Natures wonders: mussels extreme adherence in the wet (Introduction)

by David Turell , Wednesday, September 02, 2020, 18:26 (1325 days ago) @ David Turell

The design of mussel adherence is further explored:

https://www.nature.com/articles/s41467-020-17597-4

Abstract:

"The mussel byssus has long been a source of inspiration for the adhesion community. Recently, adhesive synergy between flanking lysine (Lys, K) and 3,4-Dihydroxyphenylalanine (DOPA, Y) residues in the mussel foot proteins (Mfps) has been highlighted. However, the complex topological relationship of DOPA and Lys as well as the interfacial adhesive roles of other amino acids have been understudied. Herein, we study adhesion of Lys and DOPA-containing peptides to organic and inorganic substrates using single-molecule force spectroscopy (SMFS). We show that a modest increase in peptide length, from KY to (KY)3, increases adhesion strength to TiO2. Surprisingly, further increase in peptide length offers no additional benefit. Additionally, comparison of adhesion of dipeptides containing Lys and either DOPA (KY) or phenylalanine (KF) shows that DOPA is stronger and more versatile. We furthermore demonstrate that incorporating a nonadhesive spacer between (KY) repeats can mimic the hidden length in the Mfp and act as an effective strategy to dissipate energy.

Introduction:

"One of the great challenges faced by man-made adhesives is binding in the presence of water, salts, and surface contaminants1. Marine mussels, on the other hand, have perfected the art of adhering tenaciously to a variety of surfaces in wet conditions. The strong attachment of mussels is mediated by the byssus, a proteinaceous holdfast that is formed by secretion and solidification of specialized adhesive proteins. A unique feature of these interfacial proteins is the presence of large amounts of post-translationally modified amino acid 3,4-dihydroxyphenylalanine (DOPA), a catechol-containing residue that is believed to be a major contributor to wet adhesion. Bioinspired design principles based on mimicking these interfacial proteins have been employed extensively and resulted in a variety of catechol functionalized polymers for bio-compatible adhesives, self-healing hydrogels, and surgical wound closure materials.

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"The findings in this work can provide a solid foundation to tailor properties and further guide the deliberate design and synthesis of bioinspired wet adhesives."

Comment: The above sentence is a referral to stealing nature's secrets to help us with biomimetic products. Nature is much smarter than we are. The key thought here is mussels have worked out a worthwhile lifestyle adhering to ships. The obvious issue is how did they evolve these adhesive proteins in the first place? How did they find the first good adhesive so teh process could start in place? Only help from a designer is reasonable.