nanoparticles

Definition of nanoparticle
National Cancer Institute

nanoparticle

(NA-noh-PAR-tih-kul)
A particle of that is smaller than 100 nanometers (one-billionth of a meter). In medicine, nanoparticles can be used to carry antibodies, drugs, imaging agents, or other substances to certain parts of the body. Nanoparticles are being studied in the detection, diagnosis, and treatment of cancer.

Source: NCI Dictionary of Cancer Terms