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OBJECTIVE@#To prepare customized porous silicone orbital implants using embedded 3D printing and assess the effect of surface modification on the properties of the implants.@*METHODS@#The transparency, fluidity and rheological properties of the supporting media were tested to determine the optimal printing parameters of silicone. The morphological changes of silicone after modification were analyzed by scanning electron microscopy, and the hydrophilicity and hydrophobicity of silicone surface were evaluated by measuring the water contact angle. The compression modulus of porous silicone was measured using compression test. Porcine aortic endothelial cells (PAOECs) were co-cultured with porous silicone scaffolds for 1, 3 and 5 days to test the biocompatibility of silicone. The local inflammatory response to subcutaneous porous silicone implants was evaluated in rats.@*RESULTS@#The optimal printing parameters of silicone orbital implants were determined as the following: supporting medium 4% (mass ratio), printing pressure 1.0 bar and printing speed 6 mm/s. Scanning electron microscopy showed that the silicone surface was successfully modified with polydopamine and collagen, which significantly improved hydrophilicity of the silicone surface (P < 0.05) without causing significant changes in the compression modulus (P > 0.05). The modified porous silicone scaffold had no obvious cytotoxicity and obviously promoted adhesion and proliferation of PAOECs (P < 0.05). In rats bearing the subcutaneous implants, no obvious inflammation was observed in the local tissue.@*CONCLUSION@#Poprous silicone orbital implants with uniform pores can be prepared using embedded 3D printing technology, and surface modification obviously improves hydrophilicity and biocompatibility of the silicone implants for potential clinical application.
Subject(s)
Animals , Rats , Swine , Silicon , Orbital Implants , Endothelial Cells , Porosity , Silicones , Printing, Three-DimensionalABSTRACT
Objective To investigate clinical efficacy of tissue-engineered artificial nerve grafts constructed by acellular nerve grafts combined with adult rat Schwann cell (SC)in the treatment of peripheral nerve injury.Methods SCs were isolated and cultured from the distal nerves of adult Sprague Dawley (SD) rats with 1-week Wallerian degeneration and then combined with acellular nerve grafts to construct tissue-engineered artificial nerve.All rats were divided into acellular nerve graft containing SCs (SC group)and nerve graft containing no cells groups (control group),five animals in each group.At 2-,4-and 8-week after surgery,sciatic function index (SFI)of the affected side was compared between two groups.At postoperative 8 weeks,nerve conduction of sciatic nerve of the injured side,recovery rate of triceps surae wet weight and other relevant parameters were equally compared between two groups.Results In the SC group,SFI of the affected side at 2-,4-and 8-week after surgery,nerve conduction of sciatic nerve at the injured side and recovery rate of triceps surae wet weight at postoperative 8 weeks were significantly better compared with those in the control group (all in P <0.05).Conclusions Combined use of adult rat SCs and acellular nerve grafts effectively repairs peripheral nerve defects and accelerates functional recovery of injured nerves.
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Objective To discuss the effect of bone marrow mesenchymal stem cell (BMSC)as the seed cell transplantation of tissue-engineered artificial nerve in the treatment of peripheral nerve injury. Methods BMSC was obtained from the bone marrow of adult rat through isolation and culture and combined with acellular nerve scaffold to construct ‘tissue-engineered artificial nerve’.After transplantation,rats were divided into two groups,the BMSC +acellular nerve conduit group(BMSC treatment group)and the empty cell conduit group(negative control group)with 5 rats in each group.Sciatic functional index (SFI)of the affected side of rats was compared between two groups at 2 weeks,4 weeks and 8 weeks after the surgery.Moreover,the sciatic conduction,recovery rate of tricipital muscle wet weight and other repair effects of the affected side were compared between two groups at 8 weeks after the surgery.Results The indicators of BMSC treatment group, including SFI assessed at 2 weeks,4 weeks and 8 weeks after the surgery as well as the sciatic conduction and recovery rate of tricipital muscle wet weight assessed at 8 weeks after the surgery,were better than those of the negative control group(all in P <0.05).Conclusions BMSC combined with tissue-engineered artificial nerve of acellular nerve scaffold can effectively promote nerve regeneration and function recovery.
