Nanoparticles

Cells are normally searching for bacterial invaders and potential tumor cells, if they recognize one, they induce an immune response. However, healthy T-cell “checkpoints” can be muted by other proteins on the cell surface and can in turn weaken immune responses. This phenomenon is often seen in tumor cells where muted T-cell checkpoint molecules are expressed. To overcome this problem without the need of radiation, nontoxic nanoparticles can be used to sensitize the immune system. New antigens can be exposed to T cells which can prime those T cells to target other tumor cells that carry them as well. In order to get past the immune system, they need to be the appropriate size because small particles are more likely to get around macrophages. Prior to inducing them into the body, they have to be coated with polyethylene glycol shell which can help them survive longer in the bloodstream.