Acrylic Acid Polymer Coatings on Silk Fibers by Room-temperature APGD Plasma Jets

The aim of this work is to coat silk fibers (SF) with polymer of acrylic acid (PAA) using an atmospheric pressure glow discharge (APGD) plasma jet in order to immobilize antimicrobial peptide LL-37. The polymer properties are characterized by contact angle goniometry (CAG), XPS, AFM and SEM. The CA of the SF film can be decreased to 340, and the surface roughness of PAA in the center of plasma jet is larger than in other areas. Compared with the original SF, the concentration of carboxyl group increases greatly when the SF are modified by Ar plasma jet polymerization of AA. The augmentation of functional groups is very useful to immobilize larger concentrations of microbial peptide LL-37 on the SF surface, and the satisfactory antimicrobial activity on inhibiting the Escherichia coli (E. coli) is thereby achieved.