes a weaker ability of cellular immune response. Related Articles | Metrics

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Intravascular biocompatibility of poly (3-hydroxybutyrate- co-3-hydroxyhexanoate) Wu Song, Liu Ying-long, Tang Yue, Wang Qiang, Wan Feng, Qu Xiang-hua, Chen Guo-qiang 2011, 15 (38):  7066-7070.  doi: 10.3969/j.issn.1673-8225.2011.38.009 Abstract ( 265 )   PDF (588KB) ( 416 )   Save BACKGROUND: The degradable poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) has superior mechanical property and biocompatibility. OBJECTIVE: To elucidate the intravascular biocompatibility of PHBHHx in vivo. METHODS: We developed hybrid materials based on decellularized xenogenic vascular scaffolds that were coated with PHBHHx and implanted it into the abdominal aorta of New Zealand rabbits. The decellularized xenogenic pulmonary artery patch without PHBHHx coating served as the control. The implanted patches were determined for the histology, immunofluorescence staining, scanning electron microscopy and calcium contents at 1, 4 and 12 weeks after the surgery. RESULTS AND CONCLUSION: Hybrid patches exhibited smooth lumen surface without thrombus, the intimal hyperplasia was mild and recellularization was complete; immunofluorescence staining showed that the endothelial cells in the neointima were positive for CD31, with continuous single-layer arrangement, interstitial cells were positive for smooth muscle actin; the calcium content in hybrid patches was obviously lower than that in uncoated patches. PHBHHx shows a remarkable intravascular biocompatibility in vivo and is believed as an ideal candidate for lumen coating of cardiovascular tissue engineering. Related Articles | Metrics

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Biocompatibility of self-made calf deproteinized cancellous bone with rabbit cortical bone-derived osteoblasts Meng Jia-rong, Chen Chang-qing, Zhang Shan-tao, Lian Ke-jian, Huang Li-xian, Ding Zhen-qi, Yin Xiao-feng 2011, 15 (38):  7071-7074.  doi: 10.3969/j.issn.1673-8225.2011.38.010 Abstract ( 339 )   PDF (1393KB) ( 376 )   Save BACKGROUND: Heterogeneous deproteinized bone has the same structure with the host bone, and the antigen is low causing little or no host immune response. OBJECTIVE: To observe the biocompatibility of self-made calf eproteinized cancellous bone with rabbit cortical bone-derived osteoblasts. METHODS: Cells were isolated and cultured with enzyme digestion methods in vitro from the ulnar cortical bone of 3-month-old New Zealand white rabbits. Cells of the 3rd generation were attained for the following experiments. Rabbit cortical bone-derived osteoblasts were co-cultured with self-made calf eproteinized cancellous bone in vitro. Pure osteoblasts were used as controls. The cell growth, scaffold degradation and adherence condition were detected. RESULTS AND CONCLUSION: The calf eproteinized cancellous bone was porous, and its pores were connected between each other. And with the culture time extended, cells grew and proliferated rapidly. On the 3rd day of co-culture, there were some cells adhered and spread on the scaffold; on the 6th day, cells were fully extended, showing long spindle; on the 10th day, cells secreted lots of extracellular matrix, presented with overlapping growth and were connected into the network. On the 9th and 12th day, the cell proliferation and secretion in the coculture group were superior to the control group (P < 0.05); Alkaline phosphatase activity and osteocalcin level were also higher in the coculture group than the control group (P < 0.05). The self-made calf deproteinized cancellous bone had good biological compatibility with rabbit cortical bone-derived osteoblasts. Related Articles | Metrics

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Screen and synthesis of functionalized self-assembling peptide nanofiber scaffolds for promoting vascular endothelial cells growth Wang Xiu-mei, Qiao Lin 2011, 15 (38):  7075-7079.  doi: 10.3969/j.issn.1673-8225.2011.38.011 Abstract ( 435 )   PDF (1732KB) ( 411 )   Save BACKGROUND: Due to the unique biocompatibility and bioactivity, functionalized self-assembling peptide nanofiber scaffolds can be used to promote angiogenesis. OBJECTIVE: To design and screen the functionalized self-assembling peptide nanofiber scaffolds that can promote endothelial cell angiogenesis. METHODS: The designed and selected functionalized peptide sequences were directly extended on the self-assembling peptide RADA16-I through solid phase synthesis at the C-termini to increase the angiogenic activities of RADA16-I peptide scaffolds by CPC Scientific. The functionalized self-assembling peptide was mixed with RADA16-I at the ratio of 1: 1. Then, the mixture was added into sterile culture plate and cultured at 37 ℃ overnight to form gel. pH value was mediated by changing culture medium. Human umbilical vascular endothelial cells were cultured on the surface of the peptide scaffolds for two-dimensional culture. The functionalized self-assembling peptide nanofiber scaffolds were characterized by circular dichroism spectrum and atomic force microscopy image. RESULTS AND CONCLUSION: The structure of functionalized self-assembling peptide nanofiber scaffolds is quite similar with Matrigel and they are uniformed nanofiber materials. These two designer functionalized peptides, KLT and PRG, have been demonstrated to significantly enhance endothelial cell adhesion, survival and rapid proliferation. The scaffolds of RAD/KLT and RAD/PRG can be used for the study of promoting endothelial cell angiogenesis. Related Articles | Metrics

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Biocompatibility of three-dimensional scaffolds with adipose-derived stem cells Guo Xiang, Zhao Heng 2011, 15 (38):  7080-7084.  doi: 10.3969/j.issn.1673-8225.2011.38.012 Abstract ( 361 )   PDF (1657KB) ( 364 )   Save BACKGROUND: An optimal three-dimensional scaffold is essential for construction of tissue engineered trachea. OBJECTIVE: To observe the biocompatibility of adipose-derived stem cells (ADSCs) with poly(lactic acid-glycolic acid) and poly(lactic acid-glycolic acid-trimethylene carbonate) scaffolds.  METHODS: ADSCs were isolated and cultured by explant culture method. Cell surface markers were evaluated by flow cytometry and the multilineage differentiation ability was investigated. The biocompatibility of ADSCs with poly(lactic acid-glycolic acid) and poly(lactic acid-glycolic acid-trimethylene carbonate) scaffolds was observed by scanning electron microscopy. RESULT AND CONCLUSION: ADSCs were seeded into the two kinds of scaffolds and cultured in vitro. Scanning electron microscopy showed that ADSCs were spherical and well attached to the scaffolds with lamellipodia and conglobate connection. The poly(lactic acid-glycolic acid) and poly(lactic acid-glycolic acid-trimethylene carbonate) scaffolds with porous structure were highly biocompatible and noncytotoxic as determined by ADSCs adhesion and proliferation. Related Articles | Metrics

