Biomaterials for tissue engineering and regenerative medicine: Treatment of musculoskeletal injury and disease

Musculoskeletal tissue damage is an increasing problem with a growing aging population. Biomaterials are emerging as extracellular-mimicking platforms designed to provide instructive cues to control cell behavior and ultimately, be applied as therapies to repair, improve, or maintain tissue function. Here, the focus will be on treatment of musculoskeletal disease and injury. Specifically, (a) development of tissue-engineered alternatives and identification of structure–property relationships for musculoskeletal tissue repair in vivo and (b) modification of proteins and application of natural and synthetic materials for targeted therapeutic delivery to tissue surfaces will be discussed. Efficacy of cell-laden implants for cartilage repair can be aided by both the persistence of implanted cells as well as the depth-associated cell organization of superficial and middle cells in implanted constructs. In the case of mild or early osteoarthritis, delivery of functionalized PRG4 to altered cartilage surfaces may be applied in delaying progression of the disease. Modification of biological surfaces with synthetic peptides is also addressed. Future work in the area should focus on the role of microenvironment in and the development of biomaterials for controlling cell fate.