Ciprofloxacin-loaded electrospun nanofibres for antibacterial wound dressings

Abstract

A wound is an injury that damages the normal structure and function of the skin and the underlying tissue. Disruption of the wound healing process causes chronic wounds, which are usually associated with microbial infections. In this work, ciprofloxacin was loaded into electrospun nanofibres to generate antibacterial wound dressings. Electrospun nanofibres are suitable for wound dressings due to their adaptability to the wound contour, high porosity for gas exchange, and a high surface area for absorbing wound exudate. Ciprofloxacin was successfully incorporated in polyvinyl alcohol (PVA) and PVA/alginate-blended electrospun nanofibres, with mean diameters ranging from 258 to 460 nm. The materials were characterized using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) to examine the thermal properties and physical form of the drug and polymers. Fourier transform infrared spectroscopy (FTIR) was used to characterise intermolecular interactions within the materials. DSC thermograms showed all the fibres have a PVA enthalpy relaxation peak at 47 °C and a PVA melting endotherm at 229 °C. The XRD patterns indicated decreased crystallinity of PVA after electrospinning. No crystalline drug could be detected in the fibres by either XRD or DSC. FTIR spectra showed the formation of hydrogen bonds between PVA and alginate in the fibres. All the electrospun nanofibres have high water uptake capacity (190%–381%). The ciprofloxacin-loaded electrospun nanofibres also have high drug encapsulation efficiency, above 90%. The drug release profiles demonstrated controlled-release of the drug, following the Korsmeyer-Peppas model. The antibacterial efficacy of the nanofibres was evaluated by isothermal microcalorimetric assays, with the ciprofloxacin-loaded nanofibres found to exhibit equivalent antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa to pure ciprofloxacin. Hence, the fibres fabricated in this work have the potential to be used as advanced systems to prevent infection during wound healing.