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Preparation and in vitro release characteristics of chitosan microspheres loading Helicobacter pylori whole cell protein antigen Liu Wei, Xie Yong, Liu Zhi-jun 2011, 15 (38):  7085-7089.  doi: 10.3969/j.issn.1673-8225.2011.38.013 Abstract ( 334 )   PDF (1456KB) ( 365 )   Save BACKGROUND: Chitosan microspheres loading Helicobacter pylori whole cell protein antigen prepared by different methods have different the package rates and controlled-release effects. OBJECTIVE: To prepare chitosan microspheres loading Helicobacter pylori whole cell protein antigen and observe the release characteristics in vitro. METHODS: Berthold precipitation method was used to prepare chitosan microspheres and the preparation was optimized; scanning electron microscope and particle size analyzer were used to observe the shape and size measurement of chitosan microspheres; the BCA Protein Assay Kit was used to measure the loading efficiency, loading capacity and releasing rate of microspheres. RESULTS AND CONCLUSION: We chose the best preparation program of chitosan microspheres from 32 species preparation programs: the best preparation program was the material of sea shell chitosan, 1% concentration of acetic acid, sodium sulfate for precipitating agent and 5.0 pH value, non-use of ultrasonic treatment. SEM results showed that the microspheres presented with smooth round and dense, diameters ranged from 1.0 μm to 5.0 μm; Antigen loading efficiency was 79.92%, loading capacity was 16.47%; Release experiment in vitro showed that the total antigen releasing rate was 20.39%, showing a slow-release status. Related Articles | Metrics

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Chitosan-collagen scaffold and chondrocytes growth Zhan Xing-wang, Wei Shu-dong, Jiang Yan, Wang Wen-liang, Zhan Xing-xiu 2011, 15 (38):  7090-7094.  doi: 10.3969/j.issn.1673-8225.2011.38.014 Abstract ( 263 )   PDF (1589KB) ( 722 )   Save BACKGROUND: At present, the materials of cartilage framework are various, but not one kind of material can fully comply with requirements of cartilage repair. OBJECTIVE: To observe the growth of cartilage cells in mixed chitosan-collagen scaffold. METHODS: The porous chitosan-collagen scaffold was fabricated by the freeze-drying technique using 2% collagen and 3% chitosan. The chondrocytes at passage 2 were planted in chitosan-collagen scaffolds (experimental group) or cell panels (control group). The porosity, water absorption and internal structure of the scaffold were observed. The cell attachment capacity and proliferation of chondrocytes was valuated by MTT and hematoxylin-eosin staining. Expressions of type Ⅱ collagen and proteoglycan mRNA were valuated by RT-PCR. RESULTS AND CONCLUSION: The water absorption of chitosan-collagen scaffold was (80.0±0.55)%, porosity was (88.5±1.5)%, and the pore size was 100-150 μm. The scaffold facilitated the penetration and attachment of chondrocytes. After two weeks, RT-PCR showed that collagen and proteoglycan mRNA were expressed in the experimental group, but only a little in the control group. These results showed that the chitosan-collagen scaffold (2% collagen and 3% chitosan) can provide an appropriate environment for the generation of chondrocytes and have a potential application in the cartilage tissue engineering scaffold field. It is one kind of good carrier for restoration and reconstruction of cartilage. Related Articles | Metrics

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Chitosan hydrogel microsphere-templated microcapsules carrying heparin via layer-by-layer self-assembly Wu Ying-feng, Guo Hai-li, Li Juan 2011, 15 (38):  7095-7099.  doi: 10.3969/j.issn.1673-8225.2011.38.015 Abstract ( 397 )   PDF (429KB) ( 472 )   Save BACKGROUND: Electrostatic layer-by-layer (LbL) self-assembly is a simple, effective and novel approach to carrying macromolecules into microcapsule carriers. OBJECTIVE: To prepare chitosan (CS) microcapsules to control the releasing of heparin (Hep) by LbL. METHODS: CS microspheres were fabricated by a sodium sulfate-based precipitation process and then used as positively charged templates for polyelectrolyte multilayer coatings to carry heparin by the LbL self-assembly technique. The polycation was CS and the polyanion was Hep. The microcapsule was formed via coating {CS/Hep}3 on CS hydrogel template. The microcapsules composed of {CS/ Hep}3 on CS hydrogel templates were confirmed by fluorescence inverted microscopy, confocal laser scanning microscopy and laser particle size analysis. The assembly of polyelectrolyte layers on CS hydrogel microspheres was monitored by Zeta Potential Analyzer. RESULTS AND CONCLUSION: The resulting microcapsules were about 1 μm in average diameter, and allowed spontaneous loading of heparin through electrostatic interaction, with the encapsulation efficiency and carrying capacity of 83.8% and 3.05%, respectively. Related Articles | Metrics

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Modified poly (L-lactic acid)-poly (L-lysine) polymer induces bone marrow stromal cells initial adhesion Mao Xue-li, Ling Jun-qi, Xiao Yin, Peng Hui 2011, 15 (38):  7100-7104.  doi: 10.3969/j.issn.1673-8225.2011.38.016 Abstract ( 404 )   PDF (1444KB) ( 504 )   Save BACKGROUND: It is an effective strategy that integrating the activated ligands into the surface of biomaterial scaffolds to enhance and regulate the material affinity for cells and cell compatibility. OBJECTIVE: To develop poly (L-lactic acid)-poly (L-lysine) (PLLA-PLL) to enhance cell initial adhesion on the polymer surface. METHODS: Different composition polymer films (PLLA139-PLL131, PLLA77-PLL72, PLLA45-PLL246) were synthesized through ring-opening metathesis polymerization. BMSCs were seeded onto these different composition polymer surfaces ( PLLA and TCP served as the control), and detected the best composition of PLLA-PLL polymer film for cell adhesion and proliferation. RESULTS AND CONCLUSION: PLLA-PLL films increased the number of initially attached BMSCs in both serum and serum free conditions compared with PLLA. Increased PLL content in the PLLA-PLL co-polymer led to increase cell attachment, significant difference changes were detected on copolymer PLLA77-PLL72 (P< 0.05). Continued culture confirmed that PLLA77-PLL72 enhanced cell proliferation. BMSCs cultured on the PLLA-PLL had a clear and well organized F-actin fibre expression. Related Articles | Metrics

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Immunodetection to Escherichia coli of polydiacetylene nanoparticles Guo Xun-zhi, He Jian-tai, Zhang Yang-de, Zhou Wei-hua 2011, 15 (38):  7105-7108.  doi: 10.3969/j.issn.1673-8225.2011.38.017 Abstract ( 245 )   PDF (1402KB) ( 380 )   Save BACKGROUND: PCR, ELISA, immunofluorescence-ball method, and gene chip technology for rapid detection of enteric pathogens take hours to get results and are not suitable for on-site rapid test. OBJECTIVE: To prepare polydiacetylene (PDA) nanoparticles for immunodetection to Escherichia coli. METHODS: PDA nanoparticles were prepared with sonication. RESULTS AND CONCLUSION: The prepared PDA nanoparticles had uniform particle size, narrow distribution, and stable structure. Escherichia coli dilution was dropped into PDA nanoparticle dilution for 2 minutes, and the solution color turned from blue to red, indicating that PDA nanoparticles were rapid in detection speed. The graphs of ultraviolet-visible absorption spectroscopy, transmission electron microscope, and nanosizer displayed big changes with Escherichia coli and antibody PDA nanoparticle. The experimental results signed that the rat polyclonal antibody is a functional molecule of the immunodetection to Escherichia coli of PDA nanoparticles, and the reaction of antigen-antibody is specific. Related Articles | Metrics

