Biocompatible antimicrobial electrospun nanofibers functionalized with ε-poly-l-lysine

Abstract

The antimicrobial polypeptide ε-poly(l-lysine) (ε-PL) was electrostatically incorporated to poly(acrylic acid) (PAA)/poly(vinyl alcohol) (PVA) electrospun nanofibers. ε-PL loading and distribution was assessed by infrared spectra, ζ-potential measurements and the primary amino reactive dye fluorescamine. Functionalized fibers with 485 ± 140 nm diameter, could be loaded with 0.57-0.74 g ε-PL (g dressing)^-1 that released at a constant rate of 5.4 ± 2.8 mg ε-PL (g dressing day)^-1. Such a dressings resulted in two orders of magnitude lower bacterial colonization than non-functionalized PAA-PVA after 14 days of incubation. Bacterial impairment was attributed to the damage of cell membranes and the formation of intracellular reactive oxygen species. ε-PL functionalized nanofibers did not display cytotoxicity to human corneal epithelial cells, HCEpC, in 24 h MTT assays. However, the viability of rapidly growing tumoral HeLa cells decreased >50% under the same conditions. The prepared biocompatible nanofibrous dressings with durable antibacterial activity show potential application as wound dressings and other biomedical uses.

Keywords: Antibacterial materials; Biocompatible dressings; Electrospun fibers; ε-Poly(l-lysine).