title: The embedding of meta-tetra(hydroxyphenyl)-chlorin into silica nanoparticle platforms for photodynamic therapy and their singlet oxygen production and pH-dependent optical properties.
abstract: This study relates to nanoparticle (NP) platforms that attach to tumor cells externally and only deliver singlet oxygen for photodynamic therapy (PDT) while conserving the embedded photosensitizers (PS). As a model, we demonstrate the successful embedding of the PS meta-tetra(hydroxyphenyl)-chlorin (m-THPC) in NP that are based on a sol-gel silica matrix and also show its positive effect on the singlet oxygen production. The embedding of m-THPC inside silica NP is accomplished by a modified Stöber sol-gel process, in which (3-aminopropyl)-triethoxysilane is introduced during the reaction. Singlet oxygen delivery by the targetable photodynamic NP exceeds that from free PS molecules. In the physiological pH range, there is no significant pH-induced decrease in the fluorescence of m-THPC embedded in silica NP, which might otherwise affect the efficiency of PDT.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Yan
authors.forename: Raoul
authors.initials: R
authors.lastname: Kopelman
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis; D006863:Hydrogen-Ion Concentration; D008652:Mesoporphyrins / Q000138:chemical synthesis*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000138:chemical synthesis*; D012822:Silicon Dioxide; D026082:Singlet Oxygen; D013057:Spectrum Analysis
chemical_list: D000970:Antineoplastic Agents; D008652:Mesoporphyrins; D017319:Photosensitizing Agents; D026082:Singlet Oxygen; D012822:Silicon Dioxide; C072269:temoporfin