title: Modulation of voltage-gated conductances of retinal horizontal cells by UV-excited TiO2nanoparticles.
abstract: This study examines the ability of optically-excited titanium dioxide nanoparticles to influence voltage-gated ion channels in retinal horizontal cells. Voltage clamp recordings were obtained in the presence and absence of TiO2and ultraviolet laser excitation. Significant current changes were observed in response to UV light, particularly in the -40 mV to +40 mV region where voltage-gated Na+and K+channels have the highest conductance. Cells in proximity to UV-excited TiO2exhibited a left-shift in the current-voltage relation of around 10 mV in the activation of Na+currents. These trends were not observed in control experiments where cells were excited with UV light without being exposed to TiO2. Electrostatic force microscopy confirmed that electric fields can be induced in TiO2with UV light. Simulations using the Hodgkin-Huxley model yielded results which agreed with the experimental data and showed the I-V characteristics of individual ion channels in the presence of UV-excited TiO2.
authors.affiliation: Department of Bioengineering, University of Illinois, Chicago, IL, USA. Electronic address: xmeshik@gmail.com.
authors.forename: Xenia
authors.initials: X
authors.lastname: Meshik
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois, Chicago, IL, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Choi
authors.affiliation: Biological Sciences Department, University of Illinois, Chicago, IL, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Baker
authors.affiliation: Biological Sciences Department, University of Illinois, Chicago, IL, USA; Opthamology & Visual Science Department, University of Illinois, Chicago, IL, USA.
authors.forename: R Paul
authors.initials: RP
authors.lastname: Malchow
authors.affiliation: Department of Bioengineering, University of Illinois, Chicago, IL, USA.
authors.forename: Leigha
authors.initials: L
authors.lastname: Covnot
authors.affiliation: Department of Bioengineering, University of Illinois, Chicago, IL, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Doan
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois, Chicago, IL, USA.
authors.forename: Souvik
authors.initials: S
authors.lastname: Mukherjee
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois, Chicago, IL, USA.
authors.forename: Sidra
authors.initials: S
authors.lastname: Farid
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois, Chicago, IL, USA; Department of Physics, University of Illinois, Chicago, IL, USA.
authors.forename: Mitra
authors.initials: M
authors.lastname: Dutta
authors.affiliation: Department of Bioengineering, University of Illinois, Chicago, IL, USA; Department of Electrical and Computer Engineering, University of Illinois, Chicago, IL, USA; Department of Physics, University of Illinois, Chicago, IL, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Stroscio
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000528:radiation effects; D000818:Animals; D002397:Catfishes; D002478:Cells, Cultured; D008564:Membrane Potentials; D053758:Nanoparticles / Q000737:chemistry; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D051248:Retinal Horizontal Cells / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*; D014466:Ultraviolet Rays; D061566:Voltage-Gated Sodium Channels / Q000378:metabolism*
chemical_list: D024642:Potassium Channels, Voltage-Gated; D061566:Voltage-Gated Sodium Channels; C009495:titanium dioxide; D014025:Titanium
keywords: Electrostatic force microscopy; Hodgkin–Huxley model; Retinal horizontal cell; TiO(2) nanoparticle; Voltage-gated ion channel