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Characterization of nano-hydroxyapatite/single walled carbon nanotube composite Pu Hui, Li Jun, Li Xiao-li, Zhang Yang-de, Gong Lian-sheng 2011, 15 (38):  7109-7112.  doi: 10.3969/j.issn.1673-8225.2011.38.018 Abstract ( 409 )   PDF (1192KB) ( 371 )   Save BACKGROUND: Hydroxyapatite has robustness close to natural bone and good biocompatibility, but its mechanical properties are poor. OBJECTIVE: To study the properties of a new bioactive material (nano-hydroxyapatite/single walled carbon nanotube composite, HA/SWNT). METHODS: HA/SWNT nanoparticles were prepared by using in situ synthesis method. Infrared spectrogram (IR), microstructure, X-ray diffraction (XRD), and mechanical properties were detected. The bending strength and fracture toughness of SWNT/HAp composites with different SWNT contents were compared. RESULTS AND CONCLUSION: Bending strength of HA/SWNT nanoparticles increased by 50% maximum, and reached 73 MPa. Its fracture toughness was improved by almost 300% and reached 2.6 MPa•m1/2. With the increase of SWNT contents, the bending strength and fracture toughness of the composites were gradually increased. Various performance of HA/SWNT composites are improve greatly to overcome the shortcomings of traditional bone materials. Related Articles | Metrics

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Preparation and characterization of nano-hydroxyapatite/carboxymethychitosan-sodium alginate bone cement composite material Xiao Hai-jun, Xue Feng, He Zhi-min, Jin Fen-qin, Shen Yu-chun 2011, 15 (38):  7113-7117.  doi: 10.3969/j.issn.1673-8225.2011.38.019 Abstract ( 397 )   PDF (1691KB) ( 621 )   Save BACKGROUND: Bone adhesives have more or few shortcomings themselves at present. OBJECTIVE: To develop a new kind of bioactive bone cement that can be used as fracture adhesion. METHODS: Nano-hydroxyapatite/carboxymethychitosan-sodium alginate bone cement composite material as solid phase was prepared through a co-precipitation method, and citric acid derivant as liquid phase was prepared for solution. By optimized experimentation in situ setting, the appropriate prescription of the cement was screened out according to the test of setting time, compressive strength, tensile strength, anti-washout ability, and microstructure and crystal construction of the cement were characterized by using Fourier transform infrared spectroscopy and scanning electron microscope. RESULTS AND CONCLUSION: When the mass ratio of nano-hydroxyapatite/carboxymethychitosan-sodium alginate was 65/35 (among carboxymethychitosan/sodium alginate 4:1) and liquid/solid was 1.0: 0.5 (g: mL), the prepared cement was paste-like with good plasticity and anti-washout ability; the setting time was 12 to 18 minutes; the compressive strength was (4.5±2.1) MPa; the tensile strength of the femoral head of pigs had no difference at 25 ℃ and 37 ℃ in vitro (P > 0.05); the tensile strength at    2 hours was 94% similar as that at 24 hours after the setting; the range of the porous structure was 100-300 µm; Nano-hydroxyapatite was well-distributed in the porous structure. The nano-hydroxyapatite/carboxymethychitosan-sodium alginate bone cement has good biological activity, appropriate compressive strength, and preferable adhesive strength. Related Articles | Metrics

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Vascular endothelial growth factor and nano-hydroxyapatite/collagen composite in the repair of femoral defect in rats Xu Cheng-zhen, Yang Wen-gui, He Xiao-feng, Zhou Li-tao, Han Xue-kun, Xu Xiao-feng 2011, 15 (38):  7118-7122.  doi: 10.3969/j.issn.1673-8225.2011.38.020 Abstract ( 407 )   PDF (472KB) ( 482 )   Save BACKGROUND: Previous studies have confirmed that nano-hydroxyapatite/collagen (nHAC) and mesenchymal stem cells for repair of bone defect have the ability of bone formation in vivo. OBJECTIVE: To observe the effects of vascular endothelial growth factor (VEGF) and bone marrow mesenchymal stem cells (BMSCs), nHAC composite in the repair of femoral defect in rats. METHODS: Sprague-Dawley rat models of middle part of the femur defect were established and randomly assigned to two groups. Control group was implanted with BMSCs/nHAC composite. Experimental group was implanted with VEGF/BMSCs/nHAC composite. At 2, 4 and 8 weeks postoperation, imaging and histology observation of femoral samples were performed. At 8 weeks postoperation, scanning electron microscopy was performed in new bony callus environment. RESULTS AND CONCLUSION: nHAC composite implantation in the rats did not show rejection or inflammatory reaction. Moreover, bone formed rapidly using VEGF and BMSCs, nHAC composite, which exhibited better bone regeneration capacity compared with BMSCs/nHAC composite. The way of ossification mainly was endochondral ossification. It is presumed that VEGF promoted the formation of local microvessels, differentiation and proliferation of osteoblasts, speeded up the speed of endochondral ossification, shortened bone repair time, and elevated the quality and velocity of osteanagenesis. Related Articles | Metrics

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Therapeutic effect of microencapsulation carrier preparation for in situ stereotype on skin ulcers of diabetic rats Wang Xiao-mei, Wang Fu, Yang Xiao-hui, Jin Cheng-ji, Li Xiang 2011, 15 (38):  7123-7126.  doi: 10.3969/j.issn.1673-8225.2011.38.021 Abstract ( 377 )   PDF (1324KB) ( 314 )   Save BACKGROUND: Insulin as one of the components of microencapsulation carrier preparation for in situ stereotype can promote the ulcer healing. OBJECTIVE: To evaluate the therapeutic effect of microencapsulation carrier preparation for in situ stereotype on skin ulcers of diabetic rats. METHODS: Sprague-Dawley (SD) rats were used to establish diabetic rat models by intraperitoneal injection of streptozotocin (STZ) and to set up skin ulcer models by surgical methods. All rats were randomly divided into 4 groups by different interventions:  microencapsulation preparation with effective component group (MPE), microencasultion preparation without effective component group (MPNE), general preparation with effective component group (GE), blank control group (BC). Ulcer area was measured at regular time intervals. In the first 14 days, full-thickness skin wounds were brought to make histological observation and determine the positive cell numbers expressing epidermal growth factor receptor (EGFR) and fibronectin (FN) . RESULTS AND CONCLUSION: The skin ulcer healing time of MPE group was the shortest compared with the other three groups (P < 0.05 or P < 0.01). The number of EGFR and FN positive cells in MPE group was more than that of any other three groups (P < 0.05 or P < 0.01). Microencapsulation carrier preparation for in situ stereotype can promote the healing course of skin ulcer in diabetic rats. Related Articles | Metrics

