encapsulation of rat bone marrow‑derived mesenchymal stem cells (rbmmscs) in collagen type i containing platelet‑rich plasma for osteoarthritis treatment in rat model

Osteoarthritis (oa) is the most common form of degenerative joint disease, affecting more than 25% of the adults despite its prevalence in the elderly population. most of the current therapeutic modalities aim at symptomatic treatment which lingers the disease progression. in recent years, regenerative medicine such as stem cell transplantation and tissue engineering has been suggested as a potential curative intervention for oa. the objective of this current study was to assess the safety and efficacy of an injectable tissue-engineered construct composed of rat bone marrow mesenchymal stem cells (rbmmscs), platelet-rich plasma (prp), and collagen type i in rat model of oa. to produce collagen type i, prp and rbmmscs, male wistar rats were ethically euthanized. after isolation, culture, expansion and characterization of rbmmscs, tissue-engineered construct was formed by a combination of appropriate amount of collagen type i, prp and rbmmscs. in vitro studies were conducted to evaluate the effect of prp on chondrogenic differentiation capacity of encapsulated cells. in the following, the tissue-engineered construct was injected in knee joints of rat models of oa (24 rats in 4 groups: oa, oa + msc, oa + col- lagen + msc + prp, oa + msc + collagen). after 6 weeks, the animals were euthanized and knee joint histopathology exami- nations of knee joint samples were performed to evaluate the effect of each treatment on oa. tissue-engineered construct was successfully manufactured and in vitro assays demonstrated the relevant chondrogenic genes and proteins expression were higher in prp group than that of others. histopathological findings of the knee joint samples showed favorable regenerative effect of rbmmscs + prp + collagen group compared to others. we introduced an injectable tissue-engineered product composed of rbmmscs + prp + collagen with potential regenerative effect on cartilage that has been damaged by oa.