Ultrasmall inorganic nanoparticles: State-of-the-art and perspectives for biomedical applications

Ultrasmall nanoparticles possess unique physicochemical and pharmacokinetic properties compared to classical, larger-sized nanomaterials. This review summarizes comprehensively the relevant literature regarding these nanosized objects including their synthesis and characterization, toxicity, biodistribution and clearance as well as targeting and interaction with proteins and cells. Finally, potential applications of ultrasmall nanoparticles in the emerging field of nanomedicine are discussed.102