Bioactive carboxylated PAN nanofiber membranes from expired egg white waste for antibacterial applications

Abstract

The rapid expansion of the egg industry has led to the accumulation of expired egg white waste, much of which remains underutilized and contributes to environmental pollution. Given the natural antimicrobial proteins in chicken egg white (CEW), such as lysozyme (LYZ) and ovotransferrin, repurposing expired CEW offers a sustainable strategy to reduce waste while addressing concerns about antibiotic resistance. In this study, polyacrylonitrile (PAN) nanofiber membranes were functionalized with −COOH groups via alkaline hydrolysis to facilitate protein attachment. Expired CEW was immobilized onto the modified membranes through weak ionic and covalent interactions, forming P-COOH-EWP (egg white proteins) nanofiber membranes. The membranes were characterized for surface morphology, chemical composition, and antibacterial activity against Escherichia coli and Staphylococcus aureus. Additional evaluations included enzymatic activity, cytotoxicity, reusability, and storage stability. The results confirmed successful immobilization of EWP. The P-COOH-EWP membranes demonstrated vigorous antibacterial activity, with 86.57 % efficacy against E. coli and 75.05 % against S. aureus, and showed excellent biocompatibility without cytotoxic effects. They retained more than 72 % antibacterial activity after four weeks of storage at room temperature. However, activity decreased by 40 % after two uses, indicating suitability for single-use applications. This work presents a cost-effective and environmentally friendly approach to valorizing expired CEW waste into functional antibacterial nanomaterials for biomedical, food packaging, and environmental applications.