title: UV-emitting upconversion-based TiO2 photosensitizing nanoplatform: near-infrared light mediated in vivo photodynamic therapy via mitochondria-involved apoptosis pathway.
abstract: Photodynamic therapy (PDT) is a promising antitumor treatment that is based on the photosensitizers that inhibit cancer cells by yielding reactive oxygen species (ROS) after irradiation of light with specific wavelengths. As a potential photosensitizer, titanium dioxide (TiO2) exhibits minimal dark cytotoxicity and excellent ultraviolet (UV) light triggered cytotoxicity, but is challenged by the limited tissue penetration of UV light. Herein, a novel near-infrared (NIR) light activated photosensitizer for PDT based on TiO2-coated upconversion nanoparticle (UCNP) core/shell nanocomposites (UCNPs@TiO2 NCs) is designed. NaYF4:Yb(3+),Tm(3+)@NaGdF4:Yb(3+) core/shell UCNPs can efficiently convert NIR light to UV emission that matches well with the absorption of TiO2 shells. The UCNPs@TiO2 NCs endocytosed by cancer cells are able to generate intracellular ROS under NIR irradiation, decreasing the mitochondrial membrane potential to release cytochrome c into the cytosol and then activating caspase 3 to induce cancer cell apoptosis. NIR light triggered PDT of tumor-bearing mice with UCNPs@TiO2 as photosensitizers can suppress tumor growth efficiently due to the better tissue penetration than UV irradiation. On the basis of the evidence of in vitro and in vivo results, UCNPs@TiO2 NCs could serve as an effective photosensitizer for NIR light mediated PDT in antitumor therapy.
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Zhiyao
authors.initials: Z
authors.lastname: Hou
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Yuanxin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.|‡University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Kerong
authors.initials: K
authors.lastname: Deng
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.|‡University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Yinyin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Xuejiao
authors.initials: X
authors.lastname: Li
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.|‡University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Xiaoran
authors.initials: X
authors.lastname: Deng
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Ziyong
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Hongzhou
authors.initials: H
authors.lastname: Lian
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Chunxia
authors.initials: C
authors.lastname: Li
authors.affiliation: †State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lin
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D007259:Infrared Rays; D051379:Mice; D008819:Mice, Nude; D008928:Mitochondria / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D050997:Nanomedicine; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium
keywords: NIR light mediated; core/shell structure; mitochondria-involved apoptosis; photodynamic therapy; titanium dioxide; upconversion nanoparticles