Scaffold-Free Tissue Engineered Construct (TEC) Derived from Synovial Mesenchymal Stem Cells: Characterization and Demonstration of Efficacy to Cartilage Repair in a Large Animal Model

Abstract

This chapter describes in vitro generation of a scaffold-free mesenchymal stem cell (MSC)-based tissue-engineered construct (TEC) to facilitate cartilage repair and regeneration. Synovial MSCs were cultured in monolayer at high density and were subsequently detached from the substratum. The cell/matrix complex spontaneously contracted to develop a basic TEC. Immunohistochemical analysis showed that the TEC was rich in collagen I and III, fibronectin, and vitronectin. The TEC exhibited stable adhesion to the surface of a porcine cartilage matrix in an explant culture system. The TEC cultured in chondrogenic media exhibited elevated expression of glycosaminoglycan and chondrogenic marker genes. Implantation of a TEC into chondral defects initiated repair with a chondrogenic-like tissue, as well as secure biological integration to the adjacent cartilage. Histologically, the repair tissue stained positively with Safranin O and for collagen II. Biomechanical evaluation revealed that repair tissue exhibited mechanical properties similar to those of normal porcine cartilage in static compression and friction tests. The TEC technology could be a unique and promising method for stem-cell based cartilage repair.