Core-shell nanotransporters for the skin

Abstract

Besides native dendrimer nanoparticles, those with advanced surface modifications are tested for topical use in skin diseases, yet at a preclinical level. These nanoparticles include core-multishell (CMS) nanotransporters which are dendrimers covered by a lipophilic inner shell and a hydrophilic/amphiphilic outer shell. CMS nanotransporters are loadable by hydrophilic and lipophilic guest molecules due to supramolecular interactions. Moreover, agents can be covalently attached to functional groups of the particle core. CMS nanoparticles can deliver their payload most efficiently to viable human skin ex vivo. A higher amount of the loaded agent passes the stratum corneum barrier compared to conventional vehicles and efficacy exceeds that of lipid nanoparticles, too. First data on the safety of this system are promising, yet in vivo studies are to be awaited. Another advanced system is the tecto-dendrimer, where a dendritic core is covered by a dendritic shell. A recent in vitro study indicates the potential of this nanoparticle type for the delivery of methotrexate. The unloaded tecto-dendrimer and when loaded with methotrexate induced selective toxicity in a melanoma cell line and proved less toxic to human keratinocyte and enterocyte cell lines. Once more, this effect has to be verified in vivo.