The immune system is the responsible for body integrity and the prevention of external invasion. In principle, the immune system has not been evolutionarily trained to respond against inorganic engineered nanoparticles (NPs). However, how it will react against them will determine developments on the use of NPs as medical devices and their toxicological impact on human and environmental health. Initial observations show a broad range of results as a function of size, shape, concentration and surface state of NPs, and a variety of immune responses from absent to acute inflammation. In particular for the case of NP, the composition of the material, which strongly influences its physical properties, appears not to be the main determining factor for their behavior in biological environments as compared to surface state or size.
Keywords: Nanoparticles, nanomaterials, surface modification, immune system, macrophages, endocytosis, inflammation, biodegradation