Poly(propylene fumarate)-Based Adhesives with a Transformable Adhesion Force for Suture-Free Fixation of Soft Tissue Wounds br

The design of soft tissue adhesives with excellent adhesive performancehas drawn much attention in biomedical applications for the suture-freefixation of softtissue wounds. Poly(propylene fumarate) (PPF)-based materials exhibit excellentbiocompatibility with nontoxic products and high mechanical strength and are widelyused as bone repair materials. However, shortcomings, including low adhesive strength,low breathability, and poor hydrophobicity, as well as difficulty in detaching in vitro ordegrading in vivo after wound tissue healing, limit the potential application of PPF-basedmaterials in soft tissue adhesives. This study presented a biomimetic nucleobase-tackifiedstrategy for designing PPF-based soft tissue adhesives, where adenine was diffuselydistributed as a convex second phase in the PPF matrix and provided multipointinteractions with soft tissues. As a result, adenine increased both the lap shear strengthby 200% (1.48 +/- 0.10 MPa) and the adhesive strength (1.70 +/- 0.08 MPa) by 45% in theearly stage, and then with adenine degradation, the multipoint interactions disappearedand simultaneously achieved a removable adhesion function with tissue. Moreover, theformed microscale pores from the adenine degradation site also improved the maximum moisture vapor transmission rate by 238%and the hydrophilicity. This detachable adhesive strategy on PPF-based materials will significantly promote the next generation of soft tissue adhesives for biomedical applications.