Going with the flow

Manufactured nanoparticles are a new class of substance, and can be made from almost any solid material. typical examples include silver particles used as an antibacterial and antifungal agent in water bottles, zinc oxide used to block UVA and UVB sun rays in sunscreen, and the various materials used as pigments in paints and cosmetics. the variety in their chemical compositions, shapes and surface properties means that they can interact with the body in very different ways, and their small size allows them to cross barriers in the body that hold back larger materials.