Enhancement of biological activities of nanostructured hydrophobic drug species.

We report a study of nanoribbons of quercetin, a phase I clinical trial anticancer drug, and their inhibitory effects on cancer cell proliferation. Novel quercetin nanoribbons have been prepared by atmospheric pressure physical vapor deposition (PVD). The nanostructures have been characterized by optical microscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy, etc. Significantly enhanced solubility in PBS solution and increased drug release rate have been observed for quercetin nanoribbons in comparison to those of quercetin powder. The observed increase of inhibitory effects of quercetin nanoribbons on 4T1 cancel cell growth is correlated with an improvement in their solubility and drug release behavior.