Antibacterial polyurethane adhesives for medical applications

Abstract

In this study, polyurethane prepolymers and two-component adhesive systems with antibacterial properties were synthesised and characterised for potential biomedical applications as tissue adhesives. The developed materials were designed to operate in moist biological environments and to provide simultaneous adhesive and antibacterial functions. The viscosity of the obtained prepolymers, measured using a Brookfield viscometer, ranged from 2.30 to 3.36 Pa·s, indicating favourable rheological properties for dosing, mixing, and application on tissue surfaces. The chemical structure of the crosslinked adhesives was confirmed by FTIR spectroscopy, which revealed characteristic urethane bands and the absence of isocyanate groups, indicating complete conversion during curing. Contact angle measurements demonstrated the hydrophilic nature of the materials, suggesting good potential for adhesion to wet biological tissues. Mechanical characterisation showed medium hardness (medium-soft materials) and high adhesive strength exceeding 5 MPa, confirming suitable mechanical performance for tissue bonding applications. Antibacterial testing indicated that the incorporation of a biopolymer-based antimicrobial agent resulted in strong biocidal activity, outperforming conventional silver-based additives. The results demonstrate that the developed polyurethane-based adhesive systems combine favourable mechanical, physicochemical, and antibacterial properties, making them promising candidates for surgical applications.