title: In Vivo Near-Infrared Photodynamic Therapy Based on Targeted Upconversion Nanoparticles.
abstract: Upconversion nanoparticles have shown to be a promising prospect for biological detection and photodynamic therapy (PDT). The focus of this study was to develop an upconversion nanoparticle modified with a targeting peptide and photosensitizer for near-infrared photodynamic therapy. To produce a tumor-targeting nanophotosensitizer with near-infrared excitation, NaYF4:Yb/Er upconversion nanoparticles were first wrapped with O-carboxymethyl chitosan to develop an upconversion rianoplatform and then chemically conjugated with the photosensitizer pyropheophorbide-a (Ppa) and RGD peptide c(RGDyK). The nanoparticle exhibited low dark toxicity and high biocompatibility. When injected into the tail vein of tumor-bearing U87-MG mice, UCNP-Ppa-RGD revealed an enhanced tumor-specific biodistribution and successful therapeutic effect following near-infrared laser irradiation. It possessed a significantly deeper therapeutic depth compared with conventional visible light triggered PDT using Ppa. The results suggest that the nanoplatform has advantages in the spectral application, and the constructed tumor-specific nanoparticle shows high clinical potential to serve not only as a photodynamic imaging reagent but also as a therapeutic agent for the treatment of large or deeply seated tumors.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Zhou
authors.forename: Yanchun
authors.initials: Y
authors.lastname: Wei
authors.forename: Qun
authors.initials: Q
authors.lastname: Chen
authors.forename: Da
authors.initials: D
authors.lastname: Xing
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D048271:Chitosan / Q000031:analogs & derivatives / Q000737:chemistry; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods*; D005459:Fluorides / Q000737:chemistry; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000493:pharmacokinetics; D019265:Spectroscopy, Near-Infrared; D014018:Tissue Distribution; D015019:Yttrium / Q000737:chemistry
chemical_list: C504164:O-carboxymethylchitosan; D017319:Photosensitizing Agents; C525362:sodium yttriumtetrafluoride; D002734:Chlorophyll; C040298:pyropheophorbide a; D015019:Yttrium; D048271:Chitosan; D005459:Fluorides