Electrospinnable, Neutral Coacervates for Facile Preparation of Solid Phenolic Bioadhesives

Abstract

Liquid–liquid phase separation in an aqueous polymer solution is a unique physicochemical phenomenon, and the material present in the dense bottom layer is called a coacervate. A partial degree of water exclusion during coacervate formation often results in adhesive properties. The high viscosity makes coacervates incompatible with electrospinning processes. Coacervates can be electrospinnable only when the viscosity level of coacervates is adjusted. Electrospinning of coacervates results in a liquid-to-solid phase transition, addressing a long-term stability issue of coacervates. The preserved electrospun membranes can always be reconverted to a coacervate state by dissolution. Herein, we fabricate a spinnable coacervate solution using cosolvents. For neutral, hydrogen bond-dominated coacervates, such as those composed of poly­(vinyl alcohol) (PVA) and phenolic tannic acid (TA), the use of a polar cosolvent system such as methanol–water results in an electrospinnable coacervate solution. The spun PVA–TA porous mats are a physicochemically stable solid, and the materials are converted back to an adhesive state upon wetting with body fluid. Considering the emerging studies related to coacervate adhesives, this study suggests that electrospinning a coacervate solution can be a strategy to dramatically increase the material stability and functionality.

Hydrogen-Bonding Interaction-Driven Catechin Assembly into Solvent-Free Supramolecular Adhesive with Antidrying and Antifreezing Properties

“…It can also be synthesized using sugar through multistep enzymatic reactions . As an important bioactive molecule, catechin (CA) can exert the effects of antisepsis, antioxidation, anticancer, and hemostasis. − Very recently, analogous polyphenol compounds have been used to prepare multiple underwater medical adhesives. − Wherein, phenolic hydroxyl groups were regarded as donors of hydrogen bond to interact with other components containing hydrogen-bond acceptors. Interestingly, they have not yet been considered for the preparation of solvent-free supramolecular adhesives.…”

Multifunctional 3D platforms for rapid hemostasis and wound healing: Structural and functional prospects at biointerfaces

“…(B) Blood loss of hemostatic gauzes [ 83 ] . (C) Effect of nanofiber weight on mass and the time of bleeding [ 152 ] . (D) Effects of fiber diameter on mechanical properties [ 91 ] .…”

Tannic-Acid-Enriched Poly(vinyl alcohol) Nanofibrous Membrane as a UV-Shie lding and Antibacterial Face Mask Filter Material

“…Importantly, the electrospun NFMs must be water-resistant to take advantage of the morphology of the nanofibers. For example, Cui et al reported a PVA–TA nanofiber, but the mixing ratio of TA to PVA was only 0.2:1, and Kim et al prepared a PVA NFM containing a large amount of TA, but this was immediately converted to the coacervate state upon contact with water …”

“…For example, Cui et al reported a PVA−TA nanofiber, but the mixing ratio of TA to PVA was only 0.2:1, 20 and Kim et al prepared a PVA NFM containing a large amount of TA, but this was immediately converted to the coacervate state upon contact with water. 21 Herein, we report a NFM-based face mask filter composed of PVA and TA in a weight ratio of 1:0.5. To enable green electrospinning, the formation of strong hydrogen bonds between PVA and TA was partially inhibited using a mixed solvent of water/ethanol, and the resultant solution was homogeneous without any aggregation or precipitation.…”