Macrophage-mediated cancer drug delivery

Cell-mediated drug delivery systems have attracted significant research interest in the past years owing to their superior properties such as excellent biocompatibility, potential long circulation, intrinsic homing properties, and ability to permeate biological barriers. Macrophages, as one of the major phagocytes of the innate immune system, represent a promising target for cancer drug delivery because, on the one hand, they play critical roles in the tumor microenvironment in various stages of tumor progression and, on the other hand, they can be harnessed as Trojan horses for enhanced drug delivery. This article provides a mini-review of the different aspects of macrophages for cancer therapy including tumor-associated macrophages (TAMs) in the tumor microenvironment, novel cancer treatment targeting TAMs, and nanoparticle-loaded macrophages as tumor-infiltrating drug carriers.