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BACKGROUND:Induced pluripotent stem cels and mesenchymal stem cels-derived microvesicles have been confirmed in various tissue repairs, which are expected to become more effective and safe therapy for articular cartilage repair. OBJECTIVE:To overal understand the research progress in the use of induced pluripotent stem cels and mesenchymal stem cels-derived microvesicles in articular cartilage repair. METHODS: A computer-based search of PubMed and CNKI was performed by the first author for articles related to stem cel treatment of osteoarthritis published from 2003 to 2015. The keywords were “articular cartilage injury, bone marrow mesenchymal stem cels” in English and Chinese, respectively. In the same field, articles published recently or in authorized journals were preferred. RESULTS AND CONCLUSION:Articular cartilage injury is stil a difficulty in the orthopedics. Many repair methods have been reported, but they al have limitations. Induced pluripotent stem cels and mesenchymal stem cels-derived microvesicles bring a new hope for patients with articular cartilage injury. However, there are stil many problems to be solved, such as extracting and purifying a large amount of cels, proliferation and differentiation potentials, and mechanism underlying cartilage repair.
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BACKGROUND:With the development of fundamental research and clinical research on stem cels, the quantity demanded for stem cels is on the increase, but the relatively out-dated cultivating technology of stem cels restrict the development of the research on stem cels. OBJECTIVE: To review the improvement and innovation of stem cel culture techniques both at home and abroad. METHDOS: In the title and abstract, “stem cels, induced pluripotent stem cels, cultivation, efficiency, reprogramming” in Chinese and English chosen as search terms were utilized to search for the papers related to stem cel culture techniques published from January 2005 to November 2014 in CNKI, VIP, Wanfang and PubMed databases, respectively. In the same field, articles published lately in the authoritative journals were preferred. Totaly 61 articles were searched initialy, and only 39 articles were included in result analysis. RESULTS AND CONCLUSION: The development and improvement of stem cel culture techniques effectively increase the culturing quantity of stem cels, improve the development of basic and clinical studies on stem cels. With the further innovation and breakthrough of stem cel culture techniques, it wil be possible to efficiently culture high-quality stem cels, and the stem cel transplantation tests for human diseases wil be promoted greatly.
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BACKGROUND:Induced pluripotent stem cels have been a hotspot in regenerative medicine research since it was discovered. The clinical application of induced pluripotent stem cels is excessively focused on, but the safety issue is almost ignored. OBJECTIVE:By summarizing the application of induced pluripotent stem cels in animal experiments to analyze the safety problems of induced pluripotent stem cels and their possible reasons in order to lay a foundation for further study and clinical application of induced pluripotent stem cels. METHODS: PubMed database was retrieved by the first author for articles related to the safety of induced pluripotent stem cels published from 2006 to 2014 using the keywords of “induced pluripotent stem cels, safety, immune, immunogenicity, tumorigenicity, cancer, epigenomic, transplantation, generation, reprogramming,genomic, mutation” in English. Related ful texts were got from Cel Press and Nature Databases. Finaly, 28 articles were chosen in result analysis. RESULTS AND CONCLUSION: Safety problems of induced pluripotent stem cels are attracting more and more attentions. Immunogenicity, potential tumorigenicity and epigenetic variation are major risks for the clinical applications of induced pluripotent stem cels. Safety issues of induced pluripotent stem cels mainly come from the reprogramming process. The “integrating genetic manipulation” may lead to a greater risk of tumorigenicity than non-integrating operations. Epigenetic variations emerge in the reprogramming, which are mostly relative to “epigenetic memory” of reprogrammed cels.
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BACKGROUND:There have been a large number of reports on establishing induced pluripotent stem celllines, but studies concerning large-scale in vitro induced differentiation of induced pluripotent stem cels into hematopoietic progenitor cels stil have a lack of in-depth discussion. OBJECTIVE:To develop methods to induce differentiation of induced pluripotent stem cels into hematopoietic progenitor cels in vitro. METHODS: Using the method of infection with lentivirus particles containing four transcriptionfactor genes, which are Oct4, Sox2, Nanog and Lin28, human skin fibroblasts are transduced into induced pluripotent stem cels. In the induced differentiation system, Y-27632, a kind of tyrosine kinase inhibitor-ROCK (p160-Rho-associated coiled-coil kinase), was added, which obviously suppressed apoptosis of cels. Based on conditioned medium with OP9 cels, a differentiation system of inducing induced pluripotent stem cels differentiating into hematopoietic progenitor cels was established. RESULTS AND CONCLUSION:(1) Apoptosis of induced pluripotent stem cels at the first three passages was very obvious, and the cels were difficult in a large-scale expansion. After Y-27632 was added, the apoptosis of embryonic stem cels was obviously inhibited. (2) During embryoid body differentiation, induced pluripotent stem cels cultured in OP9 conditional growth medium differentiated into hematopoietic progenitor celsin vitro that were positive for CD34.