Regenerative Engineering of Cartilage Using Adipose-Derived Stem Cells

Injury to the articular cartilage occurs commonly in the general population and undergoes minimal spontaneous healing. Traditional methods of cartilage repair provide no long-term cure and are significant causes of morbidity. For this reason, stem cell therapies have recently been investigated for their ability to regenerate cartilage, and the results have been promising. Since the discovery that adipose tissue is a major source of mesenchymal stem cells in 2001, scientists have been studying the use of adipose-derived stem cells (ASCs) for the treatment of various disorders including lesions of the articular cartilage. ASCs hold several advantages over autologous chondrocytes for cartilage repair, including but not limited to their anti-inflammatory effects, their multi-lineage differentiation potential, and their ability to form new cartilage in a defect. Whereas several investigations have been made in in vitro and animal models, there have been surprisingly little clinical studies on the intra-articular use of adipose-derived stem cells, despite their first isolation about a decade and a half ago. The few studies that have been conducted are encouraging. With approval for various stem cell therapies on the horizon, this review seeks to update the clinician and the researcher on the current state-of-the-art use of adipose-derived stem cells for the treatment of cartilage disorders and the regenerative engineering of cartilaginous tissue. Lay Summary Among the most disabling conditions, joint cartilage disorders lack regenerative treatments. Current best alternatives involve major surgery that replaces the entire joint or smaller graft procedures, both with potential short-comings. Stem cells hold tremendous potential for tissue regeneration. Easily expendable fat tissue is an abundant source of stem cells. Recently, there have been a few promising reports in humans on the regenerative effects of fat tissue-derived stem cells in cartilage disorders. This review updates the reader on the current state of art in cell isolation, implantation, and clinical outcomes using fat-derived stem cell-based regenerative therapy for cartilage disorders.