Development of meniscus-inspired 3D-printed PCL scaffolds engineered with chitosan/extracellular matrix hydrogel

Meniscus injuries, usually caused by tears or degenerative processes, impair normal knee function and lead to advanced osteoarthritis. Therefore, with the aim of restoring the normal meniscus function, replacement strategies based on tissue engineering strategies have gained prominence alongside other therapeutic endeavors. Regarding heterogeneity of natural meniscus tissue, ideal scaffold in meniscal engineering should mimic tissue with regard to both tissue architecture and biochemical composition. In this research, polycaprolactone (PCL) scaffolds with different strand spaces were firstly designed and fabricated through 3D-printing process to provide a template and structural support for meniscus regeneration. According to results of physical and mechanical characterizations, 3D-printed scaffolds with strand space of 0.2 mm were modified with chitosan hydrogel containing decellularized meniscus to recapitulate the structure and composition of meniscus extracellular matrix (ECM). The electron microscopy and infrared spectroscopy results demonstrated the successful biomimetic coating of chitosan/ECM hydrogel on scaffolds that subsequently promoted the metabolic activity of cultured human adipose derived stem cells (hASCs). qPCR analysis of ACAN, SOX9, COLL2, and COLL1A1 genes indicated the ability of the biomimetic coating to induce fibrocartilage phenotype in seeded cells. These results were exciting for application in tissue engineering as 3D-printed scaffolds provide a unique template for meeting structural challenges in meniscus replacement.