Nano-Sized, Daisy-Shaped Drug Carriers Fight Cancer Cells from Within

North Carolina State researchers have developed a daisy-shaped drug carrier that, once injected into the bloodstream, sneaks inside cancer cells and releases a cocktail of drugs to destroy them from within. By ensuring anti-cancer drugs reach their target in controlled, coordinated doses, these 'nanodaisies' could cut down on the side effects of traditional chemotherapy. The nanocarriers are made from a polymer called polyethylene glycol (PEG), to which researchers attach the cancer-killing drug camptothecin (CPT). A second drug, doxorubicin, also floats in solution around the PEG. Both drugs are hydrophobic, meaning they dislike water. PEG, though, is hydrophilic - when exposed to water it stretches out to maximize contact, while the T-shaped joints that hold the CPT tug in the opposite direction and fold inward. The anti-cancer drugs thus end up tucked into a protective shell of PEG. The resulting nanocarrier is shaped like a flower - hence the name nanodaisy. Once folded, the nanodaisies are then injected into the bloodstream and absorbed by cancer cells, which are porous enough to let them in. The nanodaisies' outer shells of PEG protect their payload of drugs and keep them from prematurely leaking.