title: pH-Controlled Cerium Oxide Nanoparticle Inhibition of Both Gram-Positive and Gram-Negative Bacteria Growth.
abstract: Here, the antibacterial activity of dextran-coated nanoceria was examined against Pseudomonas aeruginosa and Staphylococcus epidermidis by varying the dose, the time of treatment, and the pH of the solution. Findings suggested that dextran-coated nanoceria particles were much more effective at killing P. aeruginosa and S. epidermidis at basic pH values (pH = 9) compared to acidic pH values (pH = 6) due to a smaller size and positive surface charge at pH 9. At pH 9, different particle concentrations did cause a delay in the growth of P. aeruginosa, whereas impressively S. epidermidis did not grow at all when treated with a 500 μg/mL nanoceria concentration for 24 hours. For both bacteria, a 2 log reduction and elevated amounts of reactive oxygen species (ROS) generation per colony were observed after 6 hours of treatment with nanoceria at pH 9 compared to untreated controls. After 6 hours of incubation with nanoceria at pH 9, P. aeruginosa showed drastic morphological changes as a result of cellular stress. In summary, this study provides significant evidence for the use of nanoceria (+4) for a wide range of anti-infection applications without resorting to the use of antibiotics, for which bacteria are developing a resistance towards anyway.
authors.affiliation: Department of Chemical Engineering, Northeastern University, Boston, MA, 02115, USA.
authors.forename: Ece
authors.initials: E
authors.lastname: Alpaslan
authors.affiliation: Department of Bioengineering, Northeastern University, Boston, MA, 02115, USA.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Geilich
authors.affiliation: Department of Chemical Engineering, Northeastern University, Boston, MA, 02115, USA.|TUBITAK-MAM, Genetic Engineering &Biotechnology Research Institute, 41470, Gebze, Kocaeli, Turkey.
authors.forename: Hilal
authors.initials: H
authors.lastname: Yazici
authors.affiliation: Department of Chemical Engineering, Northeastern University, Boston, MA, 02115, USA.|Department of Bioengineering, Northeastern University, Boston, MA, 02115, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Webster
mesh_terms: D002563:Cerium / Q000737:chemistry / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000472:pathogenicity; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000472:pathogenicity
chemical_list: D002563:Cerium; C030583:ceric oxide