Photocrosslinkable Antibacterial Bioadhesives Derived from Soybean Oil-Based Hydroxyurethane Methacrylates

Compared to traditional invasive techniques for wound closure, photocrosslinkable surgical adhesives with antibacterial properties offer significant advantages. These include ease of application, a controllable and efficient curing reaction, reduced risk of pain and infection, and effective leakage prevention. This study introduces a novel soybean oil-based nonisocyanate polyurethane prepolymer for use in such adhesives. The prepolymer, a hydroxyurethane functionalized with methacrylate and quaternary ammonium groups (QAs), was characterized through spectroscopic methods. The resulting UV-curable bioadhesives, synthesized via thiol-ene-methacrylate click-photopolymerization, incorporated limonene as a reactive diluent, a tetra-functional thiol crosslinker, and a photoinitiator. Elemental analysis confirmed the uniform distribution of QAs and sulfur atoms, indicating a homogeneous network structure, corroborated by high gel content values in both organic (84–92%) and aqueous media (91–99%), and a consistent tan δ peak as per DMTA. The optimized adhesives exhibited strong adhesion (up to 377 kPa) to gelatin sheets—a tissue-analogous substrate—and displayed suitable surface free energy (45–52 mN/m) as determined by contact angle measurements, suggesting favorable thermodynamic adhesion to skin. Additionally, the adhesives showed satisfactory cytocompatibility with L-929 fibroblast cells and antimicrobial efficacy against two gram-positive and gram-negative bacterial strains, indicating promising biological activity.