Encapsulation of hydrophobic anticancer drug in nano-scale porous ceramic materials for photodynamic therapy

Abstract

A hydrophilic nano-scale porous ceramic material, silica nano-carrier, was prepared using microemulsion method to deliver hypocrellin A (HA), a hydrophobic photosensitive anti-cancer drug, to cancer cells in vitro. The result hypocrellin A encapsulated silica nano-carrier delivery systems (HA-SNDS) are spherical, highly monodispersed, stable in aqueous system and own high drug encapsulation ability. Irradiation of the HA-SNDS with light of suitable wavelength results in efficient generation of singlet oxygen; further more the photo-stability of HA-SNDS is superior to free HA. In aqueous medium, the fluorescence intensity of the entrapped drug is stronger than the free drug, permitting use of fluorescence mediated bioimaging studies. In addition, HA-SNDS was stable at a wide range of pH. In vitro studies have demonstrated the active uptake of HA-SNDS into the cytosol of tumor cells. Comparative studies with free HA and HA-SNDS have demonstrated that the in vitro PDT efficacy of encapsulated HA is obvious superior to free HA. All these properties of HA-SNDS could make it a promising candidate for photodynamic therapy.