PLA/β-CD-based fibres loaded with quercetin as potential antibacterial dressing materials

Microbial infections lead to elevated inflammatory responses, which usually result in prolonged and incomplete wound healing. Therefore, there is an increasing demand for biodegradable fibres that are effective against a different range of microorganisms, especially those with antibiotic resistance. Herein, quercetin-(Q)-loaded polylactide-based fibres were developed using the electrospinning technique. Since Q exhibits low chemical stability, we used star-shaped polylactides (PLAs) with a β-CD core to host Q by inclusion complexation. To enhance the stability of the fibres and additionally entrap the Q between polymeric chains, we adapted supramolecular cross-linking by the stereocomplexation of PLAs with opposite configurations. As a control, we prepared an additional formulation of star-shaped/commercial PLA/Q for the preparation of nonwovens in which the β-CD moiety was not present. All developed fibres were smooth and continuous, with an average diameter of 37 μm. Although nonwovens did not possess diffusible activity, good antibacterial effects against Staphylococcus aureus ( S. aureus ), Escherichia coli ( E.coli ) and Klebsiella pneumoniae ( K. pneumoniae ) were observed. All these features validate the proposed approach, in which different supramolecular interactions were used to modify the properties of PLA-based fibres and, most importantly, show their great potential usefulness against microbial infections.