Antibacterial and Antibiofilm Surfaces through Polydopamine-Assisted Immobilization of Lysostaphin as an Antibacterial Enzyme

Abstract

Antibiotic resistance and the colonization of bacteria on surfaces, often as biofilms, prolong hospitalization periods, increase mortality, and are thus major concerns for health care providers. There is an urgent need for antimicrobial and antibiofilm surface treatments that are permanent, can eradicate both biofilms and planktonic pathogens over long periods of time, and do not select for resistant strains. In this study, we have demonstrated a simple, robust, and biocompatible method that utilizes the adhesive property of polydopamine (PDA) to covalently attach the antimicrobial enzyme lysostaphin (Lst) to a variety of surfaces to generate antibacterial and antibiofilm interfaces. The immobilization of the recombinant Lst onto PDA-coated surfaces was carried out under physiological conditions, most probably through the C-terminal His6-tag fragment of the enzyme, minimizing the losses of bioagent activity. The modified surfaces were extensively characterized by X-ray photoelectron spectroscopy and peak force quantitative nanomechanical mapping (PeakForce QNM) AFM-based method, and the presence of Lst on the surfaces was further confirmed immunochemically using anti-Lst antibody. We also found that, in contrast to the physically adsorbed Lst, the covalently attached Lst does not leach from the surfaces and maintains its endopeptidase activity to degrade the staphylococcal cell wall, avoiding most intracellular bacterial resistance mechanisms. Moreover, the Lst-coated surfaces kill hospital strains of Staphylococcus aureus in less than 15 min and prevent biofilm formation. This immobilization method should be applicable also to other proteins and enzymes that are recombinantly expressed to include the His6-tag fragment.

Advanced strategies for combating bacterial biofilms

“…Lysostaphin (LS) is a Staphylococcus simulans metalloendopeptidase that can be served as an antimicrobial against S. aureus (Landini, Antoniani, Burgess, & Nijland, 2010). LS is an antibacterial enzyme that is specifically capable of cleaving the cross-linking pentaglycine (Yeroslavsky, Girshevitz, Foster-Frey, Donovan, & Rahimipour, 2015).…”

Microwave‐Accelerated Rapid, Chemical Oxidant‐Free, Material‐Independent Surface Chemistry of Poly(dopamine)

“…[ 2 ] For instance, pDA and other catecholamine derivatives have been applied to dye-sensitized solar cells, [ 3 ] biomineralization, [ 4 ] immunosensors, [ 5 ] ring-opening polymerization, [ 6 ] Li-ion battery separators, [ 7 ] water detoxifi cation, [ 8 ] and antibacterial/biofi lm applications. [ 9 ] In particular, the pDA coating is a convenient tool to functionalize surfaces with superwettability. [ 10 ] For example, pDA is the fi rst aqueous-based coating method to functionalize superhydrophobic surfaces.…”

Versatile Surface Modification Using Polydopamine and Related Polycatecholamines: Chemistry, Structure, and Applications

“…The reactivity of polydopamine surfaces toward these nucleophiles is dependent on the catechol/quinone equilibrium and consequently alkaline pH accelerates conjugation reactions . In this instance, the p K a of the nucleophile is also relevant as it is deprotonated nucleophiles that react and so for neutral pH imidazole (p K a ≈ 6) reacts better than a primary amine (p K a ≈ 10), but this is reversed at higher pH . The coupling between nucleophiles and polydopamine surfaces have been used for the attachment of small molecules, synthetic polymers, biomolecules, and the construction of metal–organic frameworks …”