Solubilized Cartilage ECM Facilitates the Recruitment and Chondrogenesis of Endogenous BMSCs in Collagen Scaffolds for Enhancing Microfracture Treatment.

Articular cartilage has very poor intrinsic healing ability and its repair remains a significant clinical challenge. To promote neocartilage regeneration, we fabricated two collagen (Col) scaffolds functionalized with a porcine decellularized extracellular matrix (dECM) in the forms of particle and solution named pE-Col and sE-Col, respectively. Their differences were systematically compared, including the biochemical compositions, scaffold properties, cell-material interactions, and cartilage regeneration. While it is demonstrated that both forms of dECM could enhance the cell recruitment, proliferation, and chondrogenesis of bone marrow stem cells (BMSCs) , better performance was seen in the sE-Col group, which could quickly provide a more favorable chondrogenic microenvironment for endogenous BMSCs. The superiority of sE-Col was also proved by our study, which showed that the sE-Col scaffold achieved better structural hyaline-like neocartilage formation and subchondral bone repair compared to the pE-Col scaffold, according to the gross morphology, biological assessment, and micro-CT imaging analysis. Together, this study suggests that the sE-Col scaffold holds great potential in developing the one-step microfracture-based strategy for cartilage repair and also reminds us that despite dECM being a promising biomaterial in tissue engineering, the optimization of the proper processing methodology would be a crucial consideration in the future design of dECM-based scaffolds in articular cartilage regeneration.