Noninvasive transdermal delivery of mesoporous silica nanoparticles using deep eutectic solvent.

Transdermal delivery of solid nanoparticles remains a big problem. Microneedle administration and subcutaneous injection are the only two feasible approaches. Here, we developed a noninvasive strategy for the transdermal delivery of mesoporous silica nanoparticles (MSNs) using deep eutectic solvent (DES) from amino acid (AA) and citric acid (CA), which showed a substantial enhancement in skin penetration ability. MSNs were surface modified by CA and then reacted with Lysine (Lys) to form the DES-MSNs system. The covalent linkage of MSNs to the surrounding DES immobilized the nanoparticles and provided strong interactions. We used intradermal and transdermal penetration assays to identify that the AACA DES could synchronously drive the MSNs to penetrate across the entire skin via a "Drag" effect. Furthermore, this is the first study to detect the nanoparticles in the blood by topical administration routes. Thus, we achieved the transdermal delivery of the MSNs into blood circulation. This work would extend the application of the MSNs drug carrier system and provide a novel strategy for the controlled and sustained delivery of nanoparticles.