The potential medical applications of nanotechnology are by the use of human-engineered materials/devices which can interact with biological processes and perform particular medical tasks such as destroying cancer cells, cleaning out clogged arteries or to construct needed proteins or mimicking anti-bodies.

While rapid advances are being made, significant roadblocks must be surmounted before nanotechnology can be applied in a clinical setting. For example, most of the nanomaterials used in high contrast imaging (such as quantum dots) are toxic and cannot be applied in large quantities to the body. Injectable nanovectors (such as nanoparticles and nanoshells) pose a tremendous risk if left in the Body in excess.

If treated for a long periods of time, nanoparticles may aggregate, potentially blocking arteries and veins or even blocking the kidneys, and thereby creating a host of new problems. Hence they have to be either completely destroyed or made biodegradable in vivo. Another problem is that nanomedicines may also trigger sensitization reactions and hence they need counter measures to suppress such reactions. Eventhough there are several successful methods available, these techniques will have to be combined to improve targeting efficacy, overcome biological barriers and cure the diseases.