Functionalization of hydrophobic polymeric surfaces with laccase enzyme and antimicrobial peptides

Design of material surfaces functionalized with bioactive compounds has seen a rapid growth in industries such as biomedical, textiles, microelectronics, bioprocessing and food packaging in the last decade. In the field of biomaterials there is a broad need to render functionalization to prevent the bacterial surface attachment and growth to avoid infections and devices failure (1). A novel surface immobilization strategy of antimicrobials peptides containing L-3,4-dihydroxyphenylalanine (DOPA) in their peptide sequence and laccase enzyme on hydrophobic surfaces as HOPG and commercial polymers as polystyrene are presented. The laccases are phenol.oxidases that can catalyze reactions which include covalent coupling to form dimers, oligomers and polymers through C-C, C-O and C-N bonds and degradation of polymers by the cleavage of covalent bonds especially alkyl-aryl (2). The surface modification due to the contact with the laccase, peptide and peptide/laccase solutions were characterized by means of contact angle measurements, X-ray photoelectron spectroscopy, quartz crystal balance with dissipation, time-of-flight secondary ion mass spectrometry and atomic force microscopy. Two kinds of DOPA containing peptides were studied: with antimicrobial properties (amphiphilic) and with a hydrophilic sequence to study the influence of the laccase in the immobilization (3). The surface is modified with rigid and stable layers composed by laccase and DOPA peptide molecules, which change the surface properties to more hydrophilic domains, improving the fibroblast adhesion and antimicrobial properties against E.Coli of the material surface.