On the Nanomechanical and Viscoelastic Properties of Coatings Made of Recombinant Sea Star Adhesive Proteins

Mathilde Lefevre,Elise Hennebert,Thomas De Muijlder,Thi Quynh Tran,Philippe Leclère,Patrick Flammang,Bede Pittenger

doi:10.3389/fmech.2021.667491

Abstract

To attach to surfaces in the sea, sea stars produce proteinaceous adhesive secretions. Sfp1 is a major constituent of this adhesive, where it is present in the form of four subunits (named Sfp1α to δ) displaying specific protein-, carbohydrate- and metal-binding domains. Recently, two recombinant proteins inspired from Sfp1 have been produced: one corresponding to the C-terminal part of Sfp1β and the other to the full-length Sfp1δ. Adsorption ability tests showed that both recombinant proteins were able to adsorb and to form coatings on different surfaces in artificial seawater as well as in Tris buffer supplemented with NaCl or CaCl2. In this study, we used Atomic Force Microscopy (AFM) to characterize the nanomechanical properties of these coatings with an emphasis on functional characteristics such as adhesive properties and modulus of elasticity. We used AFM techniques which are the most appropriate to characterize the coating microstructure combined with the mapping of its nanomechanical properties.

Highlights

Nowadays, adhesion in wet environments is a crucial economic and medical concern (Almeida et al, 2020)
Glues inspired by adhesive secretions produced by marine organisms are increasingly being studied to replace currently available surgical adhesives and sealants which pose toxicity issues, or which cannot be used in areas continuously bathed with body fluids (Duarte et al, 2012; Annabi et al, 2014)
DOPA (3,4-dihydroxy-L-phenylalanine), which is formed by the posttranslational modification of tyrosine, is the key component of mussel glue, by displaying important interfacial adhesive and bulk cohesive roles (Heinzmann et al, 2016)

Summary

Introduction

Adhesion in wet environments is a crucial economic and medical concern (Almeida et al, 2020) In this context, glues inspired by adhesive secretions produced by marine organisms are increasingly being studied to replace currently available surgical adhesives and sealants which pose toxicity issues (e.g., cyanoacrylate or formaldehyde-based glues), or which cannot be used in areas continuously bathed with body fluids (e.g., fibrin) (Duarte et al, 2012; Annabi et al, 2014). Glues inspired by adhesive secretions produced by marine organisms are increasingly being studied to replace currently available surgical adhesives and sealants which pose toxicity issues (e.g., cyanoacrylate or formaldehyde-based glues), or which cannot be used in areas continuously bathed with body fluids (e.g., fibrin) (Duarte et al, 2012; Annabi et al, 2014) The prerequisite of such applications is the complete molecular and functional characterization of these protein-based marine glues.

Methods

Results

Conclusion