Cell-Homing Strategies for in Situ Articular Cartilage Regeneration

Injuries to articular cartilage (AC) can lead to cartilage degeneration without timely and proper treatments and ultimately results in osteoarthritis. Regenerative medicine and tissue engineering techniques are emerging as promising approaches for AC regeneration and repair. Typically, AC regenerative medicine and tissue engineering can be divided into two categories, cell-based tissue engineering and cell-homing tissue engineering techniques, based on the involvement of seed cells. Although numerous cell-based techniques can regenerate and repair cartilage lesions to some extent, existing strategies are still restricted by limited cell sources, excessive costs, risks of disease transmission and complex manufacturing practices. However, cell-homing tissue engineering strategies avoid these drawbacks and offer great promise for in situ AC regeneration. These strategies rely on the recruitment of endogenous stem/progenitor cells, host tissue stimulation, and functional responses and thus can provide new insights into in situ cartilage regeneration. This review provides a brief overview of the status of cell-homing tissue engineering strategies; the subpopulations, distribution and migration routes of native joint-resident stem/progenitor cells for regenerating cartilage; chemoattractants that induce enhanced endogenous cell homing; and drug delivery systems and biofunctionalized scaffolds that are indispensable for facilitating in situ AC regeneration and repair.