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BACKGROUND:Accumulative evidence supports that co-culture technology can be applied to construct the tissue-engineered cartilage with excellent biological characters. OBJECTIVE:To elaborate the co-culture concept and conclude and analyze seed cell sources, cel mixed ratio, spatial y-defined co-culture models and biomaterials in co-culture systems to conclude and analyze the biological characters of tissue-engineered cartilage, and to prospect progression of co-culture systems in cartilage tissue engineering. METHODS:The first author retrieved the databases of PubMed, Web of Science, and CNKI for relative papers published from January 1976 to May 2016 using the keywords ofco-culture, co-culture systems;articular cartilage, chondrocytes, mesenchymal stem cells;tissue engineering, articular cartilage tissue engineeringin English and Chinese, respectively. Finally 60 literatures were included in result analysis, including 1 Chinese and 59 English articles. RESULTS AND CONCLUSION:Co-culture technology emphasizes the role of microenvironment in terms of various physical, chemical and biological factors in the cell processing. In cartilage tissue engineering, co-culture systems contribute to maintain the viability and natural cell phenotype of chondrocytes and induce cartilage differentiation of mesenchymal stem cells. In addition, co-culture technology provides a novel way for cartilage tissue engineering to overcome the shortage of chondrocytes and repair injury to the cartilage-subchondral bone. However, the mechanisms of cell-cell interaction in co-culture systems still need to be explored in depth, so as to optimize the co-culturing conditions and construct perfect tissue-engineered cartilage.
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BACKGROUND:At present, a variety of extracel ular matrix-derived scaffolds have been successful y applied for cartilage tissue engineering in experiment and clinical practice. OBJECTIVE:To summarize the application and research status of extracel ular matrix-derived scaffolds in cartilage tissue engineering. METHODS:A computer-based online search in PubMed, CNKI, CqVip and WanFang databases was performed using the keywords of“tissue engineering, cartilage, extracel ular matrix, scaffolds”in English and Chinese, respectively. A total of 1 140 literatures were retrieved, and final y 65 eligible literatures were included. RESULTS AND CONCLUSION:In terms of the components, extracel ular matrix-derived scaffolds are divided into monomeric natural polymers, mixed natural polymers, natural polymers compositing with synthetic polymers as wel as acel ular extracel ular matrix-derived materials. Extracel ular matrix-derived scaffolds hold good biocompatibility and degradability, and can promote proliferation and differentiation of choncrodytes;therefore, they as good bionic scaffolds have been applied for cartilage tissue engineering in clinical practice, However, poor mechanical properties and difficulty to molding should never be ignored. Further research should focus on improving the preparation technology by combining synthetic materials with extracel ular matrix-derived scaffolds for cartilage tissue engineering.
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Objective:To investigate the regulatory mechanism of LBP on T lymphocytes excessive apoptosis and the mRNA expression of apoptotic genes in aged rats Methods:T lymphocyte apoptosis and the expression of pre apoptotic and anti apoptotic genes (Fas, FasL, TNFR1, Bax, Bcl2 and TNFR2) from young rats and old rats treated with or without LBP were studied using flow cytometry and fluorescence real time quantitative RT PCR Results:LBP could effectively downregulate the percentage of T cell apoptosis in aged rats At the same time LBP also downregulated the transcription level of TNFR1 gene and upregulated the transcription level of Bcl 2 in T cells from old rats Conclusion:The T cell excessive apoptosis in old rats could be effectively downregulated with LBP, by the by of decreasing the expression of pro apoptotic gene and enhancing the expression of anti apoptotic gene