Multifunctional “Janus‐Type” Bilayer Films Combine Broad‐Range Tissue Adhesion with Guided Drug Release

Abstract

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.

Prevention strategies of postoperative adhesion in soft tissues by applying biomaterials: Based on the mechanisms of occurrence and development of adhesions

“…Constructing double-layer or multilayer materials with excellent structural stability is the most used strategy. Among them, Janus porous hydrogel [ 175 , 288 ], hydrogel-electrospinning system [ 177 ], electrospinning-electrospinning system [ 334 ], electrospinning-cast film system [ 335 ], electrospinning-sheet system [ 336 , 337 ], sponge-hydrogel system [ 338 ], aerogel-electrospinning system [ 339 ] and layer-by-layer surface coating [ 340 ] show superiority and need wider application and research. In addition, the surface coating technology such as “hydrogel skin” [ 219 , 341 ] exhibited priority.…”

Gradient Modulus Tissue Adhesive Composite for Dynamic Wound Closure

“…Similar layer by layer strategies were reported for the design of advanced patches for wound management. [44][45][46][47][48] A bilayer adhesive wrap was developed with selective bioactivity to simultaneously prevent intraabdominal adhesion and promote anastomotic healing. [44] Doublelayer Janus films [46] or multilayer bio-adhesive patches [47] with a biofouling resistant outer surface were designed for strong adhesion wet tissue surfaces.…”

“…[44][45][46][47][48] A bilayer adhesive wrap was developed with selective bioactivity to simultaneously prevent intraabdominal adhesion and promote anastomotic healing. [44] Doublelayer Janus films [46] or multilayer bio-adhesive patches [47] with a biofouling resistant outer surface were designed for strong adhesion wet tissue surfaces. Recently, an off-the-shelf multilayer patch was reported for sealing gastric tissue defects, [48] which was composed of a nonadhesive top layer as the mechanical reinforcement and a dry bioadhesive bottom layer for robust adhesion on gastric tissue.…”

Bio‐Macromolecular Surface Coatings for Autohesive, Transparent, Elastomeric Foils

“…Torsion Tests: For torsion measurements, the rheometer was equipped with a measuring shaft for disposable measuring heads (CP/DP70, Anton Paar). To both, the sample holder unit and the measuring shaft, an in-house manufactured aluminum clamp was attached as described in Kimna et al [39] Both clamps were positioned in a parallel orientation, and a foil sample (5 mm x 10 mm) was fixated such that the free length of the samples was always comparable (≈12 mm). The normal force was reset, and the top clamp was moved upwards to pre-stretch the sample until a normal force of −0.3 N was achieved.…”