A precise look at electrospinning parameters in fabricating the polymeric nanofibers: a review on synthetic and natural polymers

Polymeric nanofibers have been used in various applications, including drug delivery, wound dressing, tissue engineering, biosensors, and implants. A wide range of cargoes such as drugs, metal nanoparticles, proteins, cells, and herbal extracts could be loaded into these systems. Among all the different methods of fabricating fibers, the electrospinning technique has got a significant interest. Fibers could be generated from synthetic and natural polymers and even the mixture of these polymers using simple, co-axial, or side-by-side spinneret. Polymers should be either dissolved or dispersed in their solvents, making solutions or emulsions, respectively. Electrospinning processing conditions, including solution parameters (polymer molecular weight, polymer concentration, and solvent) and equipment parameters (feeding rate, applied voltage, needle-to-collector distance, and speed of collector in rotating collectors) could influence diameter, morphology, or orientation of nanofibers.

This article highlights synthetic polymers (such as polyvinylpyrrolidone, polyvinyl alcohol, polyurethane, polyethylene oxide, poly e-caprolactone, polylactic acid, and poly(lactic-co-glycolic acid)) and natural polymers (such as gelatin, chitosan, collagen, silk fibroin, and zein) considering their electrospinning process variables. Also, the electrospinning process and formulation parameters are summarized in the most recent studies.

Choosing proper electrospinning parameters is crucial in fabricating nanofibers. This article summarizes the most important electrospinning factors, including the active ingredient, molecular weight and concentration of applied polymers, solvent, voltage, etc. This article can provide a means to quickly assess the preparation conditions of nanofibers and guide formulators to choose the most suitable electrospinning conditions for nanofiber preparation.