Immobilization of poly(hexamethylene biguanide) to cellulose acetate- and cellulose-based nanofiber membranes for antibacterial and cytotoxic studies

To develop the environmental antibacterial membrane, the physical attachments of poly (hexamethylene biguanide) hydrochloride (PHMB) on the cellulose acetate (CA) and regenerated cellulose (RC) electrospun nanofiber membranes were employed. The immobilization of PHMB increased the antibacterial efficacy (AE, %) of nanofiber membranes from 65.67% to approximately 86.13% for CA-PHMB and from 35.09% to approximately 100% for RC-PHMB. The results of the chemical and physical characteristics indicate that the degree of deacetylation of CA nanofiber, the surface charge of the nanofiber, and the density of PHMB immobilized onto the nanofiber primarily affect the antibacterial efficacy. The use of mathematical models, such as the Temkin equilibrium model for PHMB immobilization and the Monod-type model for the relationship between antibacterial activity and immobilization density of PHMB provides a deeper understanding of the interactions and kinetics involved. The rapid achievement of ∼100% AE after only 10 min of contact with Escherichia coli (E. coli) is a notable finding, indicating the quick and efficient antibacterial action of RC-PHMB nanofiber membranes. Furthermore, maintaining approximately 100% AE after 20 days of storage underscores the long-term stability of PHMB immobilized on RC nanofiber membranes. The findings suggest that RC-PHMB holds great promise as an antibacterial material for biomedical applications, food packaging industries, and filtration or treatment of water.