Characterization by Electron Spin Resonance Spectroscopy of Reactive Oxygen Species Generated by Titanium Dioxide and Hydrogen Peroxide

Abstract

The influence of reactive oxygen species (ROS) on the surface modification of titanium implants and osseointegration is unclear. The aim of this study was to evaluate the ability of titanium dioxide (TiO2) to generate ROS in the presence of H2O2 and to determine whether any ROS thus generated play a role in osseointegration, as measured by electron spin resonance (ESR) spin-trapping with 5,5-dimethyl-1-pyrolline-N-oxide (DMPO). We demonstrate that TiO2 together with H2O2 generated hydroxyl radicals (HO*), as shown by a time-dependent increase in the spin concentration of the ESR signal for the DMPO-OH spin adduct, indicating HO* generation. Interestingly, irradiated TiO2 with H2O2 generated the superoxide (O2*-), as shown by an increase in the spin concentration of the signal for the DMPO-OOH spin adduct, indicating O2*- generation during the period of irradiation (0-5 min). These results suggest that ROS generated from the TiO2 layer may be involved in creating appropriate conditions for the osseointegration of dental implants into alveolar bone tissues.

Role of physical and chemical interactions in the antibacterial behavior of ZnO nanoparticles against E. coli

“…•OH radicals, forming hydrogen peroxide [1,9,17,[32][33][34][35][36][37][38][39]. Therefore, it may be suggested that regarding the ROX effect, hydrogen peroxide and superoxide anion production from ZnO NPs would not produce salient antibacterial effect.…”

“…Superoxide anion radical is unlikely to cause any bactericidal effect as it is less toxic and is poorly permeating to cell membranes. [17,33,37,39,40].…”

Antimicrobial effect of titanium dioxide after ultraviolet irradiation against periodontal pathogen

“…ROS are strong oxidants that induce oxidative damage in the cell membrane and/ or cell wall of bacteria 13) . Generally, HO • can be detected by electron spin resonance spectroscopy (ESR) using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spintrapping agent 14) . Recently, there has been growing interest in the antimicrobial activity of photocatalytic effects 10) .…”

“…• production was detected by ESR spectroscopy as described previously 14) . DMPO (88 mM, Labotec, Tokyo, Japan) was used as the spin-trapping agent.…”

ESR investigation of ROS generated by H<Sub>2</Sub>O<Sub>2</Sub> bleaching with TiO<Sub>2</Sub> coated HAp

“…•-), and H2O2 are involved in the photocatalysis of TiO2 [14][15] . We have developed an in vitro electron spin resonance (ESR) method for detecting ROS, such as O2…”