Enzyme Precipitate Coating of Glucose Oxidase on Electrospun Polymer Nanofibers with Efficient Antibacterial Activity

Polymeric nanofibrous materials in conjugation with antibacterial compounds such as antibiotics, metal nanoparticles have gained attention for the treatment of wounds, burns, post-surgical related problems to reduce microbial infections. In this study, we used electrospun polymer nanofibers consisting of polystyrene (PS) and poly(styrene-co-maleic anhydride (PSMA) for the immobilization of glucose oxidase (GOx) and horseradish peroxide (HRP) enzymes via three approaches, such as covalent attachment (CA), enzyme coating (EC) and enzyme precipitate coating (EPC). The EPC protocol consists of CA, enzyme precipitation and crosslinking while EC represents a control sample without the step of enzyme precipitation. GOx-catalyzed glucose oxidation generates hydrogen peroxide, which can kill both gram-positive and gram-negative bacteria, and the EPC sample showed much more potent antimicrobial activity than CA and EC due to its higher enzyme loading and stability. The antimicrobial potency is further enhanced by the supplement of potassium iodide as well as the addition of HPR-immobilized nanofibers. Further, EPC of GOx showed negligible decrease of antimicrobial activity under recycled uses. EPC with stabilized and highly-loaded enzymes has opened up its great potential as an environmentally-safe agent to kill bacteria.