Polysaccharide hybrid scaffold encapsulated endogenous factors for microfracture enhancement by sustainable release and cell recruitment

Autologous matrix-induced chondrogenesis improves microfracture (MF), but the lack of functional cells and factors inhibit a curative effect. Here, inspired by the healing process of wounds, we prepared a polysaccharide hybrid scaffold (HDCP) to immobilize endogenous growth factors (eGFs), which were derived from platelet-rich plasma (PRP). Compared with the absence of PRP, the hybrid cross-linking network endowed this scaffold with a denser pore structure, enhanced mechanical properties, and slower protein mass transfer rate, thus ensuring the long-term sustainable release of eGFs. In vitro studies confirmed that HDCP promoted bone marrow mesenchymal stem cell recruitment, proliferation, and chondrogenic differentiation. In vivo implantation indicated that HDCP regenerated a smooth articular cartilage surface with a regular fibrous matrix arrangement structure, and the mechanical strength of the regenerated cartilage considerably improved. The obvious MF enhancement implied that PRP and polysaccharide scaffold hybridization could be used as an implantable matrix for cartilage repair.