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Mechanical properties of hyaluronic acid modifying chitosan/collagen/nano-hydroxyapatite composite scaffold and its effect on osteoblast proliferation Liu Lu, Li Rui-xin, Zhang Li, Guo Yong, Chen Xue-zhong, Wang Liang, Dong Li-zhi, Zhang Xi-zheng 2011, 15 (38):  7127-7131.  doi: 10.3969/j.issn.1673-8225.2011.38.022 Abstract ( 399 )   PDF (526KB) ( 488 )   Save BACKGROUND: Seed cell exerting its function is required to depend on the extracellular matrix in tissue engineering, so that biocompatible material is important to be selected. OBJECTIVE: To prepare a novel composite scaffolds of chitosan/collagen/nano-hydroxyapatite (HA-CS/Col/nHAP) and to optimize the technology of tissue engineered-stents according to the circumstances of cell adhesion. METHODS: Chitosan was modified by hyaluronate acid. The structure was observed by differential scanning calorimetry and the Fourier transformed infrared spectroscopy. Three composites of HA-CS/Col/nHAP according to different ratio of chitosan and collagen solution (1: 2; 1: 1 and 2: 1) were prepared. The composite scaffolds were co-cultured with osteoblast MC3T3-E1, and the proliferation and cell growth curve were measured by CCK-8 method. RESULTS AND CONCLUSION: Hyaluronic acid and chitosan were crosslinked with amide linkage. Pore size was on the range from 50 μm to 250 μm. Porosity was increased with increased collagen level and elastic modulus, but density was reduced. Increased collagen content was beneficial for cell adhesion and proliferation on stent in the primary phase of cell co-culture. However, from day 10, no significant difference was determined among three samples. At the beginning of cell culture, cells adhered to the airspace insides the composite scaffolds. In the following days, cells grew in a colony manner, and cell-cell junction could be easily observed. These indicate that HA-CS/Col /nHAP composite scaffolds can improve the adhesion and proliferation of osteoblast. The ratio of chitosan to collagen volume at 1: 1 was optimal. Related Articles | Metrics

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Esophageal repairing acellular biological tissues fixed by EX-810 Li Li, Gu Zhi-peng, Chen Jian, Yu Xi-xun 2011, 15 (38):  7132-7134.  doi: 10.3969/j.issn.1673-8225.2011.38.023 Abstract ( 341 )   PDF (867KB) ( 303 )   Save BACKGROUND: Natural biological tissue materials can be gradually absorbed, and can induce tissue-specific remodeling, which are ideal esophageal repair materials. OBJECTIVE: To investigate the characteristics of porcine esophageal tissues fixed with ethylene glycol diglycidyl ether (EX-810). METHODS: The porcine esophageal tissues were treated with 4% EX-810 for 1 hour to 120 hours, and then they were examined morphologically with the electron microscope. The fixation index determination and the biomechanics test were also performed to study the degree of cross-linking and the effect of cross-linking on the mechanical properties. RESULTS AND CONCLUSION: The antigenicity of esophageal tissues could be diminished by EX-810 through getting rid of cells in the esophageal tissues or reducing the level of free amino groups in the esophageal tissues. The structural integrity of collagen in esophageal tissues could be preserved after treating with EX-810. In this study, it was also found that the EX-810-fixed porcine esophageal tissues showed better mechanical properties than the native esophageal tissues, and had a changed stress-strain characteristics. It could meet the standard used as the prosthetic materials for bridging esophageal defects. The EX-810-fixed porcine esophageal tissues showed low antigenicity and proper mechanical properties, and the structural integrity of collagen in them could also be preserved. Related Articles | Metrics

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Mechanical study of laser welded new Co-Cr alloy Liang Rui-ying, Zhao Yan-ping, Wen Li-ming, Bai Yu-hong, Wu Wen-hui, Xu Yan-li, Meng He 2011, 15 (38):  7135-7138.  doi: 10.3969/j.issn.1673-8225.2011.38.024 Abstract ( 393 )   PDF (1082KB) ( 335 )   Save BACKGROUND: There are no reports on laser welding about a kind of Co-Cr alloys, which do not include Ni and Be nowadays. OBJECTIVE: To apply laser welding technique to prepare a new Co-Cr alloy in order to provide welding parameters for clinic application. METHODS: Sixty plastic plate patterns (0.5 mm×6 mm×30 mm) were casted from new Co-Cr alloy. All the plates were randomly divided into 6 groups, one as control group, and the others as examination group. The plates of examination group were perpendicularly cut at the center of the plates. After the cut halves were fixed in a jig, they were laser welded using a NG:YAG laser at a several level output energy in increments of 30 V from 220 to 340 V. The spot diameter and pulse duration employed was 0.6 mm and 10 ms. Uncut specimens served as the non-welded control specimens. Tensile testing was conducted and the breaking force was recorded and the data was statistically analyzed.  RESULTS AND CONCLUSION: The tensile strength of laser welding New Co-Cr alloys increased with the electric voltage. The elongation increased with the electric voltage at the electric voltage lower than 280 V, but showed contrary trend when the electric voltage higher than 280 V. The tensile strength and elongation was (679.94±46.87) MPa and (5.91±0.38)% respectively at the optimized welding parameters. The tensile strength and elongation of laser welded New Co-Cr alloy under the optimized parameters (280 V, 10 ms, spot diameter 0.6 mm) can be satisfied with the clinical requirement. Related Articles | Metrics

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Influence of N+ ion sputtering on bacteria adhesion of Ni-Cr alloy Shi Yan-lei 2011, 15 (38):  7139-7141.  doi: 10.3969/j.issn.1673-8225.2011.38.025 Abstract ( 381 )   PDF (878KB) ( 320 )   Save BACKGROUND: Ni-Cr alloy is widely used in dental field. A large number of experiments have been performed to study its mechanical properties, corrosion resistance and biocompatibility. OBJECTIVE: To study the influence of N+ ion sputtering on bacteria adhesion of clinically used Ni-Cr alloy. METHODS: A hundred and forty-four pieces of Ni-Cr alloy were made, and 72 were randomly chosen. Then N+ ion sputter was used to the surface modification of chosen Ni-Cr alloys as experimental group, while others served as controls. Strep. sanguis, Actinomyces viscosus, Candida albicans were adhered onto the surfaces of Ni-Cr alloys, and then the number of bacteria was assayed by means of clone forming unit (CFU) method. RESULTS AND CONCLUSION: At 24, 48 and 168 hours, the number of the adhered Strep. sanguis, Actinomyces viscosus, Candida albicans was significantly reduced in N+ ion sputtering Ni-Cr alloy group (P < 0.001), indicating that N+ ion sputtering may reduce bacterium adhesion on Ni-Cr alloy. Related Articles | Metrics

