Delivery and Targeting of Nanoparticles into Hair Follicles

The document from September 1, 2014, reviews the use of nanoparticles for targeted drug delivery into hair follicles, which could improve treatment for skin diseases, including alopecia, acne, and enable transcutaneous immunization. Nanoparticles such as polymeric nanoparticles, metallic nanocrystals, liposomes, and lipid nanoparticles are discussed for their ability to penetrate hair follicles deeply and remain there longer than in the stratum corneum, potentially allowing for sustained drug delivery. Studies have shown that nanoparticles can accumulate in follicles, with size being a crucial factor for penetration depth. The document also explores the use of nanoparticles for systemic absorption and vaccination, with findings suggesting that nanoparticles can diffuse deep into follicles and be internalized by antigen-presenting cells. However, the role of hair follicles in total nanoparticulate penetration is less than 5%. The document concludes that while nanoparticle-based delivery systems show promise for dermatological treatments, more quantitative evaluation and understanding of cellular mechanisms are needed for future advancements.