Mesenchymal Stem Cell-Enriched Hydrogels for the Treatment of Knee Joint Disorders: A Systematic Review

The knee is a complex joint that can be harmed by injuries including osteochondral defects and degenerative diseases such as osteoarthritis (OA). In this context, one of the most promising treatments is the use of hydrogels enriched with mesenchymal stem cells (MSC). Therefore, the aim of this study was to perform a systematic literature review to identify the main biological changes caused by MSC-enriched hydrogels for the treatment of osteochondral defects and osteoarthritic knees using in vivo experimental models. This review was carried out between January and June 2023 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), and the SYRCLE risk of bias tool was used to assess study quality. A total of 1254 articles were retrieved from the Embase, Cochrane, Web of Science, PubMed, and Lilacs databases. After sorting the ar7ticles, 11 were included in this work. It is possible to observe that there is heterogeneity of materials used for the hydrogel manufacturing and the use of MSCs from different origins. It is also possible to observe that the groups treated with MSC-enriched hydrogel had smooth cartilaginous tissue surfaces and a higher amount of glycosaminoglycan (GAG) deposition. Also, a higher immunostaining of collagen II, GAG, and aggrecan and lower levels of collagen X and pro-inflammatory cytokines were observed. In conclusion, this review demonstrates that MSC-enriched hydrogels presented very positive effects on the process of cartilage healing. A systematic literature review was conducted to identify the biological changes caused by mesenchymal stem cell (MSC)-enriched hydrogels in the treatment of osteochondral defects and osteoarthritic knees. Out of 1254 retrieved articles, 11 were included in the review. The study found a variety of materials used for hydrogel manufacturing and MSCs from different sources. The groups treated with MSC-enriched hydrogel showed smoother cartilaginous tissue surfaces; increased glycosaminoglycan (GAG) deposition; higher immunostaining of collagen II, GAG, and aggrecan; and lower levels of collagen X and pro-inflammatory cytokines. Overall, the review concludes that MSC-enriched hydrogels have positive effects on cartilage healing.