Design of Cinnamaldehyde- and Gentamicin-Loaded Double-Layer Corneal Nanofiber Patches with Antibiofilm and Antimicrobial Effects

In this study, two-layer poly(vinyl alcohol)/gelatin(PVA/GEL)nanofiber patches containing cinnamaldehyde (CA) in the first layerand gentamicin (GEN) in the second layer were produced by the electrospinningmethod. The morphology, chemical structures, and thermal temperaturesof the produced pure (PVA/GEL), CA-loaded (PVA/GEL/CA), GEN-loaded(PVA/GEL/GEN), and combined drug-loaded (PVA/GEL/CA/GEN) nanofiberpatches were determined by scanning electron microscopy (SEM), Fouriertransform infrared spectroscopy, and differential scanning calorimetry,respectively. Their mechanical properties, swelling and degradationbehavior, and drug release kinetics were investigated. SEM imagesshowed that both drug-free and drug-loaded nanofiber patches possesssmooth and monodisperse structures, and nanofiber size increase occurredas the amount of drug increased. The tensile test results showed thatthe mechanical strength decreased as the drug was loaded. Accordingto the drug release results, CA release ended at the 96th hour, whileGEN release continued until the 264th hour. The antibacterial andantibiofilm activities of PVA/GEL, PVA/GEL/CA, PVA/GEL/GEN, and PVA/GEL/CA/GENnanofiber patches against Pseudomonas aeruginosa and Staphylococcus aureus were evaluated.Results showed that PVA/GEL/GEN and PVA/GEL/CA/GEN nanofiber patcheshave excellent antibacterial and antibiofilm activities. Moreover,all materials were biocompatible, with no cytotoxic effects in themammalian cell model for 8 days. PVA/GEL/GEN nanofiber patches werethe most promising material for a high cell survival ratio, whichwas confirmed by SEM images. This research aims to develop an alternativemethod to stop and treat the rapid progression of bacterial keratitis.