US Forscher bestätigen: Nanopartikel in Sonnencremes durchdringen gesunde Haut nicht
Eine Gruppe bestehend aus Wissenschaftlern der US Food and Drug Administration (BFA) und des National Cancer Institute ist auf der Basis einer Untersuchung an Minischweinen zum Schluss gekommen, dass nanoskaliges Titandioxid in Sonnencremes die gesunde Haut nicht durchdringen dürfte. Diese Erkenntnis bestätigt bereits bestehende Befunde aus früheren Untersuchungen, spricht aber das Problem bei verletzter oder anderweitig beeinträchtigter Haut nicht an.
Their study, "Lack of Significant Dermal Penetration of Titanium Dioxide (TiO2) from Sunscreen Formulations Containing Nano- and Sub-micron-sized TiO2 Particles," published Feb 15 in Toxicological Sciences, helps to address concerns that nanoscale ingredients could cause harm to people if absorbed into the skin.
The team tested three different preparations of titanium dioxide particles by spreading them on the skin of minipigs for 22 days. Isolated titanium particles were found to be present at various locations in the dermis of the minipigs treated with the TiO2-containing sunscreens. However, according to the authors of the study, "there was no pattern of distribution or pathology suggesting the particlescould be the result of contamination. At most, the few isolatedparticles represent a tiny fraction of the total amount of applied TiO2."
The study’s authors wrote that, "This study supports the conclusion that nano-sized TiO2 included in a formulation similar to currently marketed sunscreens does not significantly penetrate intact normal pig skin to any significant degree, and therefore is unlikely to significantly penetrate human skin."
The authors noted that the study did not rule out the possibility of adverse effects on damaged skin. Concerns have been raised that the sunscreen nanoscale particles might penetrate the horny layers of the epidermins if the skin is already sunburned, flexed or mechanically impaired (excoriated, wounded).
Source: Adapted from Meridian Nanotechnology & Development News
The full study can be accessed here: http://toxsci.oxfordjournals.org/cgi/content/short/kfq041v1?rss=1