Flower-like curcumin-loaded folic acid-conjugated ZnO-MPA- βcyclodextrin nanostructures enhanced anticancer activity and cellular uptake of curcumin in breast cancer cells.

Non-spherical structures are beneficial to advance drug delivery effectiveness compared with common spherical ones, due to increased drug loading capability, improved bonding to a vascular wall, enhanced cellular uptake efficacy and prolonged circulation times. In this study, flower-like Zinc oxide-βcyclodextrin (βCD) nanostructures functionalized by 3-mercaptopropionic acid (MPA) as a non-spherical delivery system was successfully synthesized for aqueous delivery of curcumin (CUR) to enhance its targeting, bioavailability, and release profile. Terminal carboxyl functional groups were used for the conjugation of folic acid (FA) with the aim of active targeting to folate overexpressing breast cancer cells. The in vitro experimental study and mathematical modeling of CUR release revealed a sustained release with Fickian diffusion as the major release mechanism. MTT, colony formation and Annexin-V FITC/PI assays showed the superior anticancer effect of the system compared to free CUR against breast cancer cell line MDA-MB-231 by promoting the apoptotic respond with no cytotoxic effect on HEK293 normal cells. The efficacy of targeting strategy with FA moieties was demonstrated using the augmented cellular uptake of the FA-conjugated system on overexpressed folate receptor alpha (FRα) cells (MDA-MB-468 breast cancer cell line). Furthermore, loading of CUR to the delivery systems significantly lowered the MIC values (2.5 to 5-fold) against S. aureus and E. coli the infections of which are serious problems in cancer patients. According to the results of this study, the system can serve as a promising non-spherical delivery vehicle for enhancing bioavailability and targeting of hydrophobic anticancer agents in the future.