Objective To study bioactivity of microencapsulated peripheral nerve tissue after transplanted into abdominal cavity and analyze the in vivo time-effect relation. Methods Microencap-sulated peripheral nerve tissues were injected into the abdominal cavity of mice. Results Microencap-sulated peripheral nerve could remain intact six months after transplantation. The peripheral nerve cells survived, with normal proliferation function. Conclusions Microencapsulated peripheral nerve tissues can remain bioactivity at least six weeks in vivo. Improved technique of microencapsulation may prolong bioactivity of microencapsulated peripheral nerve tissues and accordingly promote nerve regeneration fol-lowing peripheral nerve injury.

Objective:To evaluate the characteristics of fusion using biomimetic n-HA/PA66 interbody cage with rhBMP-2 and discuss the feasibility of it.Methods:Thirty adult female goats underwent C_(3-4) discectomy and interverbral fusion performed with nHA/PA66 interbody cage without rhBMP-2(n=10).nHA/PA66 interbody cage with rhBMP-2(n=10),autogenous iliac crest bone graft(n=10).X ray was carried out at 4 and12 weeks after surgery to evaluate fusion quality.The goats were killed respectively on the 12th week.Nondestructive biomechanical testing for stiffness,un-decalcified histology were performed.Result:The goats in the n-HA/PA66 with rhBMP-2 group and the autogrft group all showed complete fusion at 12th week.there was no statisti- cally significant differience between the n-HA/PA66 with rhBMP-2 group and the autogrft group upon biomechanics,radiography and histomorphology.Conclusion:The interverbral fusion cage with n-HA/PA66 has good hiocompatibifity and osteoconductive ability and it may be good osteoionductive with rhBMP-2,so it was one ideal interbody fusion cage.

0.05).Conclusion The intervertebral fusion cage of n-HA/PA66 has good biocompatibility and osteo-conductibility.It may be the ideal interbody fusion cage.

Objective To investigate the activity of gastrocnemius muscle after acellular nerve transplantation with microencapsulated peripheral nerve tissue to repair sciatic nerve gap in dogs. Methods Twelve dogs were selected and divided randomly into four groups with three in each. Both sciatic nerves of the dogs in group A were cut and chemically extracted to make acellular nerves. Acellular nerves were transplanted into the dogs of groups B and C to bridge 30 mm sciatic nerve gaps, and additionally microencapsulated peripheral nerve were added in group B. Autograft was used for repairing the defects in group D. The motor function of operated limbs were observed regularly after operation. Six months after operation, motor conduction velocity of the specimens of sciatic grafting nerve segment were observed, and the gastrocnemius muscle of both sides were obtained and performed succinic dehydrogenase (SDH), synaptophysin (SYP) and motor end plate histochemical staining, and sciatic nerve 1 cm from distal end stoma were obtained and underwent Masson, Luxol fast blue and NF200 staining. Results All the dogs in groups B, C and D were involved in the results analysis without loss. Image analysis indicated the optical density and the cross section area of gastrocnemius muscle, area and optical density of synaptophysin, area and optical density of motor end plate in group B showed statistically significant difference compared with those in group C, but no significant difference with those in group D. The results of motor function recovery of operated-limb, electrophysiological examination and morphologic observations of sciatic nerve were all consistent with the detections of gastrocnemius muscle. Conclusion The gastrocnemius muscle may be again innerved by nerve, and the muscle atrophy is significantly alleviated after acellular nerve transplantation with microencapsulated peripheral nerve tissue for repairing sciatic nerve gap. The regeneration of nerve was better after the combined transplantation than only acellular nerve transplantation, so the combination of acellular nerve and microencapsulated peripheral nerve tissue may be a useful substitute of autograft for nerve repair.

There are many kinds of the scaffolds of tissue engineered cartilage, including collagen, polylactic acid hybrid material, chitosan and decellular extracellular matrix. They all have biocompatibility, safety and stable physicochemical property, which indicate good application value in the field of tissue engineering. Moreover, the composite scaffolds are superior to simple scaffold. It is potential scaffold materials that developing into composite materials, biomimetic materials, modified natural materials, intelligent material and nano-technological materials.

