Stem cells: Definition, characteristics, classification, sources and ethical approaches
Makaleler > Tam Makale · 2026
Yazarlar: Zeynep Konukcu Mehdılı, Özgün Selim Germiyan, Afig BERDELİ, Yiğit UYANIKGİL
Ege Tıp Dergisi, Uluslararası, 2026, cilt 65, ss 357-368
DOI: 10.19161/etd.1870790
Özet
Aim: Stem cells are undifferentiated progenitor cells characterized by their unique capacity for self-renewal and the potential to differentiate into various specialized cell types under appropriate conditions. These cells are distributed across various biological stages and tissues, including embryonic structures, bone marrow, umbilical cord blood, and adult organs. Through mechanisms such as asymmetric division, stem cells play a central role in maintaining the progenitor pool while facilitating tissue repair and homeostatic regeneration.Materials and Methods: This study classifies stem cells based on two primary criteria: differentiation potential (totipotent, pluripotent, multipotent, oligopotent, and unipotent) and biological origin (embryonic, adult, and fetal sources). Furthermore, the biological characteristics of induced pluripotent stem cells and cancer stem cells are analyzed. The study evaluates specific surface markers- such as CD34, CD133, and CD44-used for identification as well as the internal and external regulators governing symmetric and asymmetric division modes.Conclusions: Stem cells offer revolutionary therapeutic potential in regenerative medicine and tissue engineering for treating degenerative conditions, including leukemia, Parkinson's disease, diabetes, and myocardial injury. Induced pluripotent stem cells technology presents a significant advancement by addressing the ethical concerns associated with embryonic stem cells and reducing the risk of immune rejection through patient-specific applications. However, critical challenges such as the risk of teratoma formation, genomic instability, and potential immune responses remain primary hurdles for clinical translation. To optimize the safety and efficacy of these therapies, comprehensive preclinical research and the development of novel biotechnological strategies are essential.