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The dimensional accuracy of different polyvinyl siloxanes impression techniques Zeng Zhi-hong, Xu Song 2011, 15 (38):  7142-7144.  doi: 10.3969/j.issn.1673-8225.2011.38.026 Abstract ( 354 )   PDF (1121KB) ( 502 )   Save BACKGROUND: The dimensional accuracy of impression is closely related with the suitability of final prosthesis. OBJECTIVE: To evaluate the linear dimensional accuracy of dental casts made with one-step or two-step polyvinyl siloxanes impression techniques. METHODS: One-step or two-step polyvinyl siloxanes impression techniques were used respectively to make 10 dental impressions of standard dental cast in an environment with temperature and humidity similar to clinical oral cavity. Cast was made on each impression using ultrahard plaster. The length, width, height of each cast was measured by vernier caliper. RESULTS AND CONCLUSION: The cast measurements obtained by two-step polyvinyl siloxanes impression techniques were closer to the standard cast measurements than one-step impression techniques. But the measurements difference between different impression techniques and standard cast had no statistical significance. Related Articles | Metrics

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Bond strength of GGW titanium bonding porcelain to cast titanium Wang Xiao-jie 2011, 15 (38):  7145-7148.  doi: 10.3969/j.issn.1673-8225.2011.38.027 Abstract ( 334 )   PDF (1135KB) ( 444 )   Save BACKGROUND: High production costs and weak bonding strength of titanium limit the use of titanium porcelain, in order to reduce the cost of titanium porcelain, replace nickel-chromium alloy porcelain repair, and improve security of fixed dental prosthetics. A kind of new titanium-bonding-porcelain powder GGW is produced and the properties are tested. OBJECTIVE: To test the bond strength of new titanium-bonding-porcelain GGW to cast titanium. METHODS: A three-point bending test was used according to ISO 9693 and SEM with energy-dispersive spectrometry analysis to evaluate the bond strength of GGW titanium bonding porcelain to cast titanium. RESULTS AND CONCLUSION: The bond strength of new titanium-bonding-porcelain GGW to cast titanium was higher obviously than that of Super Porcelain TI-22 to cast titanium. GGW titanium experimental bonding porcelain with titanium had chemical reaction, formed by a large number of parallel arrays of layered substructure composed of fracture energy higher crystalling phase organization. Titanium/porcelain rupture occurred in these crystal structure layers, the fracture mode performance for the intergranular and wear crystal mixed form. Titanium-bonding-porcelain GGW has a promising future. Related Articles | Metrics

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Cytotoxicity of nano-silver-zirconium phosphate antibacterial polyurethane Zou Zhao-wei, Shi Fu-jun, Huang Zong-hai, Chen Fei, Li Qiang, Cui Chun-hui 2011, 15 (38):  7149-7152.  doi: 10.3969/j.issn.1673-8225.2011.38.028 Abstract ( 317 )   PDF (1297KB) ( 807 )   Save BACKGROUND: Polyurethane as a popular medical polymer material plays a crucial role in many artificial organs and medical devices. OBJECTIVE: To prepare nano-silver-zirconium phosphate antibacterial polyurethane and to observe its cytotoxic effect on L929 cells. METHODS: L929 cells were incubated into 96-well plates and divided into three groups: experimental group treated with antibacterial polyurethane, positive control group with phenol solution, negative control group with high-density polyethylene extract. The cell morphology was observed under inverted phase contrast microscope after 24, 48 and 72 hours. The relative growth rate (RGR) was calculated and the cytotoxicity was graded by with MTT method. RESULTS AND CONCLUSION: After cultured for 24, 48 and 72 hours, the RGR of L929 cells in the experimental group was 94.3%-97.9%, 94.5%-99.8% and 90.8%-96.3%, respectively. The cytotoxicity of the antibacterial polyurethanes was graded level Ⅰ. Antibacterial polyurethane has no cytotoxicity to L929 cells and shows good biocompatibility, meeting the safety standards of biomedical materials. Related Articles | Metrics

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HEAL-ALL tissue patch in prevention of Frey syndrome after parotidectomy Huang Dai-ying, Li Xiang, Nie Er-min, Guo Bing 2011, 15 (38):  7153-7156.  doi: 10.3969/j.issn.1673-8225.2011.38.029 Abstract ( 367 )   PDF (1317KB) ( 463 )   Save BACKGROUND: Recently, great achievements of acellular dermal matrix which is used to prevent Frey syndrome have been reported. OBJECTIVE: To evaluate the role of oral tissue patch (HEAL-ALL) in preventing Frey syndrome after parotidectomy. METHODS: Eighty-four patients were divided into two groups. Thirty-five patients of groupⅠwho received a superficial lobe parotidectomy and oral tissue patches were put between the fascia parotidea masseterica flap and the remaining parotid tissue. Group 2 consisted of 49 patients who underwent the parotidectomy. All patients were evaluated for gustatory sweating by identical phone. Sixty randomly chosen patients (group Ⅰ30, group Ⅱ30) were evaluated using the Minor Starch Iodine Test (MSIT). RESULTS AND CONCLUSION: The responses to phone showed presence of Frey syndrome in 1 of 30 in groupⅠ, whereas group Ⅱ showed 27 of 49 patients presented with Frey syndrome. The objective results test by those who underwent the MSIT revealed a 6.67% (2) and 73.33% (22) incidence of Frey syndrome in groupsⅠ and Ⅱ, respectively. There was significant difference between the two groups (P < 0.01). HEAL-ALL tissue patch is shown to be an effective way for preventing Frey syndrome post-parotidectomy. Related Articles | Metrics

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Effects of Au-Pt based porcelain-fused-metal crown on gingival health of the restored teeth Zhang Xue-jing, Wei Ji-ying, Chen Fang, Zhang Jun, Yang Lan 2011, 15 (38):  7157-7160.  doi: 10.3969/j.issn.1673-8225.2011.38.030 Abstract ( 299 )   PDF (1528KB) ( 373 )   Save BACKGROUND: There are many types of porcelain-fused-metal (PFM) repair materials, each material has its own properties and toxic effects on periodontal tissue cells. OBJECTIVE: To explore the effect of Au-Pt based PFM crown on the periodontal tissue of restored teeth. METHODS: Twenty-six maxillary incisors that possessed Au-Pt based PFM crowns in 21 patients were involved in the study. The contralateral homonymy nature teeth were treated as control teeth. The patients were followed up 6 to 8 months after the placement of the crowns. RESULTS AND CONCLUSION: All of the restorations were clinically accepted, either in marginal depth or in marginal discrepancies. There were no significant differences of plaque index and the concentration of vascular endothelial growth factor and tumor necrosis factor-α between the test and the control teeth after the placement of Au-Pt based PFM crown (P > 0.05). However, the probing depth, sulcus bleeding index and gingival cervicular fluid volume of the test teeth were significantly higher than those of the control teeth (P < 0.05). Au-Pt based PFM crown has negative influences on gingival health of the restored teeth. Related Articles | Metrics

