The significance of electrospinning as a method to create fibrous scaffolds for biomedical engineering and drug delivery applications

Core/shell poly(ethylene oxide)/Eudragit fibers for site-specific release

Electrospinning was used to prepare core/shell fibers containing the active pharmaceutical ingredients indomethacin (IMC) or mebeverine hydrochloride (MB-HCl). The shell of the fibers was fabricated from the pH sensitive Eudragit S100 polymer, while the drug-loaded core was based on the mucoadhesive poly(ethylene oxide) (PEO). Three different drug loadings (from 9 to 23% (w/w) of the core mass) were prepared, and for MB-HCl two different molecular weights of PEO were explored. The resultant fibers generally comprise smooth cylinders, although in some cases defects such as surface particles or flattened or merged fibers were visible. Transmission electron microscopy showed all the systems to have clear core and shell compartments. The drugs are present in the amorphous physical form in the fibers. Dissolution tests found that the fibers can effectively prevent release in acidic conditions representative of the stomach, particularly for the acidic indomethacin. After transfer to a pH 7.4 medium, sustained release over between 6 and 22h is observed. Given the mucoadhesive nature of the PEO core, after dissolution of the shell the fibers will be able to adhere to the walls of the intestinal tract and give sustained local drug release. This renders them promising for the treatment of conditions such as irritable bowel disease and colon cancer.

Composite Electrospun Scaffold Derived from Recombinant Fibroin of Weaver Ant (Oecophylla smaragdina) as Cell-Substratum

Unlike silkworm (Bombyx mori) fibroin (SF), weaver ant (Oecophylla smaragdina) fibroin (WAF) is much less studied. Due to differences in amino acid composition and protein structure, this work aimed to produce the recombinant WAF protein, designated as WAF1, and investigated on its potential application as a biomaterial for producing a cell-substratum. The composite electrospun scaffolds derived from poly(vinyl alcohol) (PVA), WAF1, and extracted SF were produced by electrospinning. SEM images revealed non-woven and smooth fibers of PVA, PVA-WAF1, and PVA-SF scaffolds with the average diameters of 204.1 ± 59.9, 206.5 ± 71.5, and 238.4 ± 77.9 nm, respectively. ATR-FTIR spectra indicated characteristic absorption peaks related to the chemical structure of PVA and protein. The PVA-WAF1 scaffold demonstrated a higher water uptake, a slightly higher rate of degradation, and a similar low cytotoxicity as compared with the PVA-SF scaffold. Although the adhesion and proliferation of cells on the PVA-WAF1 scaffold were lower than those on the PVA-SF scaffold, it showed significantly greater values of adhering and proliferating cells than the PVA scaffold. The results of this work suggested that WAF1 could be used as a biomaterial for producing a cell-substratum that supports cell adhesion and growth.

Emulsion-based systems for fabrication of electrospun nanofibers: food, pharmaceutical and biomedical applications

Encapsulation of bioactive materials and drugs using the emulsion electrospinning method.