Mesenchymal Stem Cells in Regenerative Medicine, Possible Applications in The Restoration of Spermatogenesis: A Review.

Infertility is a common clinical condition and about half of the major causes are due to male-related infertility. Pathogenesis of this abnormality is generally undefined; so establishing a proper treatment option is relatively uncertain. In recent years, several evidences demonstrated that mesenchymal stem cells (MSCs) can be a hope for innovative and efficient treatment of male infertility. This study reviews possible applications of MSCs in the restoration of spermatogenesis in male infertility of both humans and animals to suggest new avenues for future clinical practices. Articles published in "PubMed" and "Google Scholar" from January 1, 2000, to August 1, 2023, were investigated by searching items of "mesenchymal stem cells", "cell therapy", "cell transplantation", and, "regenerative medicine" keywords, in addition to the "urology", "andrology", "reproductive medicine", "male infertility", "azoospermia", and "spermatogenesis". The results obtained from the transplantation of MSCs in the treatment of male infertility seemed encouraging and they revealed the safety and efficacy of these cells to recover spermatogenesis; eventhough further stem cell research is still required before recruiting clinical application of MSCs in the treatment of human male infertility. Undertaking more well-defined, standardized, and reproducible protocols and enrolling larger sample sizes during a longer follow-up period can benefit the relevance of MSC transplantation in the restoration of spermatogenesis and treatment of male infertility. It seems that developing and utilizing stem cell transplantations, exosomes, scaffold delivery systems, and three dimensional (3D) culture methods may open a new window to getting more benefits from cell therapy in the treatment of men infertility.