title: High-resolution imaging of living mammalian cells bound by nanobeads-connected antibodies in a medium using scanning electron-assisted dielectric microscopy.
abstract: Nanometre-scale-resolution imaging technologies for liquid-phase specimens are indispensable tools in various scientific fields. In biology, observing untreated living cells in a medium is essential for analysing cellular functions. However, nanoparticles that bind living cells in a medium are hard to detect directly using traditional optical or electron microscopy. Therefore, we previously developed a novel scanning electron-assisted dielectric microscope (SE-ADM) capable of nanoscale observations. This method enables observation of intact cells in aqueous conditions. Here, we use this SE-ADM system to clearly observe antibody-binding nanobeads in liquid-phase. We also report the successful direct detection of streptavidin-conjugated nanobeads binding to untreated cells in a medium via a biotin-conjugated anti-CD44 antibody. Our system is capable of obtaining clear images of cellular organelles and beads on the cells at the same time. The direct observation of living cells with nanoparticles in a medium allowed by our system may contribute the development of carriers for drug delivery systems (DDS).
authors.affiliation: Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Okada
authors.affiliation: Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ogura
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry* / Q000276:immunology; D001710:Biotin / Q000737:chemistry; D045744:Cell Line, Tumor; D058266:Dielectric Spectroscopy / Q000295:instrumentation / Q000379:methods*; D018960:Hyaluronan Receptors / Q000276:immunology / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D017655:Silicon Compounds / Q000737:chemistry; D019809:Streptavidin / Q000737:chemistry; D014414:Tungsten / Q000737:chemistry
chemical_list: D000906:Antibodies; C476399:Cd44 protein, mouse; D018960:Hyaluronan Receptors; D017655:Silicon Compounds; D001710:Biotin; D019809:Streptavidin; C032734:silicon nitride; D014414:Tungsten