title: Oxidized silicon nanoparticles for radiosensitization of cancer and tissue cells.
abstract: The applicability of ultrasmall uncapped and aminosilanized oxidized silicon nanoparticles (SiNPs and NH2-SiNPs) as radiosensitizer was studied by internalizing these nanoparticles into human breast cancer (MCF-7) and mouse fibroblast cells (3T3) that were exposed to X-rays at a single dose of 3 Gy. While SiNPs did not increase the production of reactive oxygen species (ROS) in X-ray treated cells, the NH2-SiNPs significantly enhanced the ROS formation. This is due to the amino functionality as providing positive surface charges in aqueous environment. The NH2-SiNPs were observed to penetrate into the mitochondrial membrane, wherein these nanoparticles provoked oxidative stress. The NH2-SiNPs induced mitochondrial ROS production was confirmed by the determination of an increased malondialdehyde level as representing a gauge for the extent of membrane lipid peroxidation. X-ray exposure of NH2-SiNPs incubated MCF-7 and 3T3 cells increased the ROS concentration for 180%, and 120%, respectively. Complementary cytotoxicity studies demonstrate that these silicon nanoparticles are more cytotoxic for MCF-7 than for 3T3 cells.
authors.affiliation: Department Chemistry and Pharmacy, Physical Chemistry I and ICMM, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstr. 3, D-91058 Erlangen, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Klein
authors.forename: Maria L
authors.initials: ML
authors.lastname: Dell'Arciprete
authors.forename: Marc
authors.initials: M
authors.lastname: Wegmann
authors.forename: Luitpold V R
authors.initials: LV
authors.lastname: Distel
authors.forename: Winfried
authors.initials: W
authors.lastname: Neuhuber
authors.forename: Mónica C
authors.initials: MC
authors.lastname: Gonzalez
authors.forename: Carola
authors.initials: C
authors.lastname: Kryschi
mesh_terms: D016475:3T3 Cells; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002470:Cell Survival / Q000187:drug effects; D003600:Cytosol / Q000737:chemistry; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D006801:Humans; D061986:MCF-7 Cells; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000737:chemistry / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000737:chemistry / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry / Q000627:therapeutic use*; D036103:Nanotechnology / Q000379:methods; D009369:Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010316:Particle Size; D011838:Radiation-Sensitizing Agents / Q000737:chemistry / Q000627:therapeutic use*; D017382:Reactive Oxygen Species / Q000737:chemistry; D012825:Silicon / Q000737:chemistry / Q000627:therapeutic use*; D014965:X-Rays
chemical_list: D000970:Antineoplastic Agents; D011838:Radiation-Sensitizing Agents; D017382:Reactive Oxygen Species; D012825:Silicon