The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair periph- eral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium su...The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair periph- eral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium suture in the treatment of peripheral nerve injury. This study sought to identify the regeneration law of nerve fibers in the biological conduit. A nerve regeneration chamber was constructed in models of sciatic nerve injury using 2-mm small gap sleeve bridging of a biodegradable biological conduit. The results showed that the biological conduit had good his- tocompatibility. Tissue and cell apoptosis in the conduit apparently lessened, and regenerating nerve fibers were common. The degeneration regeneration law of Schwann cells and axons in the conduit was quite different from that in traditional epineurium suture. During the prime period for nerve fiber regeneration （2-8 weeks）, the number of Schwann cells and nerve fibers was higher in both proximal and distal ends, and the effects of the small gap sleeve bridging method were better than those of the traditional epineurium suture. The above results provide an objec- tive and reliable theoretical basis for the clinical application of the biological conduit small gap sleeve bridging method to repair peripheral nerve injury.展开更多
This study aimed to examine the differences in the morphological properties and proliferation of olfactory ensheathing cells in three-dimensional culture on collagen-heparan sulfate biological scaffolds and in two-dim...This study aimed to examine the differences in the morphological properties and proliferation of olfactory ensheathing cells in three-dimensional culture on collagen-heparan sulfate biological scaffolds and in two-dimensional culture on common flat culture plates. The proliferation rate of olfactory ensheathing cells in three-dimensional culture was higher than that in two-dimensional culture, as detected by an M-I-r assay. In addition, more than half of the olfactory ensheathing cells subcultured using the trypsinization method in three-dimensional culture displayed a spindly Schwann cell-like morphology with extremely long processes, while they showed a flat astrocyte-like morphology in two-dimensional culture. Moreover, spindle-shaped olfactory ensheathing cells tended to adopt an elongated bipolar morphology under both culture conditions. Experimental findings indicate that the morphological properties and proliferation of olfactory ensheathing cells in three-dimensional culture on collagen-heparan sulfate biological scaffolds are better than those in two-dimensional culture.展开更多
AIM： To construct the expression vectors for prokaryotic and eukaryotic human augmenter of liver regeneration （hALR） and to study their biological activity. METHODS： hALRcDNA clone was obtained from plasmid pGEM-T...AIM： To construct the expression vectors for prokaryotic and eukaryotic human augmenter of liver regeneration （hALR） and to study their biological activity. METHODS： hALRcDNA clone was obtained from plasmid pGEM-T-hALR, and cDNA was subcloned into the prokatyotic expression vector pGEX-4T-2. The recombinant vector and pGEX-4T-2hALR were identified by enzyme digestion and DNA sequencing and transformed into E coli JM109. The positively selected clone was induced by the expression of GST-hALR fusion protein with IPTG, then the fusion protein was purified by glutathine s-transferase （GST） sepharose 4B affinity chromatography, cleaved by thrombin and the hALR monomer was obtained and detected by measuring H thymidine incorporation. RESULTS： The product of PCR from plasmid pGEM-T- hALR was examined by 1.5% sepharose electrophoresis. The specific strap was coincident with the theoretical one. The sequence was accurate and pGEX-4T-hALP digested by enzymes was coincident with the theoretical one. The sequence was accurate and the fragment was inserted in the positive direction. The recombinant vector was transformed into E coli JM109. SDS-PAGE proved that the induced expressive fusion protein showed a single band with a molecular weight of 41 kDa. The product was purified and cleaved. The molecular weights of GST and hALR were 26 kDa, 15 kDa respectively. The recombinant fusion protein accounted for 31% of the total soluble protein of bacterial lysate. HALR added to the culture medium of adult rat hepatocytes in primary culture and HepG2 cell line could significantly enhance the rate of DNA synthesis compared to the relevant control groups （P 〈 0.01）.CONCLUSION： Purified hALR has the ability to stimulate DNA synthesis of adult rat hepatocytes in primary culture and HepG2 cells in vitro, and can provide evidence for its clinical application.展开更多
The recovery and reconstruction of central nervous system function after spinal cord injury(SCI)is a worldwide problem.The difficulty lies in the feasibility issue of new axons passing through the injured area and the...The recovery and reconstruction of central nervous system function after spinal cord injury(SCI)is a worldwide problem.The difficulty lies in the feasibility issue of new axons passing through the injured area and the negative effect of scarring after injury.As a biological material,the human amniotic membrane(HAM)has the advantages of protecting nerve growth,inhibiting scar formation,and promoting neovascularization,but its weak physical properties are difficult to apply in treating SCI.In this study,HAMs were first decellularized and then chemically grafted with methacrylic anhydride.Next,the composite was photocrosslinked with gelatin methacrylate to prepare a cross-network biological complex.The final complexes prepared by appeal were used for in vitro and in vivo studies of SCI in rats,separately.In the in vitro experiment,the composite scaffold inherited abundant biological factors from the amniotic membrane and had the physical properties of a hydrogel,thus providing a favorable environment for the growth and development of neurons and blood vessels.In the in vivo experiment,the composite reduced scarring and promoted the growth of new nerves.Overall,the composite scaffolds can stably simulate the extracellular microenvironment in SCI defects,regulate pathological changes,and promote the generation of new neurons.Therefore,decellularized HAM hydrogels are promising biocomposite materials for central nerve repair after SCI.展开更多
基金supported by grants from the National Program on Key Basic Research Project of China(973 Program),No.2014CB542200Program for Innovative Research Team in University of Ministry of Education of China,No.IRT1201+1 种基金the National Natural Science Foundation of China,No.31271284,31171150,81171146,30971526,31100860,31040043,31371210Program for New Century Excellent Talents in University of Ministry of Education of China,No.BMU20110270
文摘The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair periph- eral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium suture in the treatment of peripheral nerve injury. This study sought to identify the regeneration law of nerve fibers in the biological conduit. A nerve regeneration chamber was constructed in models of sciatic nerve injury using 2-mm small gap sleeve bridging of a biodegradable biological conduit. The results showed that the biological conduit had good his- tocompatibility. Tissue and cell apoptosis in the conduit apparently lessened, and regenerating nerve fibers were common. The degeneration regeneration law of Schwann cells and axons in the conduit was quite different from that in traditional epineurium suture. During the prime period for nerve fiber regeneration （2-8 weeks）, the number of Schwann cells and nerve fibers was higher in both proximal and distal ends, and the effects of the small gap sleeve bridging method were better than those of the traditional epineurium suture. The above results provide an objec- tive and reliable theoretical basis for the clinical application of the biological conduit small gap sleeve bridging method to repair peripheral nerve injury.
