title: Toward the understanding of the photodynamic activity of m-THPP encapsulated in PLGA nanoparticles: correlation between nanoparticle properties and in vivo activity.
abstract: Biodegradable polymeric nanoparticles (NP) are promising delivery systems for photosensitizers (PS). A hydrophobic PS, the meso-tetra(p-hydroxyphenyl)porphyrin (m-THPP) was encapsulated into NP made of poly(D,L-lactide-co-glycolide) using an emulsification-diffusion method, and poly(vinyl alcohol) (PVAL) as stabilizing agent during the emulsification step. Three batches of NP with mean diameters of 117, 285, and 593 nm, respectively, were prepared. NP of 117 nm exhibited the highest rate of reactive oxygen species production and the fastest m-THPP release determined by the transfer of m-THPP to serum proteins in vitro. Similarly, the 117 nm batch exhibited the highest in vivo photodynamic activity, as established in the chick embryo chorioallantoic membrane model. Our data suggest that m-THPP release before illumination is an important step for in vivo photodynamic activity especially for large NP. The NP size and the amount of residual PVAL at the NP surface were shown to control both the PS release and activity.
authors: Department of Pharmaceutics and Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland.
authors: Angelica
authors: A
authors: Vargas
authors: Norbert
authors: N
authors: Lange
authors: Tudor
authors: T
authors: Arvinte
authors: Radovan
authors: R
authors: Cerny
authors: Robert
authors: R
authors: Gurny
authors: Florence
authors: F
authors: Delie
mesh_terms: D000818:Animals; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry; D004655:Emulsions; D006016:Glycolates / Q000737:chemistry; D019344:Lactic Acid; D053758:Nanoparticles; D010316:Particle Size; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011142:Polyvinyl Alcohol / Q000737:chemistry; D011166:Porphyrins / Q000008:administration & dosage*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D006016:Glycolates; D017319:Photosensitizing Agents; D011166:Porphyrins; D017382:Reactive Oxygen Species; C481734:meso-tetra-(4-hydroxyphenyl)porphyrin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011142:Polyvinyl Alcohol