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Pifferi V, Ferrari E, Manfredi A, Ferruti P, Alongi J, Ranucci E, Falciola L. Nanosponges by the oxo-Michael polyaddition of cyclodextrins as sorbents of water pollutants: the o-toluidine case. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:6592-6603. [PMID: 36001264 PMCID: PMC9894998 DOI: 10.1007/s11356-022-22501-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Hydrophilic cyclodextrin nanosponges were prepared by the oxo-Michael polyaddition in an aqueous solution at pH > 10 of α-, β-, and γ-cyclodextrin with 1,4-bisacryloylpiperazine or 2,2-bisacrylamidoacetic acid. These nanosponges and, for comparison purposes, their precursor cyclodextrins were tested as sorbents of o-toluidine, a carcinogenic wastewater contaminant, by monitoring the depletion of o-toluidine from a 10-4 M (10 ppm) aqueous solutions. To this aim, an innovative analytical procedure was used: The voltammetric peak currents of o-toluidine in linear sweep voltammetry experiments were registered using multi-walled carbon nanotubes-modified glassy carbon electrodes. The experimental sorption curves fitted a mono-exponential kinetic model, and the residual o-toluidine was 0.16 ppm, one order of magnitude lower than those of all other sorbents reported so far. The sorption capacities ranged from 88 to 199 µmol g-1 (10-21.3 mg g-1), equal to or higher than those of the parent cyclodextrins. All nanosponges were completely regenerated by extracting with methanol. After regeneration, the sorption capacity slightly improved, suggesting a rearrangement of the nanosponge network. Overall, it may be reasonably concluded that the cyclodextrin nanosponges reported in this paper warrant potential as o-toluidine exhaustive sorbents.
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Affiliation(s)
- Valentina Pifferi
- Dipartimento Di Chimica, Università Degli Studi Di Milano, via C. Golgi 19, 20133, Milano, Italy
| | - Elena Ferrari
- Dipartimento Di Chimica, Università Degli Studi Di Milano, via C. Golgi 19, 20133, Milano, Italy
| | - Amedea Manfredi
- Dipartimento Di Chimica, Università Degli Studi Di Milano, via C. Golgi 19, 20133, Milano, Italy
| | - Paolo Ferruti
- Dipartimento Di Chimica, Università Degli Studi Di Milano, via C. Golgi 19, 20133, Milano, Italy
| | - Jenny Alongi
- Dipartimento Di Chimica, Università Degli Studi Di Milano, via C. Golgi 19, 20133, Milano, Italy
| | - Elisabetta Ranucci
- Dipartimento Di Chimica, Università Degli Studi Di Milano, via C. Golgi 19, 20133, Milano, Italy
| | - Luigi Falciola
- Dipartimento Di Chimica, Università Degli Studi Di Milano, via C. Golgi 19, 20133, Milano, Italy.
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L-Arginine-Derived Polyamidoamine Oligomers Bearing at Both Ends β-Cyclodextrin Units as pH-Sensitive Curcumin Carriers. Polymers (Basel) 2022; 14:polym14153193. [PMID: 35956707 PMCID: PMC9371169 DOI: 10.3390/polym14153193] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 07/31/2022] [Accepted: 08/01/2022] [Indexed: 11/17/2022] Open
Abstract
The aza-Michael polyaddition of L-arginine and N,N′-methylene-bis-acrylamide gives the biocompatible and easily cell-internalized polyamidoamine ARGO7. By controlled synthesis, two ARGO7 oligomers, namely a trimer and a pentamer, bearing acrylamide terminal units, were obtained as precursors of the β-cyclodextrin-end-terminated oligomers P3 and P5, which have been shown to encapsulate curcumin at both pH 7.4 and 4.5. After lyophilization, P3- and P5-curcumin complexes gave stable water solutions. The apparent solubility of encapsulated curcumin was in the range 20–51 μg mL−1, that is, three orders of magnitude higher than the water solubility of free curcumin (0.011 μg mL−1). The drug release profiles showed induction periods both at pH levels 4.5 and 7.4, suggesting a diffusive release mechanism, as confirmed by kinetic studies. The release rate of curcumin was higher at pH 7.4 than at pH 4.5 and, in both cases, it was higher for the P5 complex. Encapsulated curcumin was more photostable than the free drug. Molecular mechanics and molecular dynamics simulations explain at atomistic level the formation of aggregates due to favorable van der Waals interactions. The drug molecules interact with the external surface of carriers or form inclusion complexes with the β-cyclodextrin cavities. The aggregate stability is higher at pH 4.5.
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Beduini A, Carosio F, Ferruti P, Ranucci E, Alongi J. Polyamidoamines Derived from Natural α-Amino Acids as Effective Flame Retardants for Cotton. Polymers (Basel) 2021; 13:polym13213714. [PMID: 34771271 PMCID: PMC8588117 DOI: 10.3390/polym13213714] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/20/2021] [Accepted: 10/26/2021] [Indexed: 01/10/2023] Open
Abstract
In this paper, bioinspired polyamidoamines (PAAs) were synthesized from N,N′-methylenebisacrylamide and nine natural α-amino acids: L-alanine, L-valine, L-leucine (M-LEU), L-histidine, L-serine, L-asparagine, L-glutamine (M-GLN), L-aspartic acid and L-glutamic acid (M-GLU) and their performance as flame retardants (FRs) for cotton were determined. The aim was to ascertain if the ability to protect cotton from fire by the process of intumescing, previously found for the glycine-derived M-GLY, was a general feature of α-amino acid-derived PAAs. None of the PAAs ignited by flame impingement, apart from M-LEU, which burned for a few seconds leaving 93% of residue. All of them formed carbon- and oxygen-rich, porous chars with a graphitic structure in the air at 350 °C, as revealed by X-ray photoelectron spectroscopy. All samples were tested as FRs for cotton by horizontal flame spread tests. At a 5% add-on, M-GLU and M-GLN extinguished the flame. The same results were obtained with all the other PAAs at a 7% add-on. The α-amino acid residues influenced the FR performance. The most effective were those that, by heating, were most suitable for producing thermally stable cyclic aromatic structures. All PAA-treated cotton samples, even when burning, left significant residues, which, according to scanning electron microscopy analysis, maintained the original cotton texture.
