title: Calcium phosphate nanoparticles as efficient carriers for photodynamic therapy against cells and bacteria.
abstract: Calcium phosphate nanoparticles were surface-functionalized with different polymers, and photosensitizers were incorporated into this layer. The charge was adjusted by choosing the appropriate polymer. Methylene blue and 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (mTHPP) were used as photosensitizers. The particles showed a good performance with HIG-82 synoviocytes. For J774A.1 macrophages, they were toxic also in the dark, probably due to a lethal uptake of calcium. For HT29 epithelial cells, a moderate activity was observed. A good photoxicity was observed against the bacterial strain Staphylococcus aureus (Gram-positive), both with positively and negatively charged nanoparticles loaded with mTHPP. Against Pseudomonas aeruginosa (Gram-negative), good photoxicity was observed only with positively charged nanoparticles loaded with mTHPP. At higher concentrations, methylene blue-loaded nanoparticles were active against S. aureus. Thus, it is possible to prepare a water-dispersable system of dye-loaded calcium phosphate nanoparticles, but the efficiency depends on a number of parameters, e.g. particle charge, kind of polymer, and cell culture medium (e.g. the presence of proteins).
authors.affiliation: Inorganic Chemistry and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Universitaetsstr. 5-7, D-45117 Essen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schwiertz
authors.forename: A
authors.initials: A
authors.lastname: Wiehe
authors.forename: S
authors.initials: S
authors.lastname: Gräfe
authors.forename: B
authors.initials: B
authors.lastname: Gitter
authors.forename: M
authors.initials: M
authors.lastname: Epple
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D002130:Calcium Phosphates / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D004337:Drug Carriers / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008751:Methylene Blue / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology; D011166:Porphyrins / Q000737:chemistry / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D011817:Rabbits; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D004337:Drug Carriers; D017319:Photosensitizing Agents; D011166:Porphyrins; C437342:tetra(3-hydroxyphenyl)porphine; C020243:calcium phosphate; D008751:Methylene Blue