title: The Effect of Coatings on the Affinity of Lanthanide Nanoparticles to MKN45 and HeLa Cancer Cells and Improvement in Photodynamic Therapy Efficiency.
abstract: An improvement in photodynamic therapy (PDT) efficiency against a human gastric cancer cell line (MKN45) with 5-aminolevulinic acid (ALA) and lanthanide nanoparticles (LNPs) is described. An endogenous photosensitizer, protoporphyrin IX, biosynthesized from ALA and selectively accumulated in cancer cells, is sensitizable by the visible lights emitted from up-conversion LNPs, which can be excited by a near-infrared light. Ten kinds of surface modifications were performed on LNPs, NaYF₄(Sc/Yb/Er) and NaYF₄(Yb/Tm), in an aim to distribute these irradiation light sources near cancer cells. Among these LNPs, only the amino-functionalized LNPs showed affinity to MKN45 and HeLa cancer cells. A PDT assay with MKN45 demonstrated that amino-modified NaYF₄(Sc/Yb/Er) gave rise to a dramatically enhanced PDT effect, reaching almost perfect lethality, whereas NaYF₄(Yb/Tm)-based systems caused little improvement in PDT efficiency. The improvement of PDT effect with the amino-modified NaYF₄(Sc/Yb/Er) is promising for a practical PDT against deep cancer cells that are reachable only by near-infrared lights.
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J2-10, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. sawamura.t.ab@m.titech.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sawamura
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J2-10, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. tatsumiya2015@gmail.com.
authors.forename: Tatsumi
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J2-10, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. ishige.h.ab@m.titech.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishige
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J2-10, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. masayuki.iizuka.12@gmail.com.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Iizuka
authors.affiliation: Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachihirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. murayama@koto.kpu-m.ac.jp.
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Murayama
authors.affiliation: Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachihirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. otsuji@koto.kpu-m.ac.jp.
authors.forename: Eigo
authors.initials: E
authors.lastname: Otsuji
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J2-10, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. ohkubo.a.aa@m.titech.ac.jp.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ohkubo
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J2-10, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. sogura@bio.titech.ac.jp.
authors.forename: Shun-Ichiro
authors.initials: S
authors.lastname: Ogura
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, J2-10, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. hyuasa@bio.titech.ac.jp.
authors.forename: Hideya
authors.initials: H
authors.lastname: Yuasa
mesh_terms: D000622:Aminolevulinic Acid / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000009:adverse effects* / Q000737:chemistry; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry; D011524:Protoporphyrins / Q000737:chemistry
chemical_list: D028581:Lanthanoid Series Elements; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid
keywords: ALA; lanthanide nanoparticle; near-infrared; up-conversion luminescence