It is limited for cartilage tissue to repair its injury. The biological substitution of articular cartilage, namely artificial cartilage, has a good prospect due to the tissue engineering. Biological scaffold material is an important part of tissue engineering cartilage, and therefore, it is significant to explore the progress in biological scaffold materials for the construction of articular cartilage. The main research tendency of recent biological scaffold materials for artificial cartilage is to develop composite, bionic and intelligent materials with good biocompatibility and mechanical functions, through integrated application of surface modification, new construction technology and respective advantages of natural and synthetic materials.

BACKGROUND: Deproteinized bone has three diamensions frame profitting bone cells to adhere to, new capillaries and interstitial cells to enter, osteoblasts to differentiate and extracellular matrix to synthesize. Calcium phosphate cement (CPC) is a new in-ceramic bone cement that can degradate, which has plasticity, no heat production, invariably mechanics intension and porosity.OBJECTIVE: To explore the ability of CPC attaching with human vascular endothelial growth factor (rhVEGF) and recombinant human bone morphogenetic protein-2 (rhBMP-2) in promoting deproteinized osteoarticular allograft to repair osteoarticular defect.DESIGN: Randomly control observation.SETTING: Department of Orthopaedics, the First Affiliated Hospital, Chongqing Medical University.MATERIALS: A total of 42 adult hybridization dogs of both genders and weighing (10±0.5) kg were provided by Animal Center of Chongqing Medical University. RhVEGF was provided by Beijing Boaosen Biotechnology Co., Ltd.; rhBMP-2 by Guangzhou Dahui Biotechnology Co., Ltd.; CPC by Shanghai Ruibang Biotechnology Co., Ltd.METHODS: The experiment was carried out in the Laboratory of Orthopaedics (Municipal Laboratory), Clinical College,Chongqing Medical University from March to September 2006. A total of 36 adult dogs were randomly divided into three groups with 12 in each group, including group A: CPC/rhVEGF/rhBMP-2/deproteinized femoral inferior extremity (DPB)osteoarticular allograft; group B: rhVEGF/rhBMP-2/DPB osteoarticular allograft; group C: simple DPB osteoarticular allograft. The experimental dogs were cut off femur by wire saw from articular surface with 30 mm, then fixed the grafts to broken ends of fractured femur with cross Kirschner wires, drawn down the proximad periosteum and sutured it. At the 4th, 8th, 12th and 16th weeks after operation, the effects were partly assessed by X-ray film examination, histologic examination as well as immunohistochemistry analysis of VEGF and BMP-2, vas capillare analysis by vaso-filling with ink, radionuclide bone imaging examination (ECT) and vitodynamic tests.MAIN OUTCOME MEASURES: At the 4th, 8th, 12th and 16th weeks after operation, the effects were partly assessed by X-ray film examination, histologic examination as well as immunohistochemistry analysis of VEGF and BMP-2, vas capillare analysis by vaso-filling with ink, radionuclide bone imaging examination (ECT) and vitodynamic tests.RESULTS: All 36 rats were involved in the final results. ① From 4th to 16th week after operation, the callus formation in group A was better than that of group B and group C by x-ray film examination. ② Image analysis system displayed that the value of area integration of optical density in group A was obviously higher than that in group B and C about VEGF at the 8th, 12th and 16th weeks, and BMP-2 at the 4th, 8th, 12th and 16th weeks. The difference had statistical significance (P＜ 0.01). ③ The new vessels of grafts in group A were more than those in group B and C, part of those inclined to mature. The difference had statistical significance (P ＜ 0.01). ④ The blood flow of operation side was higher than that of uninjured side after operation, but that in group A was significantly higher than that in group B and C. The difference had statistical significance (P＜ 0.01). ⑤ At the 16th week, the result in group A was significantly higher than that in group B and C (P＜ 0.01).CONCLUSION: The recombinant deproteinized osteoarticular materials have fairly strong ability of new bone formation and vasculogenesis, and can early achieve bone healing, repairing osteoarticular defect and become autologous tissue at last.

