Antibacterial Gel Coatings Inspired by the Cryptic Function of a Mussel Byssal Peptide

Abstract

the mechanism by which the Nepenthes pitcher plant traps its insect prey inspired the design of slippery, self-healing liquid-infused porous surfaces. [1] Melanin, pigments responsible for a host of functions in humans inspired the design of polymeric peptide pigments, [2] and nacre from mollusk shells inspired the design of impact-resistant transparent materials. [3] Over the last several decades, the remarkable adhesive properties of marine mussels have inspired the design of many synthetic underwater adhesives. [4] Close inspection of the molecular machinery responsible for mussel adhesion suggests an additional cryptic function that can be exploited in materials design.Mussels can strongly attach to any organic or inorganic surface in a wet, saline environment, by secreting several byssal proteins that form an adhesive plaque on the surface (Figure 1A). The mussel foot protein-5 (Mfp-5), an interfacial protein distributed along the byssus-substrate interface, is known to be strongly adhesive. [4,5] The primary sequence of Mfp-5 contains a high content of both lysine as well as non-coded 3,4 dihydroxy-l-phenylalanine (DOPA) amino acids. [5,6] It is well known that the reduced catechol form of DOPA is mainly responsible for surface adhesion by participating in various physical interactions with substrates including metal complexation, π-π stacking and hydrogen bonding. [4,[6][7][8][9][10] Lysine can play a synergistic role in adhesion, for example, by evicting hydrated cations from mineral surfaces to provide dry patches for DOPA binding. [8] The oxidized quinone form of DOPA plays an important role in material cohesion undergoing free-radical aryl-aryl couplings and Schiff-base as well as Michael-type reactions with nucleophilic residues such as lysine. [11] Although, the adhesive and cohesive nature of mussel proteins like Mfp-5 have long served to inspire the design of materials embodying these properties, [4,9,[12][13][14][15] their characteristic amino acid compositions suggest that they might also serve to inspire an unrelated material function not yet associated with this class of mussel protein.The high lysine content of Mfp-5 is reminiscent of the high occurrence of this residue in antimicrobial peptides, which impart their action by disrupting bacterial membranes. [16,17] Although the adhesive and cohesive nature of mussel byssal proteins have long served to inspire the design of materials embodying these properties, their characteristic amino acid compositions suggest that they might also serve to inspire an unrelated material function not yet associated with this class of protein. Herein, it is demonstrated that a peptide derived from mussel foot protein-5, a key protein in mussel adhesion, displays antibacterial properties, a yet unreported activity. This cryptic function serves as inspiration for the design of a new class of peptidebased antibacterial adhesive hydrogels prepared via self-assembly, which are active against drug-resistant Gram-positive bacteria. The gels exert two mechanisms of acti...

In situ self-assembly of polydopamine inside injectable hydrogels: antibacterial activity and photothermal therapy for superbug-infected wound healing

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“…Interestingly, the antibacterial rate against the gram negative bacteria was over 80% after 6 h of treatment while the one against B. subtilis is below 60%, which was different from the current perception of high antibacterial activity against gram-positive bacteria. 25,46 In consequence, excellent antibacterial activity could be realized by controlling the self-assembly degree and treatment time.…”

Peptide hydrogels for affinity‐controlled release of therapeutic cargo: Current and potential strategies

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EGCG-crosslinked carboxymethyl chitosan-based hydrogels with inherent desired functions for full-thickness skin wound healing

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