ABSTRACT
BACKGROUND: Stem cells are the potentially immortal cells capable of self-renewal, which are essential to the mystery of human development and aging, and are also the core of research for regenerative medicine. OBJECTIVE: To summarize the biological characteristics of embryonic stem cells, adult stem cells and induced pluripotent stem cells, to review the clinical and commercial applications in stem cell therapy and drug screening, and to analyze the problems and prospects in stem cell industry. METHODS: We searched relevant articles about stem cell models in PubMed and CNKI databases during 1995 to 2017 on internet, and took"stem cells, embryonic stem cells, adult stem cells, induced pluripotent stem cells, stem cell therapy, drug screening" as the keywords in English and Chinese, respectively. RESULTS AND CONCLUSION: According to the origin, stem cell models are divided into three types: embryonic stem cells, adult stem cells and induced pluripotent stem cells. Different types of stem cells have their unique biological advantages. Embryonic stem cells can generate all somatic cell types, but the application is limited by ethical disputes. As for adult stem cells, there are the most extensive and in-depth, studies as the well as the most prevalent and mature applications. Induced pluripotent stem cells have similar characteristics as embryonic stem cells, and furthermore their use avoids source restriction, moral and ethical controversies, bringing new opportunities for stem cell application. Stem cell-based cell therapy has shown successful achievement. There have been a few commercial products about adult stem cells-based cell therapy; in the meanwhile both embryonic stem cells and induced pluripotent stem cells are making their way into clinical trials. In addition, pluripotent stem cells hold great promise for the specific drug screening because they enable scientists to establish a variety of cell and disease models in vitro.