Fullerene-C60 derivatives prevent UV-irradiation/ TiO2-induced cytotoxicity on keratinocytes and 3D-skin tissues through antioxidant actions

J Nanosci Nanotechnol. 2014 May;14(5):3285-91. doi: 10.1166/jnn.2014.8719.

Abstract

Microcorpuscular titanium dioxide (TiO2), a useful sunscreen agent, photocatalyzes generation of reactive oxygen species (ROS). We assessed protective effects of fullerene-C60 derivatives or microcolloidal platinum (Pt) against ultraviolet ray (UV)-irradiation in the presence of TiO2 in vitro. UV-irradiation (8 J/cm2, mixed UVA and UVB) in the presence of 15 ppm TiO2 on HaCaT keratinocytes decreased cell viability as quantified by WST-1 assay, and increased both intracellular ROS and cell-membrane-lipid peroxidation, as quantified by nitroblue-tetrazolium (NBT) assay and diphenyl-1-pyrenylphosphine (DPPP) assay, respectively, whereas all of three phototoxicity-related symptoms were appreciably repressed almost to UV-unirradiational levels by pretreatment with polyvinylpyrrolidone-entrapped fullerene-C60 (C60/PVP) or fullerene-C60 dissolved in squalane (C60/Sqn) in a dose-dependent manner of C60, but scarcely by PVP alone or Sqn alone. In contrast, Pt repressed intracellular ROS generation, but did not prevent either peroxidation of cell-membrane-lipid or cell mortality. Then in the epidermis of 3-dimensional human skin tissue model, UV-irradiation in the presence of TiO2 extensively induced two symptoms such as ROS-generation around perinuclear regions and membrane-lipid peroxidation, both of which were repressed by C60/PVP or C60/Sqn, whereas Pt did not prevent membrane-lipid peroxidation adequately. Thus the advantageous application of the lipophilic antioxidant fullerene-C60 which effectively protects cell membrane against peroxidation. In conclusion, fullerene-C60 can be expected to serve as an antioxidant for scavenging of TiO2-photocatalyzed ROS in the skin surface, and therefore provide a functional improvement of TiO2-containing sunscreens.

MeSH terms

  • Antioxidants / pharmacology*
  • Cell Line
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • Fullerenes / pharmacology*
  • Humans
  • Keratinocytes / drug effects*
  • Keratinocytes / metabolism
  • Keratinocytes / radiation effects*
  • Lipid Peroxidation / drug effects
  • Lipid Peroxidation / radiation effects
  • Reactive Oxygen Species / metabolism
  • Titanium / toxicity*
  • Ultraviolet Rays*

Substances

  • Antioxidants
  • Fullerenes
  • Reactive Oxygen Species
  • titanium dioxide
  • Titanium
  • fullerene C60