Connecting in situ cone/jet length in electrospinning to fiber diameter and drug release for the rational design of electrospun drug carriers

Abstract

Towards enabling the rational design of electrospun drug carriers, this study investigated relationships between cone/jet features in electrospinning and operating/solution parameters, fiber diameter or drug release profiles. Cone/jet length were visualized real-time during electrospinning of budesonide (BUD)-loaded poly(caprolactone) (PCL) and poly(D,L-lactide-co-glycolide) (PLGA) solutions. Voltage was varied for BUD-PCL at fixed drug/polymer ratio of 7.4 %, while solution concentration was modulated for BUD-PLGA resulting in drug/polymer ratios of 3.3–4.3 %. In both the BUD-PCL and BUD-PLGA systems, cone length and fiber diameter shared a strong linear relationship (R2 = 0.99, 0.98 respectively). PCL meshes exhibited bi-phasic release profiles, releasing ∼ 95 % BUD over 7 days regardless of fiber diameter, while PLGA meshes exhibited diameter-dependent controlled release. Despite the inconsistent relationship between fiber diameter and release, straight jet length in electrospinning was well-correlated with the Korsmeyer-Peppas parameter for BUD-PCL and the zero-order release parameter for BUD-PLGA (R2 = 0.71, 0.94 respectively). This approach of cone/jet visualization can reduce trial–error experiments and circumvent the cumbersome optimization of several electrospinning parameters for the design of drug-loaded electrospun meshes.