High-throughput synthesis of CeO2 nanoparticles for transparent nanocomposites repelling Pseudomonas aeruginosa biofilms

Abstract

Preventing bacteria from adhering to material surfaces is an important technical problem and a major cause of infection. One of nature’s defense strategies against bacterial colonization is based on the biohalogenation of signal substances that interfere with bacterial communication. Biohalogenation is catalyzed by haloperoxidases, a class of metal-dependent enzymes whose activity can be mimicked by ceria nanoparticles. Transparent CeO2/polycarbonate surfaces that prevent adhesion, proliferation, and spread of Pseudomonas aeruginosa PA14 were manufactured. Large amounts of monodisperse CeO2 nanoparticles were synthesized in segmented flow using a high-throughput microfluidic benchtop system using water/benzyl alcohol mixtures and oleylamine as capping agent. This reduced the reaction time for nanoceria by more than one order of magnitude compared to conventional batch methods. Ceria nanoparticles prepared by segmented flow showed high catalytic activity in halogenation reactions, which makes them highly efficient functional mimics of haloperoxidase enzymes. Haloperoxidases are used in nature by macroalgae to prevent formation of biofilms via halogenation of signaling compounds that interfere with bacterial cell–cell communication (“quorum sensing”). CeO2/polycarbonate nanocomposites were prepared by dip-coating plasma-treated polycarbonate panels in CeO2 dispersions. These showed a reduction in bacterial biofilm formation of up to 85% using P. aeruginosa PA14 as model organism. Besides biofilm formation, also the production of the virulence factor pyocyanin in is under control of the entire quorum sensing systems P. aeruginosa. CeO2/PC showed a decrease of up to 55% in pyocyanin production, whereas no effect on bacterial growth in liquid culture was observed. This indicates that CeO2 nanoparticles affect quorum sensing and inhibit biofilm formation in a non-biocidal manner.

In situ generation of H2O2 using CaO2 as peroxide storage depot for haloperoxidase mimicry with surface-tailored Bi-doped mesoporous CeO2 nanozymes

“…Thus, the bromination of phenol red to tetrabromophenol blue does not proceed. We do not show here again the biofilm inhibiting properties of the PES-BiCe-CaO 2 composites, because this has already been reported before for CeO 2 /paint, 26 Bi 0.2 CeO 1.9 O 1.95 /PES, 36 CeO 2 /polyurethane 54 or CeO 2−x /polycarbonate 61,62 composites.…”

A wheel-like polyoxometalate for haloperoxidase-inspired antibiofouling with H2O2in situ provided by electrocatalysis

“…[9][10][11] Learning from nature, HBrO generation ability means that vanadium haloperoxidases are prospective choices to combat biofouling. [12][13][14] However, as natural enzymes, vanadium haloperoxidases are subject to inherent disadvantages, such as poor stability, low reserves and high cost. [15][16][17] Artificial nanozymes are ideal substitutes for natural enzymes, including vanadium haloperoxidases.…”

Development and Characterization of Electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopapers Containing Cerium Oxide Nanoparticles for Active Food Packaging Applications

“…An alternative to common oxygen scavengers is cerium oxide (CeO 2 ), which has attracted much attention due to its capability to transition from Ce 3+ to Ce 4+ states reversibly, which is responsible for the catalytic, antioxidant, anti-inflammatory, and anti-bacterial activity characteristics of these nanoparticles [20]. CeO 2 NPs has numerous applications that include catalysis, biomedicine, energy, electrochemistry, photoelectronics, novel materials with enhanced antimicrobial, superhydrobophic, anticorrosive or mechanical properties or sensors, among others due to their special structure and atomic characteristics in comparison to other systems [21][22][23][24][25][26][27][28][29][30][31].…”

“…One of the most promising methods to incorporate these nanoparticles into biopolymeric matrixes is electrospinning [23]. This simple, cost-effective, and versatile technique generates ultrathin polymeric fibers with control of fiber diameters and porosity [24]. This technique offers advantages; the process is carried out at room temperature and provides optimum encapsulation efficiency, which maintains the bioactivity of the encapsulated substances and offers their sustained and controlled release.…”