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[Abstract ] Objective To explore the effective method of induction of Schwann cell-like differentiation in bone mesenchymal stem cell (BMSC)of adult rat in vitro.Methods Primary culture of Schwann cell and isolated culture of BMSC were separately conducted.According to different induction methods,the cells were divided into chemical induction group and co-culture induction group.The growth of Schwann cell and BMSC was observed under light microscope.These two kinds of cells were identified by immunofluorescence staining [detecting Schwann cell marker proteins:glial fibrillary acidic protein (GFAP) antibody and S-100 antibody] and flow cytometry.The shape and growth of cells in two groups were dynamically observed by light microscope.The induced differentiation was evaluated with immunofluorescence staining at 3 rd day after co-culture induction in the co-culture induction group and at 4 h and 1 st day after chemical induction in the chemical induction group.Results In the chemical induction group,the BMSC appeared typical Schwann cell-like morphology.The positive expression of GFAP antibody appeared at 4 h after preliminary induction.Meanwhile,the positive expression rate of GFAP and S-100 antibody was (80.9 ± 3.5)% and (59.0 ±1.1 )% at 1 st day after induction.The induced BMSC began to die at 2nd day after chemical induction and most of the induced BMSC had died at 3 rd day after chemical induction.At 3 rd day after co-culture induction,few induced BMSC showed obvious morphological changes like those in chemical induction group.The positive expression rate of GFAP and S-100 antibody was (89.8 ±2.4)% and (80.9 ±1.7)%. The positive expression rate of GFAP and S-100 antibody in the co-culture induction group was higher than those in the chemical induction group and the difference had statistical significance (all in P <0.01).Conclusions The co-culture induction not only has obvious effect on Schwann cell-like differentiation in BMSC,but also promotes the survival and proliferation of BMSC.Thus,co-culture induction is more safe and effective than chemical induction.
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Objective To investigate the changes in morphology and senescence-associated markers of the marrow-derived cardiac stem cells (MCSCs) from rats at different ages and to explore the impacts of age on proliferation, survival and differentiation of MCSCs. Methods With single-cell cloning culture, MCSCs were selected from the bone marrow of young, adult and aged male SD rats respectively. Ultrastructural changes of the cells were viewed under a transmission electron microscope.The senescence-associated changes were examined with SA-β-galactosidase staining and reactive oxygen species(ROS) staining. Distribution of cell cycle of MCSCs from different age groups was evaluated with flow cytometric analysis. Rates of the survived and apoptotic cells were determined by Annexin V/PI double-labeled flow cytometric analysis and Hochest33342 staining. Differentiation of the MCSCs toward cardiomyocytes was induced with BMP-2. Expression of cardiac transcription factors and cardiac specific genes of the cells after induction were examined with RT-PCR. CTnT expression of the cells also be examined with immunocytochemistry. Results The nucleus/plasma ratio of the cells from aged rats decrease and there are some myelin bodies in the cells of aged group. With increasing of age, the MCSCs in S+G2/M phase reduce, while β-galactosidase-positive cells and ROS-positive cells increase. Survival rate of the cells from aged rats is lower than that of the cells from young rats. At four week after induction with BMP-2, expression of Nkx2.5, GATA-4, cTnT mRNA and Cx-43 mRNA of the cells of young group increase significantly. In adult and aged group, expression of the cardiac transcription factors and cardiac specific genes is lower than that of the cells in young group. In immunocytochemical staining, cTnT expression of the cells in young group is stronger after induction with BMP-2. As compared with that of the cells in young group, cTnT expression of the cells in aged group is weak after induction. Conclusion With increasing of age, MCSCs show senescent changes, including their abilities of proliferation, survival and differentiation toward cardiomyocytes decrease.
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The low survival rate of stem cells in the ischemic myocardium microenvironment is the bottle neck in treating ischemic diseases with stem cell transplantation.It is able to increase anti-apoptotic ability of the stem cells and promote their effective differentiation towards myocardial cells directly and indirectly by pretreating the stem cells with cytokines,drugs or chemical compounds,or modifying gene expression to promote cell adhesion,survival or angiogenesis for repairing ischemic myocardium and improving heart function after transplantation of the stem cells.