The Effect of Solvent Vapor Annealing on Drug-Loaded Electrospun Polymer Fibers

Abstract

Electrospinning has emerged as a powerful strategy to develop controlled release drug delivery systems but the effects of post-fabrication solvent vapor annealing on drug-loaded electrospun fibers have not been explored to date. In this work, electrospun poly(ε-caprolactone) (PCL) fibers loaded with the hydrophobic small-molecule spironolactone (SPL) were explored. Immediately after fabrication, the fibers are smooth and cylindrical. However, during storage the PCL crystallinity in the fibers is observed to increase, demonstrating a lack of stability. When freshly-prepared fibers are annealed with acetone vapor, the amorphous PCL chains recrystallize, resulting in the fiber surfaces becoming wrinkled and yielding shish-kebab like structures. This effect does not arise after the fibers have been aged. SPL is found to be amorphously dispersed in the PCL matrix both immediately after electrospinning and after annealing. In vitro dissolution studies revealed that while the fresh fibers show a rapid burst of SPL release, after annealing more extended release profiles are observed. Both the rate and extent of release can be varied through changing the annealing time. Further, the annealed formulations are shown to be stable upon storage.

A simple route to functionalising electrospun polymer scaffolds with surface biomolecules

“…PCL, a semi-crystalline polymer widely used in the manufacturing of surgical sutures, drug delivery systems and tissue engineering scaffolds, was selected for this study. It is biocompatible and biodegrades through hydrolysis over a time period ranging from several months to years, depending on the molecular weight (Chiu et al, 2020;Labet and Thielemans, 2009), making it an attractive polymer for an implantable formulation. Moreover, it is not soluble in methanol or ethanol and can be safely functionalised with a methanolic PFPA-NHS solution and pre-sterilised in EtOH for biological applications.…”

“…Representative XPS survey spectra are presented in Figure S5. For untreated samples, the survey spectra identified elements corresponding to the PCL structure (carbon and oxygen) (Chiu et al, 2020), while in PFPA-NHS-treated samples additional fluorine and nitrogen signals were detected. The XPS survey analysis allowed for the quantification of surface elements (Table S1).…”

Application of electrospinning technique in development of intelligent food packaging: A short review of recent trends

“…More detailed information regarding the function of electrospinning can be found in studies of Deshwal and Panjagari (2018), Rostami, Yousefi, Khezerlou, Aman Mohammadi, and Jafari (2019), Kotomin, Kulichikhin, and Skvortsov (2018), and Chiu et al. (2020).…”

Electrospun nanofibers: A nanotechnological approach for drug delivery and dissolution optimization in poorly water-soluble drugs

“…On the other hand, the fine filament travels following a chaotic trajectory in a whip-like motion, known as bending instability. When it reaches the collector the continuous filament accumulates or deposits to form the nanofiber [56][57][58][59][60].…”