title: Multifunctional Thin Films and Coatings from Caffeic Acid and a Cross-Linking Diamine.
abstract: The exploitation of easily accessible and nontoxic natural catechol compounds for surface functionalization and coating is attracting growing interest for biomedical applications. We report herein the deposition on different substrates of chemically stable thin films by autoxidation of 1 mM caffeic acid (CA) solutions at pH 9 in the presence of equimolar amounts of hexamethylenediamine (HMDA). UV-visible, mass spectrometric, and solid state13C and15N NMR analysis indicated covalent incorporation of the amine during CA polymerization to produce insoluble trioxybenzacridinium scaffolds decorated with carboxyl and amine functionalities. Similar coatings are obtained by replacing CA with 4-methylcatechol (MC) in the presence of HMDA. No significant film deposition was detected in the absence of HMDA nor by replacing it with shorter chain ethylenediamine, or with monoamines. The CA/HMDA-based films resisted oxidative and reductive treatments, displayed efficient Fe(II) and Cu(II) binding capacity and organic dyes adsorption, and provided an excellent cytocompatible platform for growing embryonic stem cells. These results pointed to HMDA as an efficient cross-linking mediator of film deposition from natural catechols for surface functionalization and coatings.
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" , Via Cintia 4, I-80126 Naples, Italy.
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Iacomino
authors.affiliation: INM - Leibniz Institute for New Materials , Campus D2 2, 66123 Saarbrücken, Germany.
authors.forename: Julieta I
authors.identifier: 0000-0001-9510-7254
authors.initials: JI
authors.lastname: Paez
authors.affiliation: Institute of Chemistry and Technology of Polymers, National Council of Research (CNR), Via Campi Flegrei 34, Pozzuoli I-80078, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Avolio
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" , Via Cintia 4, I-80126 Naples, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carpentieri
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" , Via Cintia 4, I-80126 Naples, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Panzella
authors.affiliation: Department of Biology, University of Naples "Federico II" , Via Cintia 4, I-80126 Naples, Italy.
authors.forename: Geppino
authors.initials: G
authors.lastname: Falco
authors.affiliation: Department of Biology, University of Naples "Federico II" , Via Cintia 4, I-80126 Naples, Italy.
authors.forename: Elio
authors.initials: E
authors.lastname: Pizzo
authors.affiliation: Institute of Chemistry and Technology of Polymers, National Council of Research (CNR), Via Campi Flegrei 34, Pozzuoli I-80078, Italy.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Errico
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" , Via Cintia 4, I-80126 Naples, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Napolitano
authors.affiliation: INM - Leibniz Institute for New Materials , Campus D2 2, 66123 Saarbrücken, Germany.|Chemistry Department, Saarland University , 66123 Saarbrücken, Germany.
authors.forename: Aranzazu
authors.initials: A
authors.lastname: Del Campo
authors.affiliation: Department of Chemical Sciences, University of Naples "Federico II" , Via Cintia 4, I-80126 Naples, Italy.
authors.forename: Marco
authors.identifier: 0000-0002-7184-0029
authors.initials: M
authors.lastname: d'Ischia