Broad-Spectrum Anti-Adhesive Coating Based on an Extracellular Polymer from a Marine Cyanobacterium

Abstract

Medical device-associated infections are a major health threat, representing about half of all hospital-acquired infections. Current strategies to prevent this problem based on device coatings with antimicrobial compounds (antibiotics or antiseptics) have proven to be insufficient, often toxic, and even promoting bacterial resistance. Herein, we report the development of an infection-preventive coating (CyanoCoating) produced with an extracellular polymer released by the marine cyanobacterium Cyanothece sp. CCY 0110. CyanoCoating was prepared by spin-coating and its bacterial anti-adhesive efficiency was evaluated against relevant etiological agents (Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa and Escherichia coli) and platelets, both in the presence or absence of human plasma proteins. CyanoCoating cytotoxicity was assessed using the L929 fibroblasts cell line. CyanoCoating exhibited a smooth topography, low thickness and high hydrophilic properties with mild negative charge. The non-cytotoxic CyanoCoating prevented adhesion of all the bacteria tested (≤80%) and platelets (<87%), without inducing platelet activation (even in the presence of plasma proteins). The significant reduction in protein adsorption (<77%) confirmed its anti-adhesive properties. The development of this anti-adhesive coating is an important step towards the establishment of a new technological platform capable of preventing medical device-associated infections, without inducing thrombus formation in blood-contacting applications.

Natural Cyanobacterial Polymer-Based Coating as a Preventive Strategy to Avoid Catheter-Associated Urinary Tract Infections

“…CyanoCoating was previously characterized in terms of thickness and wettability [ 20 ]. However, since surface topography is known to impact biofilm development, this parameter was evaluated by atomic force microscopy (AFM).…”

“…However, since surface topography is known to impact biofilm development, this parameter was evaluated by atomic force microscopy (AFM). CyanoCoating and medical grade polyurethane (PU) were covalently bound through a polydopamine (pDA) layer to gold (Au) substrates, as previously described [ 20 ]. The deposition of either the pDA + CyanoCoating or the control pDA + PU increased significantly surface roughness of Au substrates, as depicted in Figure 1 A. CyanoCoating exhibited a smoother surface in comparison with PU, as demonstrated by the decrease of the average roughness (Ra) ( Figure 1 A 1 ) and the root mean square roughness (Rq) ( Figure 1 A 2 ).…”

“…As the anti-adhesive performance of CyanoCoating was previously evaluated against Escherichia coli and Pseudomonas aeruginosa [ 20 ], herein, we focused on other relevant uropathogens for catheter-associated urinary tract infections (CAUTIs): Proteus mirabilis , Klebsiella pneumoniae , methicillin resistant Staphylococcus aureus (MRSA), and Candida albicans [ 22 ], according to ISO 22196:2007 [ 23 ]. Overall, the results obtained ( Figure 2 and Figure S1 ) showed that microbial adhesion to CyanoCoating was significantly lower than the adhesion to medical grade PU, ranging from 68 ± 28% ( P. mirabilis ) to 95 ± 48% ( K. pneumoniae ).…”

“…Polysaccharides from marine sources, such as alginate, ulvan, agarose, and carrageenans have also been reported as possible alternatives [ 16 , 18 , 19 ]. Previously, Costa et al [ 20 ] developed CyanoCoating, a coating based on a well-characterized extracellular polymer produced by a marine cyanobacterium [ 21 ]. These authors demonstrated that CyanoCoating has anti-adhesive properties against S. aureus , S. epidermidis , P. aeruginosa , and E. coli , and is biocompatible, having the potential to be applied to a wide range of medical devices, including blood contacting materials [ 20 ].…”

Cyanoflan: A cyanobacterial sulfated carbohydrate polymer with emulsifying properties

“…Therefore, and as preliminary studies have shown, it has the versatility to be applied in different areas ranging from bioremediation to biomedicine; e.g. as a biosorbent for heavy metals bioremediation (Mota et al, 2016), as a vehicle for proteins or vitamins delivery (Estevinho et al, 2019;Leite et al, 2017;Mota, Tamagnini, Gales, Leite, & Pereira, 2018) and as anti-adhesive coatings (Costa et al, 2019). Moreover, the particular features of this carbohydrate polymer can be interesting for food and cosmetic industries, since similar polymers from other origins have been used as flocculants, thickening, hydrating, emulsifying and/or gelling agents, improving the product quality and texture.…”