Fibrous scaffolds made by co-electrospinning soluble eggshell membrane protein with biodegradable synthetic polymers

Soluble eggshell membrane protein (SEP), isolated from natural eggshell membrane, was co-electrospun with biodegradable synthetic polymers poly(propylene carbonate) (PPC) and poly(lactic acid) (PLA) in various proportions from 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) solutions in order to prepare fibrous scaffolds having simultaneously good mechanical properties and biocompatibility. The fiber morphology was observed by field emission scanning electron microscopy, showing uniform fibers with diameter of 1.2-1.0 and 1.3-0.7 um for PPC/SEP and PLA/SEP blend fibers, respectively. Transmission electron microscopy observation shows that the blend fibers have domain-matrix phase morphology with fiber-like SEP domains in the PPC or PLA matrix, indicating the occurrence of phase separation, although interaction exists between PPC (or PLA) and SEP, as revealed by attenuated total reflectance Fourier transform infrared spectroscopy. The mechanical properties were evaluated by uniaxial tensile tests and showed that both the tensile strength and elongation at break increase with increasing incorporation of PPC (or PLA). The surface composition was investigated by X-ray photoelectron spectroscopy and SEP was found on the fiber surfaces, and as a result the surfaces of the fibrous scaffolds are superhydrophilic. NIH3T3 cell culture tests demonstrate that the PPC/SEP and PLA/SEP blend fibrous scaffolds have a much improved biocompatibility compared to pure PPC or PLA fibrous scaffolds.