Seminari IQAC - Dimarts 17 de Juliol a les 15:30 a la Sala d'Actes impartit per la Dra. Alexa Patzelt de la Universitätsmedizin Berlin

Nanocarriers (NC) are frequently used for drug delivery in several application fields of medicine. Also in dermatology, there is a lot of scientific effort to develop NC for the transport of topically applied drugs through the skin barrier. However, more and more investigations confirm that NC are not able to overcome the intact skin barrier via the intercellular penetration pathway under in vivo conditions. Some of these investigations, however, showed that these NC preferentially accumulate within the hair follicles (HF). This process of follicular penetration of NC seems to be mainly mechanically driven as especially NC of a size of around 600 nm showed the highest follicular penetration depths. In silico modeling compared the follicular penetration process with a ratchet mechanism where the moving hair helps to transport the NC deeply into the HF. Here, NC size and frequency of hair movement mainly seem to determine the effectiveness of the follicular penetration process. Once accumulated deeply into the HF, the NC are likewise not able to overcome the follicular barrier to get access to the viable epidermis, the circulation or other target structures. Therefore, a new approach in the form of smart NC is required, which are able to release their active agents subsequent to a certain trigger stimulus within the HF. As soon as these active agents are released they are able to overcome the follicular barrier independently. First investigations demonstrated this new approach to be very effective but further studies have to follow to establish this new promising concept of drug delivery. Currently, new methods are developed to investigate and quantify the transfollicular penetration process of the active substances released within the HF from the smart NC systems.

 

Dr. med. Alexa Patzelt graduated in medicine and received the doctor’s degree in 2004 at the Humboldt University of Berlin, Germany. Dr. Alexa Patzelt commenced her residency in dermatology at the Department of Dermatology, Venerology and Allergy, Charité – Universitätsmedizin Berlin, Germany. She received her specialization in dermatology in 2009. Since then, she has been advancing her scientific work with the main focus being on basic research of follicular penetration of topically applied substances, inverse penetration of systemically applied substances, topical vaccination and skin barrier investigations.