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Affiliation(s)
- Alessandro Beduini
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (A.B.); (P.F.); (E.R.)
| | - Federico Carosio
- Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Alessandria Campus, viale T. Michel, 15121 Alessandria, Italy;
| | - Paolo Ferruti
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (A.B.); (P.F.); (E.R.)
| | - Elisabetta Ranucci
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (A.B.); (P.F.); (E.R.)
| | - Jenny Alongi
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (A.B.); (P.F.); (E.R.)
- Correspondence: ; Tel.: +39–02-50314108
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Arioli M, Manfredi A, Alongi J, Ferruti P, Ranucci E. Highlight on the Mechanism of Linear Polyamidoamine Degradation in Water. Polymers (Basel) 2020; 12:E1376. [PMID: 32575401 PMCID: PMC7361999 DOI: 10.3390/polym12061376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/12/2020] [Accepted: 06/17/2020] [Indexed: 11/17/2022] Open
Abstract
This paper aims at elucidating the degradation mechanism of linear polyamidoamines (PAAs) in water. PAAs are synthesized by the aza-Michael polyaddition of prim-monoamines or bis-sec-amines with bisacrylamides. Many PAAs are water-soluble and have potential for biotechnological applications and as flame-retardants. PAAs have long been known to degrade in water at pH ≥ 7, but their degradation mechanism has never been explored in detail. Filling this gap was necessary to assess the suitability of PAAs for the above applications. To this aim, a small library of nine PAAs was expressly synthesized and their degradation mechanism in aqueous solution studied by 1H-NMR in different conditions of pH and temperature. The main degradation mechanism was in all cases the retro-aza-Michael reaction triggered by dilution but, in some cases, hints were detected of concurrent hydrolytic degradation. Most PAAs were stable at pH 4.0; all degraded at pH 7.0 and 9.0. Initially, the degradation rate was faster at pH 9.0 than at pH 7.0, but the percent degradation after 97 days was mostly lower. In most cases, at pH 7.0 the degradation followed first order kinetics. The degradation rates mainly depended on the basicity of the amine monomers. More basic amines acted as better leaving groups.
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Affiliation(s)
| | | | | | - Paolo Ferruti
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (M.A.); (A.M.); (J.A.)
| | - Elisabetta Ranucci
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (M.A.); (A.M.); (J.A.)
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Lazzari F, Alexander BD, Dalgliesh RM, Alongi J, Ranucci E, Ferruti P, Griffiths PC. pH-Dependent Chiral Recognition of D- and L-Arginine Derived Polyamidoamino Acids by Self-assembled Sodium Deoxycholate. Polymers (Basel) 2020; 12:E900. [PMID: 32295002 PMCID: PMC7240376 DOI: 10.3390/polym12040900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 01/27/2023] Open
Abstract
D- and L-arginine-based polyamidoamino acids, called D- and L-ARGO7, retain the chirality and acid/base properties of the parent -amino acids and show pH-dependent self-structuring in water. The ability of the ARGO7 chiral isomers to selectively interact with chiral biomolecules and/or surfaces was studied by choosing sodium deoxycholate (NaDC) as a model chiral biomolecule for its ability to self-assembly into globular micelles, showing enantio-selectivity. To this purpose, mixtures of NaDC with D-, L- or D,L-ARGO7, respectively, in water were analysed by circular dichroism (CD) spectroscopy and small-angle neutron scattering (SANS) at different levels of acidity expressed in terms of pD and concentrations. Differences in the CD spectra indicated chiral discrimination for NaDC/ARGO7 mixtures in the gel phase (pD 7.30) but not in the solution phase (pD 9.06). SANS measurements confirmed large scale structural perturbation induced by this chiral discrimination in the gel phase yet no modulation of the structure in the solution phase. Together, these techniques shed light on the mechanism by which ARGO7 stereoisomers modify the morphology of NaDC micelles as a function of pH. This work demonstrates chirality-dependent interactions that drive structural evolution and phase behaviour of NaDC, opening the way for designing novel smart drug delivery systems.
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Affiliation(s)
- Federica Lazzari
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (J.A.); (E.R.)
| | - Bruce D. Alexander
- Faculty of Engineering and Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent ME4 4TB, UK;
| | - Robert M. Dalgliesh
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK;
| | - Jenny Alongi
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (J.A.); (E.R.)
| | - Elisabetta Ranucci
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (J.A.); (E.R.)
| | - Paolo Ferruti
- Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy; (J.A.); (E.R.)
| | - Peter C. Griffiths
- Faculty of Engineering and Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent ME4 4TB, UK;
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