Cyclodextrin fibers via polymer-free electrospinning

Abstract

Cyclodextrins (CDs) are intriguing amphiphilic molecules that consist of a hydrophilic outer structure and a hydrophobic core with the ability to act as hosts for both nonpolar and polar guests. Electrospinning is a facile yet effective method for producing non-woven mats of fibers with high aspect ratios. Cyclodextrin fibers would leverage the distinctive properties of these molecules with the unique properties of nanofibers. We report the fabrication of submicron hydroxypropyl-β-cyclodextrin (HPβCD) fibers from highly concentrated aqueous solutions by electrospinning without the addition of a carrier polymer. We focus on exploring solution properties that make fiber formation possible contrary to the widely accepted premise that molecular entanglement of macromolecules is required for electrospinning. The ability to electrospin these solutions is attributed to hydrogen-bonded aggregation between HPβCD molecules at high concentrations, as evidenced from an exponential increase in zero-shear viscosity and bound water as a function of concentration, as well as disruption of fiber formation upon addition of urea to the system.