Coupled cellular therapy and magnetic targeting for airway regeneration.

Airway diseases including COPD (chronic obstructive pulmonary disease), cystic fibrosis and lung cancer are leading causes of worldwide morbidity and mortality, with annual healthcare costs of billions of pounds. True regeneration of damaged airways offers the possibility of restoring lung function and protecting against airway transformation. Recently, advances in tissue engineering have allowed the development of cadaveric and biosynthetic airway grafts. Although these have produced encouraging results, the ability to achieve long-term functional airway regeneration remains a major challenge. To promote regeneration, exogenously delivered stem and progenitor cells are being trialled as cellular therapies. Unfortunately, current evidence suggests that only small numbers of exogenously delivered stem cells engraft within lungs, thereby limiting their utility for airway repair. In other organ systems, magnetic targeting has shown promise for improving long-term robust cell engraftment. This technique involves in vitro cell expansion, magnetic actuation and magnetically guided cell engraftment to sites of tissue damage. In the present paper, we discuss the utility of coupling stem cell-mediated cellular therapy with magnetic targeting for improving airway regeneration.