Advanced pullulan nanofibers reinforced by cellulose fibrils as drug carriers for salicylic acid

The goal of the current work is to showcase the synthesis of homogeneous pullulan nanofibers that are strengthened by the addition of cellulose nanofibrils (CNF). One of the main difficulties this study faced was determining the ideal water/organic solvent ratio for the electrospinning process, which would allow for the maximum reduction in the amount of organic solvent (DMF or DMSO) needed. The rheological behavior of electrospinning solutions was modulated by varying both, the pullulan concentration and solvent system composition. The amount of CNF in the composition significantly affects the properties of the created nanofibers. When the CNF content increased from 1 % to 5 %, the diameter of the fibers decreases from 284 nm to 90 nm. This is attributed to the enhanced conductivity and surface charge density of the solution jet. The as prepared nanofibres can hold a variety of drugs and can be used to create novel formulations for various biomedical purposes. The nanofibres were tested for salicylic acid incorporation and release. Drug release exhibited zero-order kinetics, suggesting that the concentration remained unaffected by the rate of release. Furthermore, the nanofibres demonstrated remarkable antibacterial activity against both Gram-positive and Gram-negative bacteria.