40nm, But Not 750 or 1,500nm, Nanoparticles Enter Epidermal CD1a+ Cells After Transcutaneous Application on Human Skin
TLDR Only 40 nm nanoparticles can enter skin cells effectively for potential vaccine delivery.
The study investigated the use of nanoparticles for transcutaneous vaccine delivery targeting antigen-presenting cells (APCs) in human skin. It was found that only 40 nm nanoparticles, not 750 or 1,500 nm ones, could penetrate deeply into vellus hair openings and the follicular epithelium, effectively entering epidermal Langerhans cells (LCs). This suggests that 40 nm nanoparticles could be efficiently used to deliver vaccine compounds via hair follicles into cutaneous APCs, potentially improving immune responses for chronic diseases like HIV and tuberculosis.
