Macrophages as delivery vehicles for anticancer agents

The delivery of anticancer agents via passive approaches such as the enhanced permeability and retention effect is unlikely to achieve sufficient concentrations throughout the tumor volume for effective treatment. Cell-based delivery approaches using tumor tropic cells have the potential to overcome the limitations of passive approaches. Specifically, this review focuses on the use of monocytes/macrophages for the delivery of a variety of anticancer agents, including nanoparticles, chemotherapeutics and gene constructs. The efficacy of this delivery approach, both as monotherapy and in combination with light-based phototherapy modalities, has been demonstrated in numerous in vitro and animal studies, however, its clinical potential remains to be determined.