Multifunctional "Janus-Type" Bilayer Films Combine Broad-Range Tissue Adhesion with Guided Drug Release

Tissue healing is a challenging process that requires the successful and simultaneous management of conflicting priorities. While promoting wound closure, a battle must be won against different external factors that may adversely affect the healing process. Here this problem is approached by creating asymmetrically designed double-layer Janus-type bilayer films where distinct functions are implemented into the two sides of the film. Once deployed, those Janus-type films exhibit strong adhesion to a wide variety of wet tissues and canalize the release of integrated therapeutics toward the tissue side. At the same time, the outer surface of the films acts as a shield against tribological stress, pathogens, and cellular immune recognition. Moreover, when compared to untreated wounds, Janus-treated skin lesions show accelerated wound closure as well as fast formation of new, intact tissue. Having performed their tasks, Janus-type films degrade without leaving any traces on the tissues, which makes it possible to apply them to sensitive body surfaces. Thus, it is expected that the Janus-type bilayer films designed here can be used in a variety of medical applications where conflicting demands must be met at the same time.