Multiphase Adhesive Coacervates Inspired by the Sandcastle Worm

Abstract

Water-borne, underwater adhesives were created by complex coacervation of synthetic copolyelectrolytes that mimic the proteins of the natural underwater adhesive of the sandcastle worm. To increases bond strengths, a second polymer network was created within crosslinked coacervate network by entrapping polyethylene glycol diacrylate (PEG-dA) monomers in the coacervate phase. Simultaneous polymerization of PEG-dA and crosslinking of the coacervate network resulted in maximum shear bond strengths of ∼ 1.2 MPa. Approximately 40% of the entrapped PEG-dA polymerized based on attenuated total reflectance-Fourier transform infrared spectroscopy. The monomer-filled coacervate had complex flow behavior, thickening at low shear rates, then thinning suddenly with a 16-fold drop in viscosity at shear rates near 6 s-1. The microscale structure of the complex coacervates resembled a three-dimensional porous network of interconnected tubules. The sharp shear thinning behavior is conceptualized as a structural reorganization between the interspersed phases of the complex coacervate. The bond strength and complex fluid behavior of the monomer-filled coacervates have important implications for medical applications of the adhesives.

Mussel adhesion-employed water-immiscible fluid bioadhesive for urinary fistula sealing

“…This is a distinguishable feature of WIMBA due to its superior waterimmiscibility. Even though several studies measured underwater adhesive strengths of their developed adhesives after curing in the presence of water, the adhesives were just applied in dry or wet conditions [18,35,36]. Using porcine skin tissue as a test adherend, Fig.…”

“…These features satisfy the requirements of underwater adhesion. Actually, a coacervated underwater adhesive, which is composed of synthetic polymers inspired by sandcastle worm's protein adhesive, was developed and exhibited underwater adhesion ability [18]. The other solution for underwater adhesion can get a hint from a marine organism, mussel.…”

Silk tape nanostructure and silk gland anatomy of trichoptera

“…Bicontinuous phases have been observed in synthetic complex coacervates that also exhibit discontinuous flow behavior with sudden drops in viscosity at critical shear rates. 35,36 The ''bulbous prominence" of the caddisfly larval silk gland, occurring at the transition from the gland's middle storage region to the anterior lumen, appeared to be the critical region where silk fiber precursors were reorganized into insoluble fibers. In Rhyacophila, the bulbous anatomy was especially pronounced (Figures 10A and 10B).…”

Linear viscoelasticity of complex coacervates

“…The self-assembly of these materials is driven by entropy, where the initial electrostatic attraction between oppositely-charged macro-ions results in the release of small, bound counter-ions and the restructuring of water molecules [1][2][3][4]. Complex coacervates have a long history of use in the food [5][6][7][8][9][10][11][12][13] and personal care [14,15] industries, and have found increasing utility as a platform for drug and gene delivery [1][2][3][4], as well as underwater adhesives [5][6][7][8][9][10][11][12][13][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62]. Coacervation has also recently been implicated in the formation of various biological assemblies [1,[14][15][16]55,…”