Mechanically Robust Poly(vinyl alcohol)-Egg White Composite Hydrogel with Enhancing Biocompatibility by Unidirectional Nanopore Dehydration

A simple and green method, unidirectional nanopore dehydration (UND), directly processes 10% poly(vinyl alcohol) (PVA) aqueous solution containing 20% egg white (EW) into a composite hydrogel membrane (PVA-EW). The tensile strength and elongation of the UND-based PVA-EW at 25 °C were 0.91 MPa and 534.17%, respectively, while the two values at 70 °C were increased by 700 and 38%, respectively. The PVA-EW (70 °C) was still dominated by random coils and α-helical structures. The hydroxyl groups of intramolecules and intermolecules of both PVA and EW could be able to combine and form either more hydrogen bonds or stronger hydrogen bonds. PVA-EW is soft and translucent, has good mechanical properties, and has a porous networked structure with pores that have a diameter of 1-10 μm. L-929 mouse fibroblasts were found to be able to adhere, grow, and proliferate well on the hydrogel composite membrane. This novel PVA-EW biomaterial has potential applications in biomaterials especially medical tissue engineering.

An insight on egg white: From most common functional food to biomaterial application

Natural egg white tis widely used as an ingredient in nutritional foods and for food processing. Due to its characteristic foaming, emulsification, adhesion, and gelation, and its heat setting, biocompatibility, and low cost, research into the application and development of egg white in biomaterials, especially medical biomaterials, have been receiving attention. The composition and characteristics of egg white protein, and the physical mixing and chemically cross-linking of egg white with other materials used to make degradable packaging films, bioceramics, bioplastics, biomimetic films, hydrogels, 3D scaffolds, bone regeneration, biopatterning, biosensors, and so forth, are reviewed in detail in this report. The novel egg white-based biomaterials in various forms and applications could be constructed mostly through physical treatments such as ultrasonic wave, ultraviolet, laser and other radiation or high-temperature calcination. Furthermore, the application and prospects for the use of egg white in biomaterials is also discussed.

Adsorption capacity of kelp-like electrospun nanofibers immobilized with bayberry tannin for uranium(vi) extraction from seawater

The extraction of uranium(vi) from seawater is of paramount interest to meet the rapid expansion of global energy needs. A novel gelatin/PVA composite nanofiber band loaded with bayberry tannin (GPNB-BT) was used to extract uranium(vi) from simulated seawater in this study. It was fabricated by electrostatic spinning and crosslinking, and characterized by SEM, EDX, FTIR, and XPS. Batch experiments were carried out to investigate the adsorption of uranium(vi) onto GPNB-BT. Simultaneously, the regeneration-reuse process of the GPNB-BT was determined and illustrated here. The GPNB-BT exhibited excellent adsorption and regeneration performance, and a maximum adsorption capacity of 254.8 mg g-1 toward uranium(vi) was obtained at 298.15 K, pH = 5.5. Further, the regeneration rate for uranium did not decrease significantly after five cycles. Moreover, even at an extremely low initial concentration of 3 μg L-1 in the simulated seawater for 24 h, GPNB-BT showed an ultrahigh adsorption rate of more than 90% and adsorption capacity of 7.2 μg g-1 for uranium. The high density of adjacent phenolic hydroxyl groups and the specific surface area of GPNB-BT improved the adsorption ability of GPNB-BT for uranium. Therefore, the GPNB-BT was shown to have an application prospect for the effective extraction of uranium(vi) from seawater.