Over-Confluence of expanded bone marrow mesenchymal stem cells ameliorates their chondrogenic capacity in 3D cartilage tissue engineering

Abstract

Cartilage tissue engineering using bone marrow-derived mesenchymal stem cells (BM-MSCs) is a growing technology for the repair of joint defects. Culturing BM-MSCs to over confluence has historically been avoided due to perceived risk to cell viability, growth inhibition and differentiation potential. Here we show that a simple change in culture practice, based on mimicking the condensation phase during embryonic cartilage development, results in biochemically and histologically superior cartilage tissue engineered constructs. Whole transcriptome analysis of the condensing cells revealed a phenotype associated with early commitment to chondrogenic precursors. This simple adjustment to the common stem cell culture technique would impact the quality of all cartilage tissue engineering modalities utilising these cells.