title: "Leaching or not leaching": an alternative approach to antimicrobial materials via copolymers containing crown ethers as active groups.
abstract: In this work, new copolymers containing either MMA and 18C6 crown-ether pendants, or PEG, MMA and 18C6 crown-ether pendants were synthesized to test the idea that sequestering structural alkali-earth ions from the bacterial outer membrane (OM) may lead to bacterial death. The copolymers were obtained either via uncontrolled radical polymerization or ATRP; the latter approached allowed us to produce not only linear copolymers but also branched Y-like structures. After checking for the capability of complexing magnesium and calcium ions, the antimicrobial activity of all copolymers was tested placing their casted plaques in contact with pure water E. coli suspensions. All plaques adsorbed alkali-earth ions and killed bacteria, albeit with different antimicrobial efficiencies. Differences in the latter characteristic were attributed to different plaque roughness. The role of the 18C6 crown-ether pendants was elucidated by pre-saturating plaques with Mg/Ca ions, the marked reduction in antimicrobial efficiency indicating that losing the latter from OM due to surface complexation does play an important role in killing bacteria at short (<5 h) contact times. At longer times, the mode of action is instead related to the poly-cationic nature acquired by the plaques due to ion sequestering.
authors.affiliation: Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy. lizzo@unisa.it.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-7451-5523
authors.initials: M
authors.lastname: De Rosa
authors.affiliation: Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy. lizzo@unisa.it.
authors.forename: G
authors.initials: G
authors.lastname: Vigliotta
authors.affiliation: Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy. lizzo@unisa.it.
authors.forename: A
authors.initials: A
authors.lastname: Soriente
authors.affiliation: Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy. lizzo@unisa.it.
authors.forename: V
authors.initials: V
authors.lastname: Capaccio
authors.affiliation: Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
authors.forename: G
authors.initials: G
authors.lastname: Gorrasi
authors.affiliation: Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
authors.forename: R
authors.initials: R
authors.lastname: Adami
authors.affiliation: Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
authors.forename: E
authors.initials: E
authors.lastname: Reverchon
authors.affiliation: Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio, 11, 22100 Como, Italy. massimo.mella@uninsubria.it.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-7227-9715
authors.initials: M
authors.lastname: Mella
authors.affiliation: Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy. lizzo@unisa.it.
authors.forename: L
authors.identifier: http://orcid.org/0000-0002-0578-5631
authors.initials: L
authors.lastname: Izzo
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology*; D002118:Calcium / Q000737:chemistry / Q000494:pharmacology; D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology; D043844:Crown Ethers / Q000737:chemistry* / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000188:drug therapy; D006801:Humans; D008274:Magnesium / Q000737:chemistry / Q000494:pharmacology; D020366:Methylmethacrylate / Q000737:chemistry / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D056831:Coordination Complexes; D043844:Crown Ethers; D020366:Methylmethacrylate; D011092:Polyethylene Glycols; D008274:Magnesium; D002118:Calcium