# Osteoarthritis--The Role of Mesenchymal Stem Cells in Cartilage Regeneration
## 5 Conclusions  
OA is the most prevalent joint disease worldwide, especially among the elderly. However, there is no effective treatment for OA. Environmental, metabolic, and inflammatory factors play an essential role in the development of OA's pathogenesis. Non-pharmacological and pharmacological approaches to treating OA are covered in depth in this article. The primary treatment goals for OA are to reduce pain and slow or halt the disease's progression.  
Joint replacement is the only treatment alternative to pain medication for severe osteoarthritis. Although joint replacement is an effective treatment for symptomatic end-stage osteoarthritis, the results may be unsatisfactory due to developments in implant technology.  
Innovative techniques for treating OA are available thanks to developments in cell-based therapy. It is a prominent topic in regenerative medicine because of its ability to mend cartilage and regulate the immune system. Cellular therapy techniques for OA may benefit from the multipotency, self-renewal, and immunomodulatory characteristics of MSCs, and their easy availability and isolation, according to numerous preclinical and clinical investigations. Bone marrow and AD-MSCs are the most commonly used MSC sources, although many studies investigate their potential for cartilage regeneration when using MSCs. In general, they have exhibited promising outcomes in cartilage repair and the treatment of OA.  
A potential treatment option for OA of the knee joint is the application of MSCs directly to the affected area. Studies that are well-designed and have enough follow-up are the ones that show positive results.  
Positive outcomes from preclinical and clinical trials suggest that medications produced from MSCs could be used to treat OA. However, this technique presents numerous challenges, necessitating the creation of standardized remedies before their therapeutic recommendation.  
The physiological characteristics and cellular activities of MSCs in vitro and in vivo, including immune regulatory processes and the differentiation role of key mediators, are not well understood. Cell culture conditions, cell density, timing and location of MSCs transplantation, and MSCs pretreatment all affect MSCs therapeutic efficacy in both preclinical and clinical studies.  
To limit immunological rejection and achieve the appropriate amount of MSCs, the collection, delivery, and preservation of a patient's stem cells must be thoroughly investigated.  
Given that MSCs are multipotent cells with a high capacity for cell proliferation and differentiation and that both autologous and allogeneic MSCs have been used in several studies, the risks associated with tumorigenesis and severe adverse immunoregulatory responses should be further evaluated in preclinical and clinical trials.  
To maximize the potential of MSCs in OA therapy while avoiding the adverse consequences, these issues should be elucidated correctly in future studies.  
Conceptualization, R.G. and L.A.M.; methodology, R.G. and L.A.M.; software, A.C. and M.-A.B.; validation, E.R., R.G. and L.A.M.; formal analysis, I.-I.R. and I.R.M.; investigation, I.-I.R. and L.A.M.; resources, A.C.; data curation, L.A.M., R.G. and M.-A.B.; writing--original draft preparation, R.G. and L.A.M.; writing--review and editing, L.A.M. and E.R.; visualization, I.R.M. and A.C.; supervision, E.R. and L.A.M.; project administration, E.R. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.