Vigilancia Tecnológica

Biocompatible, bistable or multistable (P-Type) photochromic or UV-absorbing nanoparticles or microparticles can be applied topically to the skin. The color of the topical body ink using the biocompatible and biodegradable bistable or multistable photochromic microparticles can be written, erased or changed, and re-written locally on the skin by irradiation with light of appropriate wavelengths. Formulations with much higher sensitivity to UV light than visible light can be used as short-term topical colorimetric UV dosimeters that can be reset and re-used on an hourly or daily basis. The topical body ink using the biocompatible UV-absorbing nanoparticles or microparticles provides skin protection against sunburn, photoaging, and skin cancers in a permanent or semi-permanent way, but remain clear in the visible light spectrum, or matched closely to the user's skin tone. These particles can be uniform aggregates or polymers containing P-type photochromic dyes or UV-absorbers, microencapsulated or core-shell structures, or solid particulate materials.