Advances in Living Cell-Mediated Nanodrug Delivery Systems: Construction Strategies, Applications and Challenges.

Nanodrug delivery systems have shown great promise against tumors, inflammatory diseases and central nervous system disorders. However, several limitations still exist before further clinical application. The unsatisfactory circulation time in vivo, rapid clearance by the mononuclear phagocyte system, insufficient tissue penetration and low targeting efficiency all hinder the clinical translation of nanomedicines. Cells are the fundamental functional units of the body and their intrinsic biological properties make them promising drug delivery vehicles for targeted therapy. Conjugating cells with nanomedicines combines the carrier functions of living cells with the therapeutic effects of nanodrugs, offering an effective strategy to improve targeted drug delivery. Compared with the existing literature, this review specifically summarizes the biological properties and major applications of six types of living cell carriers. The recent strategies for constructing cell-nanomedicine conjugates are also discussed. Finally, we highlight the current challenges for clinical translation and discuss future directions for the development of cell-nanomedicine delivery systems.