RESUMO
Although its antiviral and antibacterial functions help prevent infection, singlet oxygen (1 O2 )-which is generated by the action of light on an endogenous photosensitizer-is cytotoxic. In the present study, we investigated the ability of 1 O2 -generated by the action of visible light on a photosensitizer-to penetrate skin. We used two polymer films with oxygen permeability coefficients similar to that of skin-i.e. cellulose acetate (CA) and ethyl cellulose (EC). Both films contained 1,3-diphenylisobenzofuran (DPBF), which was used as an 1 O2 probe. 1 O2 generated externally did not permeate the films by mere contact. Therefore, we conclude that the potential for 1 O2 to penetrate the skin is very low, and films that generate 1 O2 are safe and useful for preventing infections by contact. We also proved that 1 O2 can move between the layers of integrated polymer films when they are joined together.