title: Effective near-infrared photodynamic therapy assisted by upconversion nanoparticles conjugated with photosensitizers.
abstract: A drug model photosensitizer-conjugated upconversion nanoparticles nanocomplex was explored for application in near-infrared photodynamic therapy. As near-infrared penetrates deeper into the tissue, the model is useful for the application of photodynamic therapy in deeper tissue. The nanocomplex that was synthesized had low polydispersity, and the upconversion nanoparticle was covalently conjugated with the photosensitizer. The robust bond could prevent the undesired premature release of photosensitizer and also enhance the singlet-oxygen generation. Singlet-oxygen generation rate from this nanocomplex was evaluated in solution. The photodynamic therapy effect was assessed with MCF-7 cells in two different methods, 3-(4,5-dimethylth-iazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead assay. The assay results showed that promising efficacy (>90%) can be achieved with a low concentration (50 μg mL(-1)) of this nanocomplex and mild dosage (7 mW cm(-2)) of near-infrared laser treatment.
authors.affiliation: Institute of Materials Research and Engineering, ASTAR, Singapore.
authors.forename: Qing Qing
authors.initials: QQ
authors.lastname: Dou
authors.affiliation: Institute of Materials Research and Engineering, ASTAR, Singapore.
authors.forename: Choon Peng
authors.initials: CP
authors.lastname: Teng
authors.affiliation: Institute of Materials Research and Engineering, ASTAR, Singapore.
authors.forename: Enyi
authors.initials: E
authors.lastname: Ye
authors.affiliation: Institute of Materials Research and Engineering, ASTAR, Singapore ; Department of Materials Science and Engineering, National University of Singapore, Singapore ; Singapore Eye Research Institute, Singapore.
authors.forename: Xian Jun
authors.initials: XJ
authors.lastname: Loh
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007259:Infrared Rays; D061986:MCF-7 Cells; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D017319:Photosensitizing Agents
keywords: MTT assay; live/dead assay; nanocomplex; singlet-oxygen generation rate