Fluorinated vs. Zwitterionic-Polymer Grafted Surfaces for Adhesion Prevention of the Fungal Pathogen Candida albicans

Abstract

Fluorinated (F6) and zwitterionic, as well as phosphorylcholine (MPC) and sulfobetaine (MSA), copolymers containing a low amount (1 and 5 mol%) of 3-(trimethoxysilyl)propyl methacrylate (PTMSi) were prepared and covalently grafted to glass slides by using the trimethoxysilyl groups as anchorage points. Glass-surface functionalization and polymer-film stability upon immersion in water were proven by contact angle and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) measurements. Antifouling performance of the grafted films was assayed against the yeast Candida albicans, the most common Candida species, which causes over 80% of candidiasis. Results revealed that the F6 fluorinated, hydrophobic copolymers performed much better in reducing the adhesion of C. albicans, with respect to both corresponding zwitterionic, hydrophilic MPC and MSA counterparts, and were similar to the glass negative control, which is well-known to inhibit the adhesion of C. albicans. A composition-dependent activity was also found, with the films of copolymer with 99 mol% F6 fluorinated co-units performing best.Polymers 2020, 12, 398 2 of 15 of sessile fungal cells, and removal of the infected device is often required [9]. However, removal of the contaminated implant can be accompanied by complications, negatively affecting the patient's condition and the economic burden. Therefore, prevention of biofilm-associated infections currently represents a major challenge.The surface properties, notably the surface chemical composition, of materials susceptible to fouling are known to significantly affect the biofilm formation on medical devices [11], as well as the micro-and macro-fouler colonization of ship hulls, maritime equipment and industrial implants [12][13][14][15]. One of the most promising strategies to overcome this problem is to develop anti(bio)fouling surfaces, which prevent microorganism adhesion.The first interactions occurring among C. albicans cells and materials surfaces are usually hydrophobic interactions and electrostatic forces, taking place within the first 12 h; subsequent stages involve a stronger adhesion, displayed by cell-wall glycoproteins (e.g., Als or Hwp1 proteins) [16]. This leads to formation of microcolonies (3-4 h) and biofilm aggregates organized in a bilayer composed of yeast and hyphal cells embedded in a self-produced extracellular polymeric matrix (11-30 h). C. albicans mature biofilm is then consolidated up to 38-72 h [17].Among the different parameters that are reported to possibly affect Candida adhesion, including surface preconditioning with different biological fluids [12], surface roughness [8-11] and surface charge [9], one of the most relevant is surface wettability. It is widely acknowledged that C. albicans attaches more rapidly to hydrophobic, nonpolar surfaces, such as Teflon and other plastics, than to hydrophilic surfaces, such as glass and metals [18]. However, results of these studies have at times been contradictory, due to the absence of standardized methods for determining surfa...

Amphiphilic Surface‐Active Methacrylic Urethane Additives for the Design of Photopolymerized Coatings with Great Potential for Marine Fouling‐Release Applications

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Sulfobetaine Hydrogels with a Complex Multilength-Scale Hierarchical Structure

“…Hydrogels have been explored for virtually all fields of engineering and technology. , Recent studies focus on biomaterials, − wound treatment, − drug delivery, ,,, (bone) tissue engineering, ,, soft electronics and robotics, − water treatment, − energy materials and management, ,− membranes, or superabsorbents. − In addition, sulfobetaine-based polymers show antifouling − and bactericidal , properties, making the respective hydrogels interesting candidates for medical, biological, and environmental applications . For example, He et al described [2-(methacryloyloxy)­ethyl]­dimethyl-(3 sulfopropyl)­ammonium hydroxide based hydrogels with poly­(ethylene glycol)­dimethacrylate as a crosslinker with different elastic moduli for wound healing .…”

Fluorescent Submicron-Sized Poly(heptafluoro-n-butyl methacrylate) Particles with Long-Term Stability

“…Fluorinated nanomaterials are often considered for biomedical applications. They are proposed as a way to manufacture grafted surfaces for adhesion prevention of fungal pathogens, such as Candida albicans [29] which causes over 80% of candidiasis. Fluorinated composites with graphene have been used as possible insulators for flexible electronics [30].…”