Effect of coagulation bath parameters on the morphology and absorption behavior of a skin–core filament based on biomedical polyurethane and native silk fibroin microparticles

Abstract

This study investigates the effect of the constituents and temperature of a coagulation bath on the morphology and water absorption behavior of a skin–core filament, which has potential application in the field of controlled drug release, based on biomedical polyurethane (BPU) and native silk fibroin microparticles (NSFPs). BPU solution and BPU/NSFP blend solution were extruded from the cortex and core channel of a coaxial double injector into a coagulation bath with different constituents and at different temperatures to form filaments. Scanning electron microscopy analysis of the skin–core filament prepared by wet-spinning revealed that the addition of ethanol decreased the exchange speed between the solvent and non-solvent and led to the formation of micropores on the surface. Meanwhile, the interface between the cortex and core became pronounced and the water absorption capability of the filament decreased with increasing ethanol concentration in the coagulation bath. The high temperature of the coagulation bath also improved the exchange speed between the solvent and non-solvent; however, its effect on the morphology of the filament was weak. Thus, a skin–core filament with different morphologies and water absorption behaviors was fabricated by controlling the constituents and temperature of the coagulation bath during the wet-spinning process. This skin–core filament has potential applications in controlled drug release.

Fabrication of a High-Toughness Polyurethane/Fibroin Composite without Interfacial Treatment and Its Toughening Mechanism

“…Due to the advantages of superfine technology, fibroin powder is currently being explored as a green alternative for preparing regenerated materials. Typically, fibroin powder is blended with a synthetic polymer, especially polyurethane, to meet the diversity of demand for functional materials owing to their improved mechanical properties. , Different superfine fibroin powder/polyurethane-based materials have been demonstrated in our previous studies (Figure ), i.e., breathable textile coatings, bionic fibers, efficient dye sorbents for removing dyes from textile effluents, drug delivery for controlling heparin release, and small-diameter vascular tubular materials with high biocompatibility to blood both in vivo and in vitro . − However, despite the remarkable potential and diversity of fibroin powder blends, their applications have been limited by challenges including poor mechanical properties and brittleness associated with a high concentration of superfine fibroin powders. Recently, researchers have tried to improve the mechanical properties of silk fibroin blends by plasma treatment, but unfortunately, the results are not satisfactory .…”

Enhanced mechanical performance of biocompatible silk fibroin films through mesoscopic construction of hierarchical structures

“…8,9 Although SF exhibits great plasticity, a film material made entirely of SF exhibits a high Young's modulus and low stretchability, which makes it difficult to be applied to the substrate for functionalized flexible materials and limits its applicability. Numerous studies have modified the physical and mechanical properties of silk films by blending them with a second-phase material, including glycerol, 10 wool keratin, 8,11,12 gelatin, 13 CaCl 2 , 14 polyurethane (PU), 15 Ag nanoclusters, 16 chitosan, 17,18 etc. In many cases, the mechanical property of the composite silk film has excellent ductility; however, maintaining a certain film strength remains challenging.…”