Stem cells based in vitro models: trends and prospects in biomaterials cytotoxicity studies

Abstract

Advanced biomaterials have produced a significant impact on healthcare by improving the quality of life of people with disabilities. Biomaterials are immensely used in tissue engineering, wound healing applications, and delivery of cancer targeted therapeutics. Biocompatibility and cytotoxicity screening of biomaterials on cell culture systems is the first step before their in vivo testing in animal models and subsequent clinical trials. Direct use of biomaterials on animals may create technical challenges as well as ethical concerns. In order to avoid the ethical concerns of animal use, many non-animal models such as stem cell cultures are being developed and utilized for testing their safety. However, due to several limitations including the inability to recapitulate the complex in vivo microenvironment, the application of stem cell cultures is limited. However, properties of stem cells such as their self-renewal and ability to differentiate into various cell lineages like hepatocytes, cardiomyocytes, and neural cells make them an ideal candidates for in vitro screening studies. Furthermore, the application of stem cells may overcome the challenges associated with the inability to develop a complex heterogeneous tissue using primary cells. Currently, Embryonic Stem Cells (ESCs), Adult Stem Cells (ASCs), and Induced Pluripotent Stem Cells (iPSCs) are being used as in vitro preliminary biomaterials testing models with demonstrated advantages over mature primary cell or cell line based in vitro models. This review discusses the current status and future directions of in vitro stem cell-based cultures and their derivatives such as spheroids and organoids for the screening of their safety before their application to animal models and human in translational research.