Selective Follicular Targeting by Modification of the Particle Sizes

The study, using porcine skin as a model, demonstrated that medium-sized particles (643 nm for PLGA and 646 nm for silica) penetrated hair follicles more effectively than smaller or larger particles, suggesting a selective targeting capability based on particle size. This penetration may be facilitated by the keratin cells acting as a pump for particles within the 400 to 700 nm range. While the results are expected to be similar in human terminal hair follicles due to size similarities, they may not hold for the smaller human vellus hair follicles. The findings, supported by the Foundation “Skin Physiology" of the Donor Association for German Science and Humanities, have implications for the delivery of therapeutic and cosmetic substances through the skin.