Antibacterial and Antifouling Polymer Brushes Incorporating Antimicrobial Peptide

Abstract

Surface-initiated atom transfer radical polymerization (ATRP) has been used to prepare antifouling copolymer brushes based on 2-(2-methoxyethoxy)ethyl methacrylate (MEO(2)MA) and hydroxyl-terminated oligo(ethylene glycol) methacrylate (HOEGMA). The amount of hydroxyl reactive groups incorporated into the brushes was varied by changing the composition of the monomer mixture. These coatings were subsequently functionalized by a natural antibacterial peptide, magainin I, via an oriented chemical grafting on hydroxyl groups, which maintains the activity of the peptide. The antibacterial activity of the functionalized brushes was successfully tested against two different strains of gram-positive bacteria.

Covalent immobilization of antimicrobial peptides (AMPs) onto biomaterial surfaces

“…In order to avoid implant-associated infections, several strategies have been reported with the aim of creating antimicrobial surfaces, such as the development of (i) non-fouling surfaces (surfaces that avoid protein adsorption and cell adhesion) [1,[18][19][20], (ii) surfaces previously colonized with non-pathogenic bacteria [9], (iii) surfaces combined with biocidal substances [21][22][23] and (iv) surfaces combined with antibiotics [24][25][26].…”

“…Humblot et al [68] reported that the immobilized AMPs had a bacteriostatic rather that bactericidal effect, perhaps due to the low peptide concentration or short contact time. Other research has performed the immobilization through long linkers in an attempt to permit sufficient flexibility to penetrate target cell membranes [1,69,70], as the directly attached AMPs lost their antimicrobial activity. Hilpert et al [71], in their screening and characterization of surface-tethered cationic peptides studies, reported that the immobilization of peptides to a surface should result in constraints on the peptide mobility and on the capacity of peptides to enter or even transpose the cellular membranes.…”

“…Other important activity-modulating parameters include the length, flexibility and kind of spacer between the active sequences and the solid matrices [67,69,70], the AMP surface density [1,68,69], and orientation after immobilization [1,11,[67][68][69][70][76][77][78]. These parameters are discussed below.…”

“…A wide variety of solid supports has been assessed for production of surfaces with immobilized AMPs, including polymeric brushes and resins [1,56,67,69,71,77,78], metal (e.g. silanized titanium) [70], glass coverslips [76], model surfaces (e.g.…”

“…Although infection incidence has been reduced by aseptic surgical techniques and prophylactic systemic antibiotic therapy, bacterial colonization of medical devices or implants still represents a serious hazard [1][2][3]. Mortality attributable to such infections is highest among patients with cardiovascular implants, particularly prosthetic heart valves and aortic grafts.…”