Chapter 54 - Mesenchymal Stem Cells in Musculoskeletal Tissue Engineering

Abstract

Mesenchymal stem cells (MSCs) found in adult tissues function as progenitor cells that can proliferate and differentiate into various mesenchymal cell lineages, including those that are the building blocks of musculoskeletal system. Due to their ease of isolation, their extensive proliferation capacity and their multilineage differentiation potential, MSCs are considered the cell type of choice for musculoskeletal tissue engineering. This chapter will first survey current knowledge of MSC biology that serves as the scientific foundation to guide approaches in musculoskeletal tissue engineering. Relevant information regarding MSC tissue origin, isolation and in vitro culture, and factors controlling their proliferation as well as multipotential differentiation will be reviewed. In addition, recent recognition of the immunosuppressive and immuno-modulatory properties of MSCs will be discussed, as this is critical for the safe usage of MSCs in allogeneic transplantation, which is often the case with tissue-engineered products. In the second part, we survey the use of MSCs in the engineering of musculoskeletal tissues, including cartilage, bone, tendon and osteochondral constructs. Focusing on cartilage and the factors that regulate the ultimate outcome of tissue-engineered cartilage replacement, we will review the biological processes that regulate MSC chondrogenesis, and how they may be co-opted to promote cartilage tissue engineering in the context of the three critical elements of successful tissue engineering-cells, scaffolds, and environment. While MSCs hold great potential for musculoskeletal systems, there are challenges, from a better understanding of their biology, to the application of such information to optimize tissue neogenesis, and the development of functional scaffolds for tissue engineering.