Stem Cell Therapy: Past, Present, and Future Aspects

Background/Objectives: Stem cells with the ability to differentiate into other cell types and self-renewal afford a powerful apparatus for the healthcare system to replace and rejuvenate damaged tissues and organs in the treatment of various diseases. For the last few decades, stem cell therapy (SCT) has evolved from being an experimental approach to a recognized clinical treatment. SCT and regenerative medicine have garnered tremendous attention and become prominent tools, especially in treating chronic and acute disease and addressing organ failures, and in their repair and replacement, which are directly associated with human health, life, and longevity. Methods: In this review, after providing a brief history and need for the SCT, the employed delivery techniques utilizing various biomaterials, as well as recent developments in nanotechnological methods, are presented. It is focused on the current literature for the recent progress of stem cell therapy and tissue engineering for the application fields in neurological, ophthalmological, cardiovascular, orthopedic, and oncology, followed by the challenges associated with their applications. Results: In addition to safety concerns, challenges such as uncontrollable differentiations, genetic and epigenetic instability, limited cell survival and integration, immunological rejections, scaling and manufacturing drawbacks, as well as unpredictable behaviors and clinical limitations were reviewed. Conclusions: Future aspects with respect to regenerative medicine and tissue engineering, gene editing and personalized therapies, immunomodulation and anti-inflammatory applications, as well as neuroregeneration and treatment of neurodegenerative disorders are reflected.