Non-invasive delivery of nanoparticles to hair follicles: A perspective for transcutaneous immunization

► We investigated transfollicular vaccination via intact skin using nanoparticles(NP). ► Polymeric NP from PLGA+- chitosan were loaded with ovalbumin (OVA). ► OVA/NP stimulated proliferation of CD4+ &/or CD8+ T-cells more than OVA/solution. ► NP improved (×2-3) follicular delivery of OVA on pig ears compared to OVA/solution. ► Consequently using OVA/NP one may reduce the dose compared to OVA/solution.