Abstract

Three-dimensional (3D) printing technology, has achieved good results in articular cartilage damage repair, yet regeneration of hyaline cartilage similar to native cartilage and effectively performing clinical transformation remain challenging. In this study, we used 3D bioprinting technology to add chondrogenic progenitor cells (CPCs) and fibronectin (FN) to an alginate/gelatin/hyaluronic acid (Alg/Gel/HA) composite hydrogel. We used this hydrogel to prepare an active biofilm with uniform pores using modified autologous matrix-induced chondrogenesis (AMIC) technology to effectively repair cartilage defects. The Alg/Gel/HA composite hydrogel combined with FN promoted the chondrogenic differentiation of CPCs by upregulating their gene expression of collagen II, SOX9, and especially PRG4. Adjacent biofilm provided adequate mechanical support and architectural integrity, offering a stable postoperative microenvironment for bone mesenchymal stem cells (BMSCs) released from subchondral bone, and ensured that a laminar structure similar to natural hyaline cartilage was regenerated in the rat cartilage defect model. Characteristic cartilage-like lacuna structures and a gradient structure were observed in the AMIC+FN + CPCs group. We developed an effective method to regenerate full-thickness cartilage defects, this biofunctionalized cell-laden biofilm has great potential for application as a supplement to traditional AMIC technology to improve the quality of cartilage regeneration in a relatively feasible way.