Human stem cells – sources, sourcing and in vitro methods

Abstract Stem cells are an important subject of research, and are increasingly used in the treatment of various diseases. Due to the development of advanced in vitro techniques, they have become an integral part of modern medicine. The sources of human stem cells are primarily bone marrow and adipose tissue, although non – embryonic stem cells are also scattered throughout the body. Notably, recent research has focused on stem cells found in the oral cavity, both in the dental pulp and oral mucosa. Furthermore, isolation of stem cells from umbilical cord blood is also becoming increasingly popular, while wharton’s jelly and amniotic fluid also seem to be an interesting source of stem cells. The safety and efficacy of stem cells use can be established by animal studies, which are a key element of preclinical research. Mouse, rat and pig models allow for testing of stem cell therapies. Recent studies primarily use mesenchymal stem cells such as mouse – adipose derived mesenchymal stem cells and mouse and rat hematopoietic stem cells. Great hope for future therapies is the use of bioengineering to program cells into induced stem cells, which have the biggest ability for differentiation and transdifferentiation, which carries no risk of teratogenesis. Stem cells are used in many areas of medicine, especially in regenerative medicine, with a growing interest in orthopedics and in the treatment of heart failure. Mesenchymal stem cells are the most used stem cell type, which despite their limited ability to differentiate, give great therapeutic results, mainly due to their immunomodulating effect. Recent studies have even shown that the use of mesenchymal stem cells may be useful in the treatment of COVID-19. Moreover, Research on the use of mesenchymal stem cells in the treatment of Crohn’s disease, acute-graft-versus-host disease and type I diabetes are also promising. The aim of the current review is to present and systematize current knowledge about stem cells, their use and related in vitro research. Running title: Research and use of human stem cells