Stem Cells and Cell Therapy: A Critical Review

Abstract: The quality of argumentation has declined on average over the past decades; it is increasingly difficult to distinguish reliable publications from unreliable ones. Drugs and treatments with unproven effects are advertised and recommended to patients. Under these circumstances, the importance of theoretical arguments increases. Stem cells and cell therapy are popular topics in medical and biological literature. Differentiation of exogenous stem cells in various specialized tissues and the replacement of aging and pathologically altered cells is discussed. Some publications exaggerate the healing properties of stem cells with insufficient attention to side effects: oncological, immunological, and infectious. A long list of positive results obtained in experiments of questionable reliability is not indisputable proof of effectiveness and safety. The clinical use of stem cells makes sense only if the cells participate in the formation of adequately functioning tissue or the replacement of damaged cellular elements. Additionally, there should be no significant side effects. There is no satisfactory evidence of compliance with these conditions to date. Alternative action mechanisms (paracrine, trophic, immunomodulatory) are hard to comprehend theoretically, as there is no reason to expect morphologically primitive stem cells to have more developed specialized functions than mature cells. The purpose of stem cells is mitosis, not the synthesis of biologically active substances. This review briefly examines the theoretical and practical aspects of the use of stem cells in certain diseases of the heart, joints, liver, and central nervous system. Perhaps some stem cell therapies provide promising fields for research. The same can be said about mature cells and cell-free preparations with paracrine or other effects of cell therapy. Some areas may turn out to be dead ends. Financing such research diverts funds from promising areas. © Pleiades Publishing, Ltd. 2026.