Genipin based green chemistry immobilization cascade towards enzyme based antibacterial biomaterial surfaces

Biomedical implants are highly susceptible to rapid bacterial colonization and biofilm formation, a major cause of implant failure and postsurgical complications. Although current antibacterial approaches commonly rely on metal-ion release or reactive oxygen species, these strategies may induce cytotoxicity or oxidative stress, underscoring the need for safer, biobased alternatives. Here we present a fully aqueous and green chemistry immobilization cascade to endow biomaterial surfaces with stable enzymatic antibacterial activity. Titanate assisted organosilanization provides an aminated surface onto which genipin, a low toxicity natural crosslinker, is covalently linked, enabling the immobilization of two antibacterial enzymes: lysozyme and α-amylase. Functionality assays reveal that genipin crosslinked lysozyme significantly reduces Clostridium perfringens viability, while α-amylase retains its catalytic activity, yielding sustained D-glucose production from maltose. L929 fibroblast cells exposed to 100% extracts obtained from the surfaces at different stages of enzymatic immobilization remained viable (≥80%) even for longer incubation periods (72 h). Altogether, this study establishes a mild, solvent free and biobased immobilization route capable of producing stable enzyme-functionalized surfaces, offering a versatile platform for future development of antibacterial biomaterial coatings.