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Multi-fiber posts restore molar residual root and crown Liu Xin-qing, Liu Yi-zhen, Liu Shu-qin 2011, 15 (38):  7161-7164.  doi: 10.3969/j.issn.1673-8225.2011.38.031 Abstract ( 306 )   PDF (1486KB) ( 559 )   Save BACKGROUND: Cast metal posts with big elastic modulus and poor biocompatibility can result in apical root fractures that are difficult to remove during residual molar crown repairment.  OBJECTIVE: To evaluate the therapeutic effects of multi-fiber posts on the restoration of the molar residual root and crown. METHODS: A total of 26 patients with 31 molars were included. After satisfactory root canal therapy, the teeth were repaired using two or three glass fiber posts and zirconia-ceramic crowns. RESULTS AND CONCLUSION: During 12-24 months of clinical follow-up, one had food impaction for bad adjacency, one had abscission of all-ceramic crown, one had porcelain collapse caused by hard food biting. No loosening, fracture and gap existed among fiber post, composite resin core, dentine and crown. No dislodgment or fracture of posts or roots was observed in restorations. Multi-fiber post and cores and all-ceramic crown are reliable and ideal materials in the restorations of molar residual root and crown. Related Articles | Metrics

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Application of glass ionomer and light-cured resin sealant to the pit and fissure of deciduous teeth Ren Fei, Liu Jian-ping, Huang Shao-hong, Li Yan-rong, Fan Wei-hua, Chen Xiao-chun, Chen Qing 2011, 15 (38):  7165-7169.  doi: 10.3969/j.issn.1673-8225.2011.38.032 Abstract ( 409 )   PDF (432KB) ( 591 )   Save BACKGROUND: Traditional glass ion sealant has a poor abradability and a low rupture strength. The sealant on the occlusal surfaces easily fell off, and is difficult to replace resin sealant. OBJECTIVE: To observe the effects of traditional resin sealant and atraumatic restorative treatment (ART) glass ionomer-based pit and fissure sealant for the young children. METHODS: Randomized comparison method was used to compare ART glass ionomer-based pit on molars of one side with resin sealant on the opposite side in 89 3-year-old children. RESULTS AND CONCLUSION: The retention rates of ART glass ionomer sealant after 6 and 18 months were significantly lower than those of resin sealant (P < 0.05). The caducous position of ART gliass ionomer sealant was the second deciduous molar of the lower mandible, but the caducous position of resin sealant was the second deciduous molar of the upper mandible. The secondary caries rate of ART glass ionomer sealant was significantly lower than that of resin sealant at 6 months. No significant difference was determined between groups at 18 months. These suggest that ART glass ionomer pit and fissure sealant has lower drop-out rate, simple operation and low cost with excellent caries-preventing effect. Since it is economically superior to resin sealant, the method is worth popularizing in caries-preventing projects. Related Articles | Metrics

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Clinical application of repairment of negative pressure therapy in the management of soft tissue defects after trauma Liu Chen-he, Zhang Yong-hong, Li Dong, Guo Xiang-hong 2011, 15 (38):  7170-7174.  doi: 10.3969/j.issn.1673-8225.2011.38.033 Abstract ( 287 )   PDF (1671KB) ( 520 )   Save BACKGROUND: The main clinical treatments of refractory wounds and traumatic soft tissue defects are traditional surgical treatment for drugs and vacuum sealing drainage (VSD) technology, but the two technologies are obviously not enough. OBJECTIVE: To investigate the application of repairment of negative pressure therapy (RNPT) on soft tissue defects after trauma. METHODS: Sixty cases of traumatic soft tissue defects were randomly divided into 2 groups: Traditional treatment group (Conventional dressing therapy) and RNPT group (Isino negative pressure wound treatment instrument). As the wound clinical evaluation criteria, the treatment efficacy scores were recorded during the dressing time at the end of each treatment cycle or after treatment cycle. RESULTS AND CONCLUSION: Compared with the conventional treatment group, RNPT treatment group could promote injury wound healing, reduce the local edema and stimulate the granulation tissue formation. Furthermore, this technology could also reduce the workload of health care and alleviate the sufferings of the patients which could provide a good condition for the second phase of the wound repair surgery. Related Articles | Metrics

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Burst release and control of the delivery system of protein/peptide drug loaded poly(lactic-co-glycolic acid) microspheres Zhao Xian-ying, Gao Ji-ning, Su Yong-ping, Liu Yi-min, Xiao Xiang 2011, 15 (38):  7177-7180.  doi: 10.3969/j.issn.1673-8225.2011.38.035 Abstract ( 376 )   PDF (1807KB) ( 933 )   Save BACKGROUND: Burst release is key technology that limits the wide application of protein/peptide microspheres. It should be a problem to be solved. OBJECTIVE: To make a detailed introduction about burst release reason, influence factors and reduction methods after analyzing recent progress of burst release and control of protein/peptide drug loaded poly(lactic-co-glycolic acid) (PLGA).   METHODS: Relevant articles in PubMed and CNKI published 1999-01/2010-12 were searched by computer with the key words of “PLGA, peptide, protein, microspheres, burst release, control” in Chinese and English. Articles addressing originally identification, reliability, general analysis, and high correlation were included. Exclusive criteria: repetitive and obsolescent articles. A total of 24 articles were reserved for review. RESULTS AND CONCLUSION: We need to comprehend mechanism of burst release of protein/peptide microspheres to realize enlargement application. Burst release was influenced by multifactors, such as characters of PLGA, preparation methods and preparation parameters. Burst release could be reduced some degree by the control of the above mentioned. It is very important to research of new drugs. Related Articles | Metrics

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Different scaffolds with mesenchymal stem cells to construct tissue engineered ligament in anterior cruciate ligament injury Liu Wei, Chen Shi-rong 2011, 15 (38):  7181-7184.  doi: 10.3969/j.issn.1673-8225.2011.38.036 Abstract ( 299 )   PDF (1439KB) ( 366 )   Save BACKGROUND: Anterior cruciate ligament (ACL) is a strong, dense structure connecting femur and tibia. It is important for forward stability of the knee joint. ACL injury may cause knee joint unstable. If it does not have proper treatment, cartilage, meniscus and other structural may have secondary injury. OBJECTIVE: To review the application of different scaffolds with mesenchymal stem cells (MSCs) in treating ACL injury. METHODS: PubMed database was researched by computer o search articles published from 1950-01 to 2010-11 with key words of “ACL, stem cells, MSC, tendon, ligament”. Totally 103 papers were selected, and 35 articles were included in final analysis. RESULTS AND CONCLUSION: Tissue-engineered ligament constructed with mesenchymal stem cells and scaffolds is successfully used in animal experiements. MSCs can significantly speed up the repair of ligament damage and strengthen the biomechanical properties of healed tissue, but the biomechanical properties of regenerated tissue has not yet reached the level of normal tendon. At the same time, MSCs can promote the healing of the ligament-bone enthesis, prevent failure due to ligament-bone nonunion after ACL reconstruction. To select the appropriate MSCs, scaffold, mechanical stimulation and necessary cytokines is the key to construct tissue engineered ligament. With the development of tissue engineering and scaffold materials, MSCs constructed tissue engineered ligament will be soon introduced from basic research to clinical application. Related Articles | Metrics

