Development and evaluation of zinc phthalocyanine nanoemulsions for use in photodynamic therapy for Leishmania spp.

Photodynamic therapy (PDT) combines light with photosensitizers (PS) for production of reactive oxygen species (ROS) that can kill infectious microorganisms such as bacteria, fungi and protozoa. The application of nanotechnology has enabled the advancement of PDT because many PS are insoluble in water, necessitating a nanocarrier as a physiologically acceptable carrier. Nanoemulsions are efficient nanocarriers for solubilizing liposoluble drugs, like the PS, in water.

Nanosystems in Photoprotection.

The ultraviolet (UV) radiation is responsible for stimulating acute responses in the human skin, those including positive responses like vitamin D synthesis along with negative ones such as erythema. The chronic effects of UV radiation include photoaging and cancer. Sunscreens are classified as organic and inorganic and the safety of the products containing them is related to the evaluation of the effects of these actives on the skin (irritation and sensitization) and also the possibility of cutaneous permeation that may cause the product to permeate into the bloodstream, possibly generating systemic toxicity.