Effect of Solution Composition Variables on Electrospun Alginate Nanofibers: Response Surface Analysis

Abstract

Alginate is a promising biocompatible and biodegradable polymer for production of nanofibers for drug delivery and tissue engineering. However, alginate is difficult to electrospin due to its polyelectrolyte nature. The aim was to improve the ‘electrospinability’ of alginate with addition of exceptionally high molecular weight poly(ethylene oxide) (PEO) as a co-polymer. The compositions of the polymer-blend solutions for electrospinning were varied for PEO molecular weight, total (alginate plus PEO) polymer concentration, and PEO proportion in the dry alginate–PEO polymer mix used. These were tested for rheology (viscosity, complex viscosity, storage and loss moduli) and conductivity, and the electrospun nanofibers were characterized by scanning electron microscopy. One-parameter-at-a-time approach and response surface methodology (RSM) were used to optimize the polymer-blend solution composition to obtain defined nanofibers. Both approaches revealed that the major influence on nanofiber formation and diameter were total polymer concentration and PEO proportion. These polymer-blend solutions of appropriate conductivity and viscosity enabled fine-tuning of nanofiber diameter. PEO molecular weight of 2–4 million Da greatly improved the electrospinnability of alginate, producing nanofibers with >85% alginate. This study shows that RSM can be used to design nanofibers with optimal alginate and co-polymer contents to provide efficient scaffold material for regenerative medicine.

High Efficiency Fabrication of Chitosan Composite Nanofibers with Uniform Morphology via Centrifugal Spinning

“…Currently, electrospinning is the most popular method to produce nanofibers with uniform diameter distribution [23,24,25,26]. However, electrospinning still has some serious disadvantages, such as low spinning rate (less than 1 mL/h) and high energy consumption [27,28].…”

Encapsulating bacteria in alginate-based electrospun nanofibers

“…Fiber formation, diameter, and morphology depend on both solution properties, like concentration, density, conductivity, and surface tension, as well as experimental parameters, including solution flow rate, tip-tocollector distance, and applied voltage. [32][33][34][35][36][37][38][39][40] The high surface area to volume ratios and high porosities of these nanofiber mats make them suitable for many biomedical applications, including protective clothing, 41 wound dressing, 32,42 vascular grafts, 43 and drug delivery. 31 Previously, it has been demonstrated that electrospinning can be used to encapsulate a wide variety of viable bacteria, including Gram-negative and Grampositive cells into dry nanofiber mats.…”

Role of Electrospinning Parameters on Poly(Lactic-co-Glycolic Acid) and Poly(Caprolactone-co-Glycolic acid) Membranes

“…Plasticity contributes to nanofiber formation, and elasticity is critical in the stage of jet formation and elongation, preventing the jet from breaking up. A higher G ′ results consequently in a beadless nanofiber structure [ 39 ]. In this case, both co-polymer solutions show a higher storage modulus than the loss one, it being greater for PCLGA.…”