Biocompatible protoporphyrin IX-containing nanohybrids with potential applications in photodynamic therapy

Protoporphyrin IX was immobilized in the interlayer region of Mg-Al layered double hydroxides in order to produce biocompatible nanohybrids that could find applications in photodynamic therapy. Protoporphyrin IX and perfluoroheptanoic acid were also cointercalated to produce nanohybrids that combine the oxygen dissolving properties of perfluorocarbons with the photodynamic effect of the porphyrin. The various nanohybrids were characterized by using X-ray diffraction, Fourier transformed infrared spectroscopy, ultraviolet-visible spectroscopy and thermogravimetric analysis. In addition to the intercalation of protoporphyrin IX in the interlayer region of the layered double hydroxides, the X-ray diffraction pattern also showed that intercalation of perfluoroheptanoic acid resulted in the formation of a bilayer between the inorganic layers. Photooxidation experiments using substrates such as imidazole, 2,3-dimethyl-2-butene or linoleic acid, demonstrated the generation of singlet oxygen by these nanohybrids. (c) 2006 Elsevier B.V. All rights reserved.