Electrospun nanofibers based on biocompatible polymers such as chitosan and poly(lactic acid) (PLA) are promising materials for biomedical applications, especially for wound healing and drug delivery. The incorporation of antibiotics into nanofibers can increase their therapeutic potential through local infection control. However, the addition of antibiotics can affect the morphological properties of the fibers, which may impair their performance.

In this study, nanofibers were produced by the electrospinning technique using a mixture of 22% poly(lactic acid) (PLA) in chloroform and 0.02% chitosan in 90% acetic acid at a volume ratio of 1:1. The antibiotics ciprofloxacin and gentamicin were added to the polymer solution at a concentration of 0.1%. The morphology and fiber diameters were analyzed by scanning electron microscopy (SEM). Pure chitosan/PLA nanofibers showed a uniform morphology with an average fiber diameter of 511.39 ± 150.19 nm. The addition of ciprofloxacin increased the average diameter to 675.35 ± 142.30 nm, while gentamicin increased it to 596.60 ± 164.91 nm. SEM images showed morphological differences between the samples, with ciprofloxacin causing thicker and more heterogeneous fibers compared to gentamicin. The increase in fiber diameter after the addition of the antibiotic is related to changes in solution viscosity and conductivity caused by interactions between polymer and antibiotic, e.g., hydrogen bonding. Ciprofloxacin and gentamicin differ in their molecular interactions with the chitosan/PLA matrix, which explains the differences in fiber morphology and diameter. These results are consistent with previous studies showing that impregnation with antibiotics changes the properties of the electrospinning solution and the fiber structure. The incorporation of antibiotics significantly affects the morphological properties of chitosan/PLA nanofibers. Ciprofloxacin causes a significant increase in fiber diameter compared to pure nanofibers. Understanding these effects is essential for the optimization of nanofiber scaffolds for biomedical applications, especially for the controlled delivery of antibiotics.