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Leudjo Taka A, Doyle BP, Carleschi E, Youmbi Fonkui T, Erasmus R, Fosso-Kankeu E, Pillay K, Mbianda XY. Spectroscopic characterization and antimicrobial activity of nanoparticle doped cyclodextrin polyurethane bionanosponge. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 115:111092. [PMID: 32600696 DOI: 10.1016/j.msec.2020.111092] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 04/25/2020] [Accepted: 05/10/2020] [Indexed: 11/16/2022]
Abstract
This study reports on the spectroscopic characterization and antimicrobial potency of polyurethane cyclodextrin co-polymerized phosphorylated multiwalled carbon nanotube-doped Ag-TiO2 nanoparticle (pMWCNT-CD/Ag-TiO2) bionanosponge nanocomposite. The synthesis of pMWCNT-CD/Ag-TiO2 bionanosponge nanocomposite was carried out through the combined processes of amidation and polymerization reactions as well as the sol-gel method. The native nanosponge cyclodextrin and phosphorylated multiwalled carbon nanotube-nanosponge CD (pMWCNT-CD) polyurethanes were also prepared, and their antimicrobial activities carried out for comparison purposes. The synthesized bionanosponge polyurethane materials were characterized using Fourier-transform infrared (FTIR) spectroscopy, Laser Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to give clear information regarding their structural, and dynamic physicochemical properties. The potency tests of the synthesized compounds were carried out against three bacterial strains Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and two fungal representatives Aspergillus ochraceus and Aspergillus fumigatus, using the disc diffusion method. Micro dilution and agar plating were used to determine the minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC), respectively. The results obtained revealed that pMWCNT-CD/Ag-TiO2 exhibits superior antibacterial and antifungal activities when compared to the other bionanosponge polymers tested. Thus, the bionanosponge polyurethane pMWCNT-CD/Ag-TiO2 nanocomposite can be considered as an active antimicrobial compound (AMC).
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Affiliation(s)
- Anny Leudjo Taka
- Department of Chemical Sciences, Centre for Nanomaterials Science Research, University of Johannesburg, Doornfontein, 2028, South Africa
| | - Bryan P Doyle
- Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park, 2006, Johannesburg, South Africa
| | - Emanuela Carleschi
- Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park, 2006, Johannesburg, South Africa
| | - Thierry Youmbi Fonkui
- Department of Biotechnology and Food Technology, University of Johannesburg, P.O. Box 17011, Doornfontein Campus, 2028, South Africa
| | - Rudolph Erasmus
- School of Physics, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Elvis Fosso-Kankeu
- Water Pollution Monitoring and Remediation Initiatives Research Group, School of Chemical and Minerals Engineering, Faculty of Engineering, North West University, Potchefstroom Campus, Potchefstroom, South Africa
| | - Kriveshini Pillay
- Department of Chemical Sciences, Centre for Nanomaterials Science Research, University of Johannesburg, Doornfontein, 2028, South Africa
| | - Xavier Y Mbianda
- Department of Chemical Sciences, Centre for Nanomaterials Science Research, University of Johannesburg, Doornfontein, 2028, South Africa.
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Lo Meo P, Mundo F, Terranova S, Conte P, Chillura Martino D. Water Dynamics at the Solid-Liquid Interface to Unveil the Textural Features of Synthetic Nanosponges. J Phys Chem B 2020; 124:1847-1857. [PMID: 32069049 PMCID: PMC7997571 DOI: 10.1021/acs.jpcb.9b11935] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
A fast-field-cycling
NMR investigation was carried out on a set
of polyurethane cyclodextrin nanosponges, in order to gain information
on their textural properties, which have been proven to be quite difficult
to assess by means of ordinary porosimetric techniques. Experiments
were performed on both dry and wet samples, in order to evaluate the
behavior of the “nonexchangeable” C-bound 1H nuclei, as well as the one of the mobile protons belonging to the
skeletal hydroxyl groups and the water molecules. The results acquired
for the wet samples accounted for the molecular mobility of water
molecules within the channels of the nanosponge network, leading back
to the possible pore size distribution. Owing to the intrinsic difficulties
involved in a quantitative assessment of the textural properties,
in the present study we alternatively propose an extension to nanosponges
of the concept of “connectivity”, which has been already
employed to discuss the properties of soils.
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Affiliation(s)
- Paolo Lo Meo
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, V.le delle Scienze ed. 17, 90128 Palermo, Italy
| | - Federico Mundo
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, V.le delle Scienze ed. 17, 90128 Palermo, Italy
| | - Samuele Terranova
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, V.le delle Scienze ed. 17, 90128 Palermo, Italy
| | - Pellegrino Conte
- Department of Agricultural, Food and Forest Sciences (SAAF), University of Palermo, V.le delle Scienze ed. 4, 90128 Palermo, Italy
| | - Delia Chillura Martino
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, V.le delle Scienze ed. 17, 90128 Palermo, Italy
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Elder RM, Zaccone A, Sirk TW. Identifying Nonaffine Softening Modes in Glassy Polymer Networks: A Pathway to Chemical Design. ACS Macro Lett 2019; 8:1160-1165. [PMID: 35619458 DOI: 10.1021/acsmacