Modified TiO(2) particles differentially affect human skin fibroblasts exposed to UVA light

Area of Science:

• Materials Science
• Photochemistry
• Dermatology

Background:

• Titanium dioxide (TiO(2)) is a common UV-filtering ingredient in sunscreens.
• TiO(2) can generate reactive oxygen species (ROS) under UV light, necessitating chemical modification for sunscreen use.

Purpose of the Study:

• To evaluate the in vitro photocatalytic effects of five modified TiO(2) particles used in sunscreens.
• To determine how particle modification and crystal form influence TiO(2)'s interaction with biological systems under UVA exposure.

Main Methods:

• In vitro testing using cultured human skin fibroblasts (HuDe).
• Assays included DPPH radical photobleaching, deoxyribose photodegradation, cell viability, DNA damage assessment, and intracellular ROS measurement.
• Exposure to UVA radiation was a key experimental condition.

Main Results:

• The modification type and crystal structure of TiO(2) significantly influenced its photocatalytic activity.
• Some modified TiO(2) particles induced DPPH radical photobleaching and deoxyribose photodegradation.
• Effects on cell viability, DNA damage, and intracellular ROS varied depending on the specific TiO(2) particle tested.

Conclusions:

• Certain modified TiO(2) particles retain photocatalytic activity, posing potential risks to skin cells.
• The anatase crystal form of TiO(2) was particularly associated with retained photocatalytic effects.
• Findings contribute to understanding the cellular-level effects of TiO(2) nanoparticles, especially if skin penetration occurs.