title: Tunable ZnO spheres with high anti-biofilm and antibacterial activity via a simple green hydrothermal route.
abstract: A family of distinct ZnO morphologies - hollow, compartmented, core-shell and full solid ZnO spheres, dispersed or interconnected - is obtained by a simple hydrothermal route, in the presence of the starch biopolymer. The zinc-carbonaceous precursors were characterized by infrared spectroscopy, thermal analysis and scanning electron microscopy, while the ZnO spheres, obtained after the thermal processing, were investigated by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, UV-VIS spectroscopy, photoluminescence measurements, antimicrobial, anti-biofilm and flow cytometry tests. The formation mechanism proposed for this versatile synthesis route is based on the gelling ability of amylose, one of the starch template constituents, responsible for the effective embedding of zinc cations into starch prior to its hydrothermal carbonization. The simple variation of the raw materials concentration dictates the type of ZnO spheres. The micro-sized ZnO spheres exhibit high antibacterial and anti-biofilm activity against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) reference and methicillin resistant clinical strains especially for Gram-negative biofilms (P. aeruginosa), demonstrating great potential for new ZnO anti-biofilm formulations.
authors.affiliation: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania.
authors.forename: Greta
authors.initials: G
authors.lastname: Patrinoiu
authors.affiliation: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania. Electronic address: josecalderonmoreno@yahoo.com.
authors.forename: José Maria
authors.initials: JM
authors.lastname: Calderón-Moreno
authors.affiliation: Department of Microbiology, Faculty of Biology, University of Bucharest, Research Institute of University of Bucharest, Ale. Portocalilor 1-3, 60101 Bucharest, Romania.
authors.forename: Carmen Mariana
authors.initials: CM
authors.lastname: Chifiriuc
authors.affiliation: Department of Microbiology, Faculty of Biology, University of Bucharest, Research Institute of University of Bucharest, Ale. Portocalilor 1-3, 60101 Bucharest, Romania.
authors.forename: Crina
authors.initials: C
authors.lastname: Saviuc
authors.affiliation: National Institute for Lasers, Plasma and Radiation Physics, Atomistilor 409, PO-Box MG-36, 077125 Magurele, Romania.
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Birjega
authors.affiliation: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania. Electronic address: ocarp@icf.ro.
authors.forename: Oana
authors.initials: O
authors.lastname: Carp
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010316:Particle Size; D016062:Porosity; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship; D013499:Surface Properties; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015034:Zinc Oxide
keywords: Antibacterial activity; Carbohydrates; Green chemistry; Structural design; ZnO