Nanocarriers for promoting skin delivery of therapeutic agents

Compared to oral and injectable administration, a dermal and transdermal drug delivery system that can deliver therapeutic molecules to desired target sites with noninvasive, low toxicity, and convenient self-application is a unique method with high potential and excellent prospects. However, the poor skin uptake rate of therapeutic agents has always been a principal challenge when effective therapy is the primary concern. During past decades, nanocarriers (NCs) composed of biocompatible lipids, polymers, or inorganic materials have been deemed a potential desirable and safe percutaneous penetration enhancer. With the assistance of nanotechnology, the dermal and transdermal penetrability, as well as the scope of topical therapeutic agents, have been augmented to provide more effective percutaneous treatment and enable the use of previously unsuitable substances (such as insulin, nucleotide, protein, and vaccine) in topical skin administration. This overview provides a detailed description of the classification, composition, examples, and possible mechanisms of NCs applied in dermal and transdermal drug delivery.