Enzymatic Crosslinking of Coacervates Yields High‐Strength and Reconstitutable Biomedical Adhesives

Biomedical adhesives are emerging as an effective wound treatment option. The current cyanoacrylate or fibrin-based adhesives falter in either being ineffective in high moisture regions due to their hydrophobic character or producing very weak adhesion due to rapid degradation in the biological milieu. To overcome these impediments in the practical application of biomedical adhesives, water-based biomedical adhesives are prepared through enzymatic crosslinking of polyelectrolyte complexes (PECs) that not only offer high adhesion strength but also work well in high relative humidity environments and sustain during the wound healing process. The adhesive is prepared from oppositely charged polyelectrolytes (PEs) having a polyamide backbone and containing ca. 25 mol% phenolic pendants as the Horseradish Peroxidase (HRP)-responsive residues. Excellent formulation stability, rapid curing, optical clarity of the adhesive layer, and high-strength adhesion of diverse substrates are the key advantages of this PEC adhesive. The strongest adhesion is found for wood with adhesive strength up to 10 MPa. The adhesive can be lyophilized to a powder form and reconstituted, fully retaining its adhesive performance. It is hemostatic and exhibited a promising surface wound-healing outcome in mice, significantly outperforming the commercial cyanoacrylate-based tissue adhesives. These findings position the enzyme-cured PEC adhesives as a promising contender in advanced wound care applications.