Hypersensitivity and nanoparticles: update and research trends

Nanotechnology holds a great promise for a wide range of medical-intent applications (diagnostic, treatment and prophylaxis of various diseases). Their advantages are due to their size, versatility and potential for multiple simultaneous applications. However, concerns have been formulated by scientific world due to insufficient data on toxicity of nanomaterials. One area of interest is represented by the interactions between nanoparticles and the components of the immune system. We review herein reported data on hypersensitivity reactions. The role exerted by nanoparticles in both immunostimulation and immunosuppression in allergen-driven mechanisms was studied, as well as future trends in worldwide research.