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Objective:To explore the problems of seed cells and biological scaffolds in spinal cord tissue engineering, and review the recent experimental research. Methods:Related literatures were searched in CNKI, Wangfang data, PubMed and Web of Science from establishment to March, 2021, and the problems and progress of seed cells, biological scaffolds and their combination were reviewed. Results:The problems of seed cells are carcinogenicity, immune rejection, ethics, low survival rate and differentiation rate after transplantation, and current researches focus on exploring new cell types, gene transfection, cell co-transplantation and pretreatment before transplantation. The problems of biological scaffold are that a single material selection cannot meet different needs, and the traditional technology cannot simulate the internal structure of spinal cord well. There were more researches focusing on new composite materials and new technology. The core problem of their combination is that the effects of different cell and scaffold combinations are different, and the current researches are mostly devoted to the continuous exploration of suitable composite mode, and try to introduce biological agents and other factors. Conclusion:Spinal cord tissue engineering has the potential to completely change the therapeutic pathway of spinal cord injury. Current experimental researches mainly base on solving the problems of seed cells and biological scaffolds of spinal cord tissue engineering, and further explore the appropriate composite mode of seed cells and biological scaffolds, so as to provide more basic evidence for its clinical application.
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Objective:To observe the adhesion, growth and differentiation of rat neural stem cells (NSCs) on spinal cord acellular scaffold (SCAS) to evaluate its feasibility for spinal cord tissue engineering. Methods:NSCs derived from neonatal Sprague-Dawley rat cerebral cortex were cultured and identified. SCAS were prepared from female Sprague-Dawley rat spinal cord tissues using modified chemical extraction and physical oscillation, and evaluated. The third generation NSCs were planted on SCAS and co-cultured, the morphology of the cells on the scaffold was observed with immunofluorescence, immunohistochemistry and scanning electron microscope. Results:The cultured cells were NSCs, which could proliferate and differentiate. The porosity, water content and enzymatic hydrolysis rates of the prepared SCAS were significantly higher than that of normal spinal cord (|t| > 4.679, P < 0.01). The matrix structure of SCAS was loosely network-like, with few residual nuclei. NSCs adhered and grew well, and differentiated into neurons and glial cells on SCAS. Conclusion:This kind of SCAS shapes multi-channel spatial structure and is suitable for NSCs adhesion, growth and differentiation, which can be used for spinal cord tissue engineering.
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Objective To investigate the feasibility of using PLGA loaded with SD rats' mesenchymal stem cells(rMSCs) transfected with green fluorescent protein (GFP) gene as scaffolds for combinations of molecular, cellular, and tissue-level treatments of spinal cord tissue engineering. Methods rMSCs infected with lentiviral vectors (lv-GFP) were seeded onto PLGA at 8000 cell/cm2, rMSCs-GFP grown under similar conditions on tissue culture plastic as control. The morphology of rMSC-GFP was examined by fluorescence microscopic. The activity of MSCs was detected by MTT assay everyday. Cell cycle analysis was performed after a 3-day culture on PLGA using flow cytometry. The rMSCs-GFP seeded on PLGA was identified by FITC-anti CD34,CD90 and PE-anti CD44, CD106,CD45,CDllb at the third day. Results Fluorescence microscopic examination revealed adherence of the cells to the PLGA surface within 24 h of initial plating. After 3 days, GFP cells were spindle shaped. The difference disappeared at 7 days when cells under both conditions had become confluent Cells proliferated at the same rate on the PLGA surface compared to tissue culture plastic. And cell's cycle was unaffected by the transduction process and seeded on PLGA. Cells maintained their stem cell phenotype as judged by expression of CD90, CD44, CD106 markers,and absence of the hematopoietic marker CD45, CD34. This demonstrated that the transduction and the PLGA surface were not adversely affecting the cells. Conclusions MSCs are a good candidate for spinal cord tissue engineering. Cells continued to express green fluorescent protein(GFP)on a long-term basis,and are compatible with polymer surfaces. Morphology,viability,and growth kinetics were maintained when cells were grown on a poly-lactic-co-glycolic acid(PLGA)polymer scaffold. Therefore,they could make further efforts for combinations of molecular, cellular,and tissue-level treatments of spinal cord tissue engineering.