Bioinspired Transdermal Delivery Patches with Multiscale Adhesive Architectures

Intelligent bioinspired adhesive devices are attracting attention as a tool for the transdermal drug delivery patch. However, there have been many challenges in delivering drugs from the wrinkled and rough skin surface through the complex stratum corneum into the body. The rough skin surface interferes with the interfacial contact between the drug delivery material and the skin, making close adhesion difficult, which reduces drug delivery efficiency. In addition, the brick-like structure of the stratum corneum, which has a barrier function, is a major obstacle to drug delivery through the skin. Here, we present two strategies to overcome the limitations of transdermal drug delivery based on biomimetics. First, the drug delivery patch, which is designed by combining an adhesive structure that mimics a diving beetle and a drug-loading hydrogel, improves the efficiency of drug delivery through conformal contact. In addition, the asymmetric diving beetle adhesive structure provides directional adhesive performance, enabling hypoallergenic detachment. Second, it is an adhesive interface that provides negative pressure to the skin by mimicking the tentacle of a cephalopod. Negative pressure delivered to the skin induces fine structural deformation of the stratum corneum and creates gaps between the stratum corneum, improving drug delivery efficiency. With the aid of bioinspired adhesive architecture, we demonstrated improved drug delivery efficiency in an <i>in vivo</i> model, suggesting a promising development in the medical and skin therapy fields.