Modification of electrospun poly(ε-caprolactone) mats by formation of a polyelectrolyte complex between poly(acrylic acid) and quaternized chitosan for tuning of their antibacterial properties

Novel antibacterial nanofibrous mats from poly(ε-caprolactone) (PCL) were prepared using the formation of polyelectrolyte complex as a tool for tuning the properties of the mats. Two approaches were applied: (i) coating the surface of PCL mats with crosslinked poly(acrylic acid) (PAAcr) followed by the formation of a polyelectrolyte complex (PEC) with N,N,N-trimethylchitosan iodide (TMCh) and (ii) grafting of PAA on the surface of PCL mats and subsequent PEC formation between grafted PAA and TMCh. The formation of PEC-based coating on the fiber surface was demonstrated by means of scanning electron microscopy (SEM), attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The microbiological screening revealed that in contrast to the pristine PCL mats, the PEC-coated PCL mats are effective in inhibiting the growth of the Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli as well as in suppressing the adhesion of pathogenic bacteria S. aureus.