Effect of entrapped α-tocopherol on mucoadhesivity and evaluation of the release, degradation, and swelling characteristics of zein–chitosan composite electrospun fibers

Abstract

A gastro-mucoadhesive matrix of ultrafine fibers was formed from composite polymers of zein, poly(ethylene oxide), and chitosan at a ratio of 87.5/10/2.5 via electrospinning. Alpha-tocopherol (α-TOC), a hydrophobic compound, was embedded at 20wt% into the fiber matrix to investigate its effects on fiber morphology and mucoadhesivity. α-TOC release characteristics were examined in simulated gastric fluid (SGF) at pH 1.2 with pepsin and SGF at pH 2 without pepsin at 37±0.5°C. Gastro-mucoadhesivity was tested in porcine gastric mucosa. Fiber morphology was characterized by scanning electron microscopy (SEM). α-TOC did not affect fiber morphology, but significantly enhanced mucoadhesivity (p<0.05). α-TOC release in SGF at pH 1.2 with pepsin was triggered by erosion, and α-TOC release in SGF at pH 2 without pepsin was triggered by swelling, and driven by diffusion. SEM micrographs revealed that the fibers lost their fibrous structure and later fused, minimizing the fibrous film release surface area.