A bioinspired suction-activated nanofibrous patch for adaptive skin adhesion and enhanced transdermal delivery

Transdermal delivery offers a user-friendly and minimally invasive route to overcome limitations of conventional oral and injectable methods. Cellulose nanofibers (CNFs)-based skin-adhesive patches have emerged as promising platforms to enhance transdermal delivery efficiency owing to their biocompatibility and porous fibrous networks. However, the fabrication of CNFs-based patches that can withstand high-viscosity solutions while maintaining adaptive adhesion under deforming skin conditions remains challenging. Moreover, existing strategies to impart functionality often rely on complex and precision-intensive fabricating processes. Here, we present a CNFs-based transdermal patch (OIF patch) incorporating an octopus-inspired suction cup (OISC), fabricated via a straightforward imprinting process. Under optimized fabrication conditions (150 °C and 500 MPa), OIF patch maintains structural integrity without thermal degradation and demonstrates enhanced robustness in highly viscous environments. The imprinted OISC induces deformation-driven negative pressure, enabling intimate and adaptive skin adhesion even under bending deformation (up to 90°). Consequently, OIF patch demonstrates robust adhesion across diverse skin conditions and achieves up to a 350% enhancement in transdermal delivery depth compared to flat fibrous. Clinical evaluations further confirm improvements in multiple skin parameters, underscoring the translational potential of OIF patch. This work establishes a scalable and adaptable CNFs-based platform for reliable transdermal delivery under user-induced dynamic conditions.