Nanoechnology can help to get therapeutic drugs through cell walls, but can it help researchers find the right cells to target? Targeted drug delivery, involves the delivery of drugs directly to diseased cells within the body by matching antibodies to certain proteins. Researchers are trying to identify which antibodies can be attached to drug-carrying nanoparticles so that they attach to a diseased cell.

Nanoparticles have been functionalized in this way by various researchers and companies to target different types of cancers. By using therapeutic drug-carrying nanoparticles, chemotherapy drugs can be delivered directly into cancer cells. This method should stop or significantly reduce the damage that less targeted chemotherapy drugs cause to healthy cells.

Another use of functionalized nanoparticles for targeted drug delivery may help researchers tackle arteriosclerosis caused by plaque building up inside arteries. The portion of plaque most likely to flake off and cause a blockage downstream is on the edge of the plaque buildup, where the plaque meets the artery wall.

Researchers have determined how to target nanoparticles to these critical regions of plaque buildup so that therapeutic drug molecules are delivered where they can be most effective.

One problem with having nanoparticles searching out diseased cells floating through the bloodstream of a patient is that white blood cells in the immune system attack foreign materials in the bloodstream. To solve this, researchers attach molecules called polyethylene glycol (PEG), which hide the nanoparticles from the immune system. The PEG allows the nanoparticles to flow through the bloodstream without being detected.