title: Detecting HER2 on cancer cells by TiO2 spheres Mie scattering.
abstract: This work is the first to describe a bioimaging method that uses highly uniformly sized TiO(2) submicrometer and micrometer spheres based on Mie scattering. Transmembrane proteins (HER2) located on the surface of cancer cells were detected by bonded antibody-linked TiO(2) spheres using optic microscopy and UV-vis spectroscopy. A particular HER2 bond on cancer cells, which has a weaker binding affinity than the biotin/avidin interaction, can be identified between TiO(2) spheres that are linked to anti-HER2 antibodies and those that are linked to nonspecific mouse IgG antibodies by observing the cells under an optical microscope or by measuring absorbance from a UV-vis spectrum. The TiO(2) spheres used in this work was prepared by reacting TTIP with carboxylic acid, as described elsewhere and the uniformity of the TiO(2) sphere was further improved by adjusting the amount of water used. The water content was inversely related to particle size and the size distribution: as more water was used, smaller spheres with a narrower size distribution were obtained. The most uniform sphere obtained had a diameter of about 1 microm with a size variation of 3%.
authors: Department of Materials Science and Engineering, Center for Nanotechnology, Materials Science and Microsystems, National Tsing Hua University, Hsinchu, Taiwan.
authors: Min-Chiao
authors: MC
authors: Tsai
authors: Tsung-Lin
authors: TL
authors: Tsai
authors: Dar-Bin
authors: DB
authors: Shieh
authors: Hsin-Tien
authors: HT
authors: Chiu
authors: Chi-Young
authors: CY
authors: Lee
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000276:immunology; D051379:Mice; D008853:Microscopy / Q000379:methods*; D009374:Neoplasms, Experimental / Q000737:chemistry*; D044367:Phase Transition; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D012542:Scattering, Radiation; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D014025:Titanium / Q000737:chemistry*; D014407:Tumor Cells, Cultured
chemical_list: D055910:Antibodies, Immobilized; D018719:Erb-b2 Receptor Tyrosine Kinases; D014025:Titanium; C009495:titanium dioxide; C524056:Erbb2 protein, mouse