Halloysite clay nanotubes as carriers for curcumin delivery

Halloysite is a nanostructured clay mineral with hollow tubular structure, which has recently found an important role as delivery sistem for drugs or other active molecules. One of these is curcumin, main constituent in the rhizome of the plant Curcuma Longa, with a series of useful pharmacological activities, hindered by its poor solubility in water and bioavalaibility. In this study, Halloysite Clay Nanotubes (HNTs) were characterized in terms of both structure and biocompatibily and they were used for curcumin delivery to cancer cells. The performed MTT assay showed that HNTs have a high biocompatibility, also when coated with polymers, while curcumin is highly toxic for cancer cells. The release kinetics of curcumin from HNTs was investigated by the dialysis bag method, showing a slow and constant release of the drug, which can be further controlled by adding layers of polymers to the external surface of the tubes. The Trypan Blue assay showed a cytotoxic effect of loaded HNTs, proportional to the concentration of tubes and the incubation time.