A new sol-gel silica nanovehicle preparation for photodynamic therapy in vitro.

We report a facile silica nanovehicle preparation procedure for hydrophobic drug delivery, which is carried out in water without adding any surfactant and additional catalyst. This strategy includes hydrophobic drug nanopaticle preparation by reprecipitation method and in situ hydrolyzation and polymerization to encapsulate this naoparticle using only N-(beta-amimoethyl)-gamma-aminopropyltriethoxysilane (AETPS). To demonstrate this technique hypocrellin A (HA), a hydrophobic photosensitizing anticancer drug, is embedded into silica nanovehicle using this simple method. The resulting HA encapsulated nanovehicles (HANV) are monodisperse and stable in aqueous solution. Comparative studies with free HA and entrapped HA have demonstrated that the encapsulation effect on the embedded photosensitizer nanoparticle significantly enhances the efficacy of singlet oxygen generation and, thereby, the in vitro photodynamic efficacy. Copyright 2009 Elsevier B.V. All rights reserved.