Optimization of the Electrospinning Process to Create an Active Bilayer Nanostructured Wound Dressing Based of PLA and Ibuprofen

Abstract

A new bilayer wound dressing structure has been developed by depositing amorphous polylactic acid (PLA) nanofibers on a hydrogel layer composed of gelatin (GE), hyaluronic acid (HA) and zinc oxide (ZnO) particles for its antibacterial properties. The choice of solvent was crucial to optimize electrospinability, productivity, and nanofibers morphology. This study investigated the impact of polymer concentration and electrospinning parameters, such as applied voltage and distance from tip to collector, on nanofibers morphology. To improve the healing process, Ibuprofen (IBU) was encapsulated in PLA nanofibers at a concentration of 5 wt% due to its anti-inflammatory properties. Differential scanning calorimeter (DSC) analysis confirmed the amorphous nature of PLA, while TGA confirmed the presence of IBU and almost complete evaporation of solvent during the electrospinning process. Scanning electron microscopy (SEM) characterization demonstrated that nanofibers fabricated from PLA/IBU solutions electrospun in acetone at concentrations of 10 wt% and 12.5 wt%, using an applied voltage of 40 kV and a tip-to- collector distance of 15 cm, yielded fibers with the most favorable morphological features for the target application. The resulting nanofibers exhibited consistent nanoscale diameters and a smooth, homogeneous surface topology, indicating that these electrospinning parameters represent optimal conditions for achieving high-quality fiber formation. Antimicrobial analyses were conducted to demonstrate the bilayer dressing's effectiveness in inhibiting or eliminating bacterial growth. These tests aimed to assess the potential of this new dressing as a protective barrier against infection, highlighting its relevance for wound care applications.