基金sponsored by the National Natural Science Foundation of China,No. 30570628,30770751 and 81171089
文摘This study aimed to examine the differences in the morphological properties and proliferation of olfactory ensheathing cells in three-dimensional culture on collagen-heparan sulfate biological scaffolds and in two-dimensional culture on common flat culture plates. The proliferation rate of olfactory ensheathing cells in three-dimensional culture was higher than that in two-dimensional culture, as detected by an M-I-r assay. In addition, more than half of the olfactory ensheathing cells subcultured using the trypsinization method in three-dimensional culture displayed a spindly Schwann cell-like morphology with extremely long processes, while they showed a flat astrocyte-like morphology in two-dimensional culture. Moreover, spindle-shaped olfactory ensheathing cells tended to adopt an elongated bipolar morphology under both culture conditions. Experimental findings indicate that the morphological properties and proliferation of olfactory ensheathing cells in three-dimensional culture on collagen-heparan sulfate biological scaffolds are better than those in two-dimensional culture.
基金Supported by National "863" Program of China , No. 2002AA214011
文摘AIM： To construct the expression vectors for prokaryotic and eukaryotic human augmenter of liver regeneration （hALR） and to study their biological activity. METHODS： hALRcDNA clone was obtained from plasmid pGEM-T-hALR, and cDNA was subcloned into the prokatyotic expression vector pGEX-4T-2. The recombinant vector and pGEX-4T-2hALR were identified by enzyme digestion and DNA sequencing and transformed into E coli JM109. The positively selected clone was induced by the expression of GST-hALR fusion protein with IPTG, then the fusion protein was purified by glutathine s-transferase （GST） sepharose 4B affinity chromatography, cleaved by thrombin and the hALR monomer was obtained and detected by measuring H thymidine incorporation. RESULTS： The product of PCR from plasmid pGEM-T- hALR was examined by 1.5% sepharose electrophoresis. The specific strap was coincident with the theoretical one. The sequence was accurate and pGEX-4T-hALP digested by enzymes was coincident with the theoretical one. The sequence was accurate and the fragment was inserted in the positive direction. The recombinant vector was transformed into E coli JM109. SDS-PAGE proved that the induced expressive fusion protein showed a single band with a molecular weight of 41 kDa. The product was purified and cleaved. The molecular weights of GST and hALR were 26 kDa, 15 kDa respectively. The recombinant fusion protein accounted for 31% of the total soluble protein of bacterial lysate. HALR added to the culture medium of adult rat hepatocytes in primary culture and HepG2 cell line could significantly enhance the rate of DNA synthesis compared to the relevant control groups （P 〈 0.01）.CONCLUSION： Purified hALR has the ability to stimulate DNA synthesis of adult rat hepatocytes in primary culture and HepG2 cells in vitro, and can provide evidence for its clinical application.
基金supported by the National Natural Science Foundation of China(No.82371383)。
文摘The recovery and reconstruction of central nervous system function after spinal cord injury(SCI)is a worldwide problem.The difficulty lies in the feasibility issue of new axons passing through the injured area and the negative effect of scarring after injury.As a biological material,the human amniotic membrane(HAM)has the advantages of protecting nerve growth,inhibiting scar formation,and promoting neovascularization,but its weak physical properties are difficult to apply in treating SCI.In this study,HAMs were first decellularized and then chemically grafted with methacrylic anhydride.Next,the composite was photocrosslinked with gelatin methacrylate to prepare a cross-network biological complex.The final complexes prepared by appeal were used for in vitro and in vivo studies of SCI in rats,separately.In the in vitro experiment,the composite scaffold inherited abundant biological factors from the amniotic membrane and had the physical properties of a hydrogel,thus providing a favorable environment for the growth and development of neurons and blood vessels.In the in vivo experiment,the composite reduced scarring and promoted the growth of new nerves.Overall,the composite scaffolds can stably simulate the extracellular microenvironment in SCI defects,regulate pathological changes,and promote the generation of new neurons.Therefore,decellularized HAM hydrogels are promising biocomposite materials for central nerve repair after SCI.
