Meniscus is a thin layer of connective tissue in human knees, which helps to maintain the stability of joints and conduct mechanical loads. Meniscus injuries, especially those in the avascular inner zone have a poor healing capability and are associated with the development of osteoarthritis.  

Decellularized meniscus derived extracellular matrix (mECM) hydrogels are promising to promote injured meniscus tissue remodeling and integrative repair. 

Investigations of the long-term efficacy of mECM hydrogel loaded MSCs in pertinent animal models for meniscus repair are rare. 

Recently, a research team led by Dr. YU Yin from the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences, in collaboration with the First Affiliated Hospital of Guangxi Medical University, developed an injectable ECM hydrogel for delivery of bone marrow derived stem cells (BMSCs) to repair the full-thickness meniscus defect in an orthotopic rat model.  

The study was published in Bioactive Materials. 

"Our experiment results indicate that decellularized mECM retain essential proteoglycans and collagens, and significantly upregulate expression of fibrochondrogenic markers by BMSCs compared with collagen hydrogel alone in vitro 3D cell culture," said Dr. YU.

When the injectable ECM hydrogel was applied to an orthotopic model of meniscal injury in SD rat, the histology and micro-CT analysis showed that mECM was superior than Collagen I scaffold in reduction of osteophyte formation and prevention of joint space narrowing and osteoarthritis development. 

These results indicated that mECM hydrogel is a promising carrier to deliver MSCs for long-term repair of meniscus tissue, preventing the development of osteoarthritis. 

Schematic diagram of injectable ECM hydrogel for delivery of BMSCs (Image by SIAT)