OBJECTIVE: To review the outcomes of experiments about vascular endothelial growth factor(VEGF) and the effect of it on bone formation, and to make sure whether VEGF can promote bone formation or not.DATA SOURCES: Electronic data searches were performed to obtain data from the databases of http://www.ncbi. nlm. nih. gov/pubmed and http://www. zglckf.com. DATA SELECZION: Nearly 30 articles about VEGF and the role of VEGF affecting bone formation were selected, regardless of the randomized design,blind method involved in or not.DATA EXTRACTION: These researches proved the structures, biologic properties and expression of VEGF and vascular endothelial growth factor receptor(VEGFR), and showed that VEGF plays an important role in endochondral ossification by promoting angiogenesis, bone turnover and preventing apoptosis of chondrocyte. In intramembranous ossification, absence of cartilage, osteoblasts are likely producing, and responding to, VEGF. VEGF also acts to recruit and activate osteoclasts as well as stimulate osteoblast chemotaxis, differentiation and matrix mineralization. It is debatable whether local application of exogenous VEGF can promote bone repair or not. However, in certain situation such as ischemia, the increase of VEGF locally may promote bone repair.DATA SYNTHESIS: Compared with the control group, VEGF can promote osteogenesis, bone formation and remodeling through the effect of VEGF on endochondral ossification and intramembranous ossification.CONCLUSION: One possible advantage of local VEGF therapy may be its ability to couple angiogenesis with bone formation and remodeling. If we can ultimately apply VEGF to treat osteonecrosis, bone defect and nonunion, we will find a new therapy for these diseases.

Objective To evaluate the effects of glial cell line-derived neurotrophic factor(GDNF) gene-activated matrix(GAM) in bridging rat sciatic nerve defect.Methods The peripheral nerve extracellular matrix was harvested by chemical extraction.GDNF gene-activated matrix was comprised of the extracellular matrix and plasmids encoding GDNF.Ninety adult Wistar rats were randomly divided into three groups: group A(GDNF GAM conduits),group B(extracellular matrix conduits),group C (autografts).At the end of 12 weeks,rats from each group were subjected to walking tract analysis,electrophysiological and histomorphological studies.Results GDNF DNA could be retained in GAM,promoting transgene expression in the sciatic nerve,in GAM,and more importantly,in axotomized neurons in spinal cord for 12 weeks.The number of regenerated axons for the GAM grafts in the distal sciatic nerve was lower than that for autografts(2 117?294 vs 2 474?297) at 12 weeks.The sciatic nerve function index for the GAM grafts was lower than that for autografts [(30.92?2.98)% vs(26.27?2.71) %] at 12 weeks.Conclusion GDNF GAM may be a promising alternative to autografts for repair of rat sciatic nerve.

BACKGROUND: It has been proved that vascular endothelial growth factor 165(VEGF165) and bone morphogenetic protein 2(BMP2) can accelerate the vascularization synergistically.OBJECTIVE:To construct the vectors, pDsVEGF165Red1-N1 and pIRES2-BMP2-enhanced green fluorescent protein(EGFP) followed by co-transfected into HEK 293-T cells,and study their expression and location of VEGF165and BMP2 in the cells.DESIGN: A randomized and controlled experiment.SETTING: National Key Laboratory,Institute of Surgery Research,Daping Hospital,Third Military Medical University.MATERIALS: The experiment was conducted at National Key Laboratory,Institute of Surgery Research,Daping Hospital,Third Military Medical University from September 2002 to March 2004. pcDNA3.1\BMP2 ( gift of Dr.Bostrom, UCLA School of Mediine, Los Angeles,USA).pDsRed1-N1(gift of Pro. Roger Y.Tisen,University of California,San Diego,USA). pUC18/VEGF165,293-T cells(preserved by our Laboratory).METHODS: According to the nucleotide sequence of hVEGF165, the primers were designed.The hVEGF165 gene without stop codon was amplified by polymerase chain reaction (PCR).The fragment digested was cloned into the expression vector pDsRed1-N1.Meantime,the pIRES2-BMP2-EGFP expression vector was constructed.The two plasmids were co-transfected into HEK 293-T cells.The co-expression and distribution of the VEGF165and BMP2 were observed with confocal laser microscopy (CLSM) and detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western Blotting.MAIN OUTCOME MEASURES: Identification of the recombinant plasmids and the expressing mRNA and protein in 293-T cells.RESULTS: The recombinant plasmids were verified correct construction by restriction enzyme analysis, PCR and sequencing. The two genes which were co-transfected could express in HEK 293-T cells.The co-expression of the report genes,RFP and EGFP, were found over the cytoplasm and in the nuclei by CLSM.CONCLUSION: Two report gene expression vectors contain VEGF165 and BMP2 have been constructed successfully, which can be co-expressed in HEK 293-T cells. Thus, they can provide important and convenient tool to study intracellular interaction of VEGF165 and BMP2.