5. Nanomaterials Applications in Cartilage Tissue Engineering

Articular cartilage is the smooth layer of soft tissue that covers our bones and allows for the painless movement of our joints. Because of joint pathologies such as arthritis, cartilage can degrade over time in some individuals, causing them to live with considerable pain and reduced mobility. The high prevalence of arthritis and the absence of a cure for osteoarthritis, its most common form, have fueled sustained efforts to develop tissue engineering and regenerative medicine strategies aimed at regenerating cartilage. Despite a number of clinical advances that elicit cartilage repair, true regeneration remains elusive. Recent years have seen an increased use of nanoscale materials in the development of therapies for joint pathologies. Nanomaterials are comparable in scale to the principal building blocks of cartilage extracellular matrix, namely collagen and proteoglycan aggregates. Similarly, nanoparticles are sufficiently small to allow diffusion through the pores of the dense cartilage extracellular matrix and cell targeting. In this chapter, the organization of cartilage’s main building blocks will be reviewed from the nano- to macroscale, and sub-micron particles that participate in cell-cell communication will be highlighted. Efforts to design scaffolds incorporating cell-instructive nanoscale features and to tailor the mechanical properties, or even engineer spatial organization, in scaffolds for cartilage repair using nanomaterials will also be discussed. Finally, key design criteria in nanoparticle synthesis to enable targeted therapeutic delivery will be examined.