Skin barrier disruptions in tape stripped and allergic dermatitis models have no effect on dermal penetration and systemic distribution of AHAPS-functionalized silica nanoparticles

The effects of mechanical and inflammatory skin barrier disruptions on the penetration of N-(6-aminohexyl)-aminopropyltrimethoxysilane (AHAPS)-functionalized silica nanoparticles (SiO2-NP) were studied. Murine skin (intact, tape stripped or with allergic contact dermatitis) was treated topically with AHAPS-SiO2-NP for one or five consecutive days, respectively. In all cases, AHAPS-SiO2-NP accumulated in the cornified outer epidermal layer only. In contrast, following subcutaneous injection, the NPs were taken up by macrophages and partially transported to the regional lymph node but not beyond. AHAPS-SiO2-NP thus seem not to penetrate healthy or diseased skin.141