1. Non-covalent small molecule partnership for redox-active films: Beyond polydopamine technology
- Author
-
Rita Argenziano, Maria Laura Alfieri, Youri Arntz, Rachele Castaldo, Davide Liberti, Daria Maria Monti, Gennaro Gentile, Lucia Panzella, Orlando Crescenzi, Vincent Ball, Alessandra Napolitano, Marco d'Ischia, Argenziano, Rita, Alfieri, Maria Laura, Arntz, Yourib, Castaldo, Rachele, Liberti, Davide, Maria Monti, Daria, Gentile, Gennaro, Panzella, Lucia, Crescenzi, Orlando, Ball, Vincent, Napolitano, Alessandra, and D'Ischia, Marco
- Subjects
Technology ,Indoles ,UV stressed HaCaT cell ,Polymers ,pH dependent hydrophobicity ,Reducing activity ,Yellowish homogeneous films ,Film component structural analysi ,Hexamethylenediamine ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,Methyl 5,6-dihydroxyindole-2-carboxylate ,Colloid and Surface Chemistry ,Redox active film ,UVA absorbing film ,Humans ,Oxidation-Reduction ,Non-covalent interaction - Abstract
Hypothesis: The possibility to use hexamethylenediamine (HMDA) to impart film forming ability to natural polymers including eumelanins and plant polyphenols endowed with biological activity and functional properties has been recently explored with the aim to broaden the potential of polydopamine (PDA)-based films overcoming their inherent limitations. 5,6-dihydroxyindole-2-carboxylic acid, its methyl ester (MeDHICA) and eumelanins thereof were shown to exhibit potent reducing activity. Experiments: MeDHICA and HMDA were reacted in aqueous buffer, pH 9.0 in the presence of different substrates to assess the film forming ability. The effect of different reaction parameters (pH, diamine chain length) on film formation was investigated. Voltammetric and AFM /SEM methods were applied for analysis of the film redox activity and morphology. HPLC, MALDI-MS and 1HNMR were used for chemical characterization. The film reducing activity was evaluated in comparison with PDA by chemical assays and using UV stressed human immortalized keratinocytes (HaCat) cells model. Findings: Regular and homogeneous yellowish films were obtained with moderately hydrophobic properties. Film deposition was optimal at pH 9, and specifically induced by HMDA. The film consisted of HMDA and monomeric MeDHICA accompanied by dimers/small oligomers, but no detectable MeDHICA/HMDA covalent conjugation products. Spontaneous assembly of self-organized networks held together mainly by electrostatic interactions of MeDHICA in the anion form and HMDA as the dication is proposed as film deposition mechanism. The film displayed potent reducing properties and exerted significant protective effects from oxidative stress on HaCaT
- Published
- 2022