Nanoparticles in Medicine: Nanoparticle Engineering for Macrophage Targeting and Nanoparticles that Avoid Macrophage Recognition

The use of NPs in medicine is promising, both for therapeutic and diagnostic scopes such as the delivery of drugs, and for preventive strategies, such as the vaccination, due to the possibility of exploiting the physicochemical characteristics of the particles for selective targeting. Nanomedicines delivered into the human body come into contact with the macrophage, which is the major differentiated cell of the mononuclear phagocyte system. These cells are widely distributed and strategically placed in many tissues of the body to combat microbial and other particulate invaders and perform a vast array of homeostatic functions. Given the relevance of macrophage-particle interaction for immunomodulation in medicine, this chapter will focus on the well-studied role of macrophages in the clearance of nanomedicines and synthetic particulate systems in general. Aspects of particle engineering for macrophage targeting are discussed, as well as strategies to avoid macrophage recognition of nanoparticles in clinical scenarios where this is necessary.