3D printed cell-laden collagen and hybrid scaffolds for in vivo articular cartilage tissue regeneration

Current surgical treatments for osteochondral injuries include chondrocyte transplantation, osteochondral grafts, and bone marrow stimulation. Despite these approaches, repaired tissues often show limited regeneration resulting in fibrocartilage formation with poor mechanical properties. To overcome these shortcomings, a regenerative cell-laden scaffold therapy is a promising treatment option. In this study, we propose a three-dimensional (3D) micro-sized mesh structure using a cell-laden collagen bioink. To achieve the optimal cell-printing condition for the fabrication of cell-laden collagen structure, porous mesh collagen scaffold (PMCS) were assessed for the mechanical properties, printability and cell viability analysis. In vivo regenerative effects of PMCS were compared to the injecting hydrogel without pores (non-porous collagen scaffold (NPCS)), collagen/poly(ε-caprolactone) (PCL) hybrid scaffold (CPHS)), and pure PCL scaffold (PPS). The porous mesh-structured/cell-laden collagen scaffold (PMCS) showed significantly enhanced cartilage regeneration in vivo compared to other conditions.