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Corrosion and anticorrosion of nickel-titanium arch wires in orthodontics Pan Xiao-jing, Li Zhen-ya, Ran Hai-qun, Qi Yuan-yuan, Liu Bin 2011, 15 (38):  7185-7188.  doi: 10.3969/j.issn.1673-8225.2011.38.037 Abstract ( 356 )   PDF (1688KB) ( 635 )   Save BACKGROUND: Orthodontics with nickel-titanium arch wires often occurs the decrease of mechanical property after clinical application, and seriously affects the effect of clinical therapy. Studies show that corrosion in oral electrolyte is one of the most reasons. OBJECTIVE: To review the research progress on nickel-titanium arch wires in orthodontics recently at home and abroad. METHODS: Literatures related to corrosion of nickel-titanium arch wires in orthodontics from CNKI database, PubMed database and Elsevier (ScienceDirect) database were retrieved. RESULTS AND CONCLUSION: In complex oral environment, temperature, load, fluorinion and other factors can accelerate the corrosion of nickel-titanium arch wires, the property of nickel-titanium arch wires in orthodontics was influenced to some extent, and which reduced the mechanical properties of nickel-titanium arch wires in orthodontics, increased the roughness of surface and then prolonged the course of treatment, and increased the cost of orthodontic treatment. The release of nickel ion of nickel-titanium arch wires in orthodontics reduced its biological safety. Anticorrosion treatment can improve the corrosion resistance of nickel-titanium arch wires; surface treatment technology is mainly applied. However, safe and effective method is seldom at present, the corrosion and anticorrosion on nickel-titanium arch wires in orthodontics is needed to be further deeply studied. Related Articles | Metrics

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Characteristics of nano-artificial bone graft in treatment of tibial plateau fracture Cao Yang, Yuan Zi-ming, Yan Peng, Bi Yun-long 2011, 15 (38):  7189-7192.  doi: 10.3969/j.issn.1673-8225.2011.38.038 Abstract ( 336 )   PDF (1642KB) ( 508 )   Save BACKGROUND: After resetting, tibial plateau fracture always induces great defects of cancellous bone, which requires effective bone graft packing and internal fixation treatment. OBJECTIVE: To explore the application characteristics of nano-artificial bone graft in treatment of tibial plateau fracture. METHODS: We retrieved Wanfang Database (http://www.wanfangdata.com.cn/) for articles concerning nano-artificial bone graft in treatment of tibial plateau fracture published from January 1990 to December 2010. The key words were “nano-artificial bone, tibia, fracture”. A total of 48 articles were searched, and 20 were included. Simultaneously, 42 tibial plateau fracture cases undergoing nano-artificial bone graft combined with internal fixation with locking plate system were retrospectively analyzed. RESULTS AND CONCLUSION: A total of 42 patients were followed up for 6 months to 2 years and 6 months, averagely 15 months. The duration of fracture healing was 3-8 months, averagely 4.2 months. According to Merchant criteria, there were excellent in 39 cases, good in 2 cases, and average in 1 case. Retrieval analysis suggests that nano-artificial bone is a biomaterial prepared by nanometer technique, and is an ideal bone repair material. Artificial bone graft for treatment of tibial plateau fracture can effectively avoid fracture redisplacement and the loss of articular surface height, as well as have characteristics of good biocompatibility, good bone conductibility, small trauma and firm fixation, no rejection or allergic response. Thus, it has extensive application prospect. Related Articles | Metrics

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Research progress and clinical application of sustained-release drugs Aihemaitijiang, Yu Yong-fu, Huang Xiang-zeng 2011, 15 (38):  7193-7196.  doi: 10.3969/j.issn.1673-8225.2011.38.039 Abstract ( 352 )   PDF (1418KB) ( 647 )   Save BACKGROUND: Currently, there are over 40 kinds of slow-release materials available for the production, which are widely used in clinic. OBJECTIVE: To review several important drug carrier materials in the world as well as sustained-release drugs commonly used in clinic. METHODS: A computer search of CNKI and PubMed databases (2000-01/2010-12) were conducted for articles addressing sustained-release drugs. The keywords were “sustained release, drug, biomaterials” in Chinese and English. Meta analysis and repetitive studies were excluded. Finally, 23 articles were included in result analysis. RESULTS AND CONCLUSION: Biodegradable synthetic polymer materials have become highly valued and widely used. Chitosan has become widely accepted for its good performance, as an important carrier of drug delivery; polylactic acid, a biodegradable polymer, plays an important treatment role in drug delivery; fibrin glue with high biocompatibility can effectively delay the drug release, which is widely used in many clinical areas. Related Articles | Metrics

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Sustained-release anti-tumor agent in interventional treatment of liver cancer Pan Yan-kang, Huang Min, Liu Yu-heng 2011, 15 (38):  7197-7200.  doi: 10.3969/j.issn.1673-8225.2011.38.040 Abstract ( 336 )   PDF (1187KB) ( 462 )   Save BACKGROUND: Direct injection of sustained-release chemotherapy provides a new way to tumor treatment. OBJECTIVE: To evaluate the application of sustained-release anti-tumor agents in liver cancer and to find a reasonable treatment. METHODS: A computer based search of relevant articles published 1993-01/2010-12 were retrieved by using the keywords of “liver cancer, implantation of chemotherapy, sustained release implants, chemicals” in Chinese and English. Repetitive articles and Meta analysis were excluded, and finally 29 articles were included in result analysis. RESULTS AND CONCLUSION: Direct injection of sustained-release chemotherapy improves local tumor drug concentration and reaction time, and reduces or avoids systemic chemotherapy-induced common side effects, providing a new route of administration. Direct injection of sustained-release chemotherapy also relieves the pain of advanced cancer patients, bringing a new hope. Sustained-release anti-tumor agents can be used as an ideal slow-release implant in the chemotherapy drugs used in the treatment of liver cancer. Related Articles | Metrics

