title: Core-shell upconversion nanoparticle - semiconductor heterostructures for photodynamic therapy.
abstract: Core-shell nanoparticles (CSNPs) with diverse chemical compositions have been attracting greater attention in recent years. However, it has been a challenge to develop CSNPs with different crystal structures due to the lattice mismatch of the nanocrystals. Here we report a rational design of core-shell heterostructure consisting of NaYF4:Yb,Tm upconversion nanoparticle (UCN) as the core and ZnO semiconductor as the shell for potential application in photodynamic therapy (PDT). The core-shell architecture (confirmed by TEM and STEM) enables for improving the loading efficiency of photosensitizer (ZnO) as the semiconductor is directly coated on the UCN core. Importantly, UCN acts as a transducer to sensitize ZnO and trigger the generation of cytotoxic reactive oxygen species (ROS) to induce cancer cell death. We also present a firefly luciferase (FLuc) reporter gene based molecular biosensor (ARE-FLuc) to measure the antioxidant signaling response activated in cells during the release of ROS in response to the exposure of CSNPs under 980 nm NIR light. The breast cancer cells (MDA-MB-231 and 4T1) exposed to CSNPs showed significant release of ROS as measured by aminophenyl fluorescein (APF) and ARE-FLuc luciferase assays, and ~45% cancer cell death as measured by MTT assay, when illuminated with 980 nm NIR light.
authors: Institute of Materials Research and Engineering (IMRE), A * STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602.
authors: Qing Qing
authors: QQ
authors: Dou
authors: Molecular Imaging Program at Stanford, Bio-X Program, Stanford University School of Medicine, Palo Alto, California 94304, USA.
authors: Adith
authors: A
authors: Rengaramchandran
authors: 1] Institute of Materials Research and Engineering (IMRE), A * STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 [2] Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575.
authors: Subramanian Tamil
authors: ST
authors: Selvan
authors: Molecular Imaging Program at Stanford, Bio-X Program, Stanford University School of Medicine, Palo Alto, California 94304, USA.
authors: Ramasamy
authors: R
authors: Paulmurugan
authors: Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575.
authors: Yong
authors: Y
authors: Zhang
mesh_terms: D002460:Cell Line; D002470:Cell Survival; D015870:Gene Expression; D023061:Gene Order; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D010778:Photochemotherapy / Q000379:methods; D045663:Quantum Dots / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D017382:Reactive Oxygen Species / Q000378:metabolism; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D017382:Reactive Oxygen Species; D012996:Solutions; D015034:Zinc Oxide
references: Small. 2009 Oct;5(20):2285-90
references: 19598161
references: J Am Chem Soc. 2013 Jun 12;135(23):8571-7
references: 23687972
references: ACS Nano. 2013 Jan 22;7(1):676-88
references: 23252747
references: Future Oncol. 2006 Feb;2(1):53-71
references: 16556073
references: Nat Cell Biol. 2005 Nov;7(11):1118-23
references: 16227967
references: Nat Rev Mol Cell Biol. 2007 Oct;8(10):813-24
references: 17848967
references: Nat Nanotechnol. 2013 Oct;8(10):729-34
references: 23995455
references: Nat Chem. 2010 Jul;2(7):581-7
references: 20571578
references: Science. 2010 Mar 26;327(5973):1634-8
references: 20339071
references: Photochem Photobiol. 2009 Sep-Oct;85(5):1177-81
references: 19508643
references: Nat Rev Cancer. 2003 May;3(5):380-7
references: 12724736
references: Genes Dev. 1999 Jan 1;13(1):76-86
references: 9887101
references: Nat Med. 2012 Oct;18(10):1580-5
references: 22983397
references: Chem Commun (Camb). 2010 Mar 14;46(10):1766-8
references: 20177643
references: J Chem Phys. 2004 Jun 1;120(21):10037-45
references: 15268025
references: J Am Chem Soc. 2013 Jul 3;135(26):9659-64
references: 23742128
references: Proc Natl Acad Sci U S A. 2007 Jan 2;104(1):66-71
references: 17190801
references: Environ Sci Technol. 2006 Apr 15;40(8):2838-43
references: 16683632
references: Trends Biotechnol. 2008 Nov;26(11):612-21
references: 18804298
references: Nat Rev Mol Cell Biol. 2007 Sep;8(9):722-8
references: 17700625
references: Langmuir. 2011 Nov 1;27(21):13236-41
references: 21919438
references: FASEB J. 1996 May;10(7):709-20
references: 8635688
references: Braz J Med Biol Res. 2005 Jul;38(7):995-1014
references: 16007271
references: J Biol Chem. 2005 Apr 29;280(17):16891-900
references: 15734732
references: ACS Nano. 2012 May 22;6(5):4054-62
references: 22463487
references: J Biomed Nanotechnol. 2011 Feb;7(1):95-7
references: 21485821
references: J Biomed Opt. 2001 Jul;6(3):287-91
references: 11516318
references: Proc Natl Acad Sci U S A. 2012 Sep 18;109(38):15115-20
references: 22949699