Adipose-derived regenerative therapies for the treatment of knee osteoarthritis

Knee osteoarthritis is a degenerative condition with a significant disease burden and no disease-modifying therapy. Definitive treatment ultimately requires joint replacement. Therapies capable of regenerating cartilage could significantly reduce financial and clinical costs. The regenerative potential of mesenchymal stromal cells (MSCs) has been extensively studied in the context of knee osteoarthritis. This has yielded promising results in human studies, and is likely a product of immunomodulatory and chondroprotective biomolecules produced by MSCs in response to inflammation. Adipose-derived MSCs (ASCs) are becoming increasingly popular owing to their relative ease of isolation and high proliferative capacity. Stromal vascular fraction (SVF) and micro-fragmented adipose tissue (MFAT) are produced by the enzymatic and mechanical disruption of adipose tissue, respectively. This avoids expansion of isolated ASCs ex vivo and their composition of heterogeneous cell populations, including immune cells, may potentiate the reparative function of ASCs. In this editorial, we comment on a multicenter randomized trial regarding the efficacy of MFAT in treating knee osteoarthritis. We discuss the study’s findings in the context of emerging evidence regarding adipose-derived regenerative therapies. An underlying mechanism of action of ASCs is proposed while drawing important distinctions between the properties of isolated ASCs, SVF, and MFAT.

Key Words: Knee osteoarthritis, Mesenchymal stromal cells, Adipose tissue, Stromal vascular fraction, Micro-fragmented adipose tissue, Regeneration

Core Tip: Adipose tissue products are becoming increasingly popular regenerative therapies for treating knee osteoarthritis. Encouraging results have been demonstrated in numerous observational studies and randomized trials. However, it is important to distinguish among isolated adipose-derived mesenchymal stromal cells (ASCs), stromal vascular fraction (SVF), and micro-fragmented adipose tissue (MFAT) to avoid study heterogeneity and improve the quality of evidence regarding these therapies. Different modes of preparation, cell composition, and physical properties are likely to influence the regenerative function of ASCs. To elucidate which adipose-derived therapy is superior for cartilage regeneration, randomized trials are needed to compare ASCs, SVF, and MFAT as distinct therapies.

• Citation: Epanomeritakis IE, Khan WS. Adipose-derived regenerative therapies for the treatment of knee osteoarthritis. World J Stem Cells 2024; 16(4): 324-333
• URL: https://www.wjgnet.com/1948-0210/full/v16/i4/324.htm
• DOI: https://dx.doi.org/10.4252/wjsc.v16.i4.324