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Changes in inflammatory factors and intervention after coronary stent implantation Yu Ji-xi 2011, 15 (38):  7201-7204.  doi: 10.3969/j.issn.1673-8225.2011.38.041 Abstract ( 374 )   PDF (1281KB) ( 337 )   Save BACKGROUND: The severity of inflammatory response is obviously correlated with restenosis after coronary stent implantation. Medical workers attempt to find new ideas for the prevention of stent restenosis and improve the quality of treatment. OBJECTIVE: To evaluate the clinical prospects and value of various interventions and monitoring tools in the treatment of inflammatory response after coronary stent implantation. METHODS: An electronic search of EMbase (1980-01/2011-05), MEDLINE (1966-01/2011-05), Chinese Biomedical Literature Database (CBM, 1978/2011-05) and CNKI was performed for relevant articles by using the keywords of “Coronary stent, inflammatory cytokines, inflammation, CRP, restenosis” in Chinese and English. RESULTS AND CONCLUSION: The clinical trials showed that the inflammatory response after stent implantation significantly increased. Inflammatory responses were decreased to a great extent by using sirolimus-eluting stents added with dexamethasone, celecoxib, and rosuvastatin. Animal studies found that the use of sirolimus-eluting stents could reduce neointimal formation of stent segments and inflammatory area. A variety of interventions can reduce the inflammatory response after stent implantation to reduce long-term restenosis; it can be used to further improve the efficacy with clinical observation. Related Articles | Metrics

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Clinical application of artificial joint materials Zhao Yan 2011, 15 (38):  7205-7208.  doi: 10.3969/j.issn.1673-8225.2011.38.042 Abstract ( 317 )   PDF (1767KB) ( 443 )   Save BACKGROUND: Currently, studies about artificial joint materials have achieved remarkable results, but there are still some problems. OBJECTIVE: To review the clinical application and progress of artificial joint biomaterials. METHODS: A computer-based search of VIP database (2000-01/2010-10) was performed to retrieve articles regarding clinical application of artificial joint materials using the keyword of “artificial implant materials”. RESULTS AND CONCLUSION: Regeneration of bone defects has been an important issue in bone research. Currently, the main treatments are autologous bone graft, allograft and artificial bone graft. Repair of bone defects with artificial materials avoids the pain of patients suffering from autologous transplantation, complications and immune rejection due to allogeneic transplantation. But, non-toxic alternative materials are necessary with good cell compatibility and tissue compatibility. Related Articles | Metrics

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Effects of different dual antiplatelet therapies periods on patients with coronary heart disease treated by firebird stents Guo Yu-jie, Wei Jin-ru 2011, 15 (38):  7209-7212.  doi: 10.3969/j.issn.1673-8225.2011.38.043 Abstract ( 300 )   PDF (1347KB) ( 314 )   Save BACKGROUND: The stent thrombosis has a direct impact on the immediate and long-term outcomes following drug eluting stents implantation. OBJECTIVE: To evaluate the effects of different dual antiplatelet therapies periods on the incidence of cardiovascular adverse events in patients with coronary heart disease treated by Firebird stents METHODS: A total of 1 107 consecutive patients with coronary artery disease who received Firebird stent implantation were selected. These patients were divided into three groups based on the time of applying asprin and clopidogrel. Major adverse cardiac events (MACE), drug adverse effect and host response to materials were recorded. RESULTS AND CONCLUSION: 1 059 cases with 1 431 stents were followed up for 7-59 months, and clinical follow-up rate was 95.7%. Rate of MACE occurrence in the group of applying asprin and clopidogrel over 6 months (4.4%) were much lower than other groups (8.9% and 7.7%), there was significant difference among these groups (P < 0.05). Rate of non-fatal myocardial infarction, heart fail, target vessel revascularization and bleeding occurrence in the group of applying asprin and clopidogrel over 6 months were much lower than other groups, there was significant difference among these groups (P < 0.05 or < 0.01). There was no host response to materials in the three groups. The clinical follow-ups showed that the group of applying asprin and clopidogrel until 12 months has a definite clinical efficacy in the patients with coronary artery disease who received Firebird stent implantation, which could reduce the occurrence of MACEs. Related Articles | Metrics

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Nickel-titanium alloy self-expanding Wingspan stent in treatment of intracranial symptomic artery stenosis: One-year follow-up of 13 cases Lou Ping, Lu Hai-bin, Li Qiang 2011, 15 (38):  7213-7216.  doi: 10.3969/j.issn.1673-8225.2011.38.044 Abstract ( 422 )   PDF (1465KB) ( 362 )   Save BACKGROUND: Gateway-Wingspan stent system was certified by the U.S. FDA in 2005 as a nickel-titanium alloy self- expanding stent for the treatment of symptomatic artery stenosis, which was approved to be applied formally in China in 2007. OBJECTIVE: To evaluate the safety and short-term effect of endovascular implantation of nickel-titanium alloy self-expanding Wingspan stent for symptomatic artery stenosis. METHODS: Totally 13 patients with 18 lesions diagnosed as symptomatic artery stenosis were treated with endovascular Wingspan stent based on the Gateway saccule self-expansion. The vascular stenotic lesions involved middle cerebral artery in 11 cases, internal carotid artery in 4 cases, vertebral artery in 2 cases, and basilar artery in 1 case. The length of vascular stenotic lesions was 5-15 mm with a mean incidence of (85.3±10.0)%. RESULTS AND CONCLUSION: All of the 18 stents in the 13 patients were placed successfully in one implantation, accounting for 100%. The stenosis residue was (30.5±12.0)% immediately after implantation; after 12 months follow-up, there was no stroke attack or transient cerebral infarction. The vascular angiography showed no stenosis. After stent implantation, there was no arterial dissection, tear of arterial intima, and acute thrombosis in 13 cases. The stents showed no displacement or rupture. One case appeared to have hypotension and one case had ecchymoma within 3 days after stent implantation, and the symptoms disappeared after treatment. The experimental findings demonstrate that endovascular implantation of nickel-titanium alloy self-expanding Wingspan stent is a safe and effective treatment for intracranial symptomatic artery stenosis, with good short-term efficacy. Related Articles | Metrics

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Expanded mastoid area flap and rib cartilage framework for auricle reconstruction in 46 cases Yu Guo-jun, Feng Bi-zhao, Wang Guang-jun, Wang Yi-bing 2011, 15 (38):  7217-7220.  doi: 10.3969/j.issn.1673-8225.2011.38.045 Abstract ( 288 )   PDF (1339KB) ( 675 )   Save BACKGROUND: There are many materials for auricle reconstruction that are mainly divided into two kinds: artificial materials and autologous tissues with their own advantages and disadvantages. OBJECTIVE: To retrospectively analyze the clinical effect and complications of auricle reconstruction with rib cartilage and expanded mastoid area flap. METHODS: Forty-six patients who would receive auricle reconstruction were selected in Department of Burn, the First People’s Hospital of Huaian City. Auricle reconstruction was taken with rib cartilage framework that was coved with expanded mastoid area flap. Effect and complications of operations were observed. RESULTS AND CONCLUSION: All operations succeed in 46 cases. In all the patients, appearance of auricle was vivid, oto-cranial angle was limpid and effect of operation was satisfactory. Three months after operation, the difference was indistinctive in oto-cranial angle, length and height of auricle between reconstruction auricle and uninjured side auricle (P > 0.05). These indexes had no difference between 3 months and 1 year after operation (P > 0.05). It is indicated that expanded mastoid area flap and rib cartilage framework for auricle reconstruction has a higher safety and better operative effects. Related Articles | Metrics