IntroductionMesenchymal stem/stromal cell (MSC)-based therapies in cartilage repair and osteoarthritis (OA) treatment have gained attention. Recently, there has been increasing evidence to suggest that MSCs secrete a wide range of trophic factors to modulate the injured tissue environment. Extracellular vesicles (EVs) have been suggested to explain the positive and sometimes curative effect, through the paracrine stimulation of the resident progenitor cells to aid in repair. ObjectivesTo give a narrative review of the current evidence for MSC-derived EV’s potential therapeutic effects and future perspectives for the treatment of OA. MethodsA literature search was conducted using the MEDLINE databases in November 2023. A total of 24 animal studies describing EV, including exosomes utilized in cartilage and OA treatments were identified and analyzed. ResultsPreclinical animal studies indicated that EVs could enhance the therapeutic effects for the treatment of OA, although the purification methods for EVs and their cell sources would be highly relevant to therapeutic efficacy. In contrast, there have been no published clinical studies regarding EVs for the treatment of OA, and thus, properly controlled clinical trials and regulations are essential steps in future clinical applications. ConclusionsThe current evidences suggest that the administration of MSC-derived EVs into damaged joints could effectively reduce cartilage loss and alleviate the progression of OA. In contrast, there are still several potential problems to be solved, including their classification, safety and toxicity in clinical use, as well as optimal dosage and frequency for human administration.

IntroductionPeriostin, a matricellular protein, has emerged as a potential biomarker for anterior cruciate ligament (ACL) injury and has been associated with cartilage degeneration and the development of post-traumatic osteoarthritis (PTOA). ObjectivesThis review aims to comprehensively examine and synthesize the existing literature concerning the role of Periostin in the aftermath of ACL injury, particularly its involvement in subsequent cartilage degradation processes within the knee joint. MethodsConducting a scoping review, we systematically searched Medline, Scopus, and Embase, focusing on human and animal studies investigating Periostin in the context of ACL injury or PTOA. ResultsAnalysis of Periostin expression in human synovial fluid and ACL tissue reveals distinctive temporal profiles, with peak levels observed at a minimum of 1 month post-ACL injury. In vitro data suggests that injured ACL tissue promotes Periostin expression in human chondrocytes. Animal studies demonstrate that recombinant Periostin application leads to increased cartilage degeneration, potentially mediated by enhanced Wnt signaling and MMP-13 expression. Conversely, Periostin knockdown studies indicate a mitigating effect on cartilage degradation. ConclusionsPeriostin exhibits robust associations with biomarkers of cartilage degeneration in humans and progression of osteoarthritis in animals. However, the precise impact of Periostin in the context of ACL injury and its potential causal relationship with the onset of PTOA remain uncertain.