Fabrication of Novel Antimicrobial Bio-Fibers Using Silk Wastage,Study of Poly (hexamethylene) Biguanide,and Silver Nanoparticles Interaction

Regenerated silk fibers were fabricated through dry-wet spinning process using N-methyl morpholine N-oxide and methanol as solvent and coagulant, respectively. Several concentrations of poly (hexamethylene) biguanide (PHMB) (0.27, 0.41, and 0.55 mL per 1 g of fibroin) and silver nanoparticles (AgNPs) (0.0005, 0.0015, 0.0055, 0.0095, and 0.0135% (w/v) were used as antibacterial agents. Antibacterial property of bio-fibers produced by either master batch or dipping methods was compared to each other against a gram-positive bacterium, Staphylococcus aurous. Master batch process indicated the dependency of antibacterial effect on the concentration of antibacterial agents as well as particle size. Maximum bactericidal activity in this process was obtained at concentrations of 0.0055% of AgNPs and 0.55 mL of PHMB per 1 g of fibroin. However for long-lasting effect and from toxicity aspect PHMB with lower concentration (0.27 mL) and with 0.0055% AgNP was seemed to be ideal. The result from dipping process showed that various concentrations of PHMB can greatly influence on the results; the interaction of 0.0055% AgNPs and 0.41 mL of PHMB offered good antibacterial properties with the least amount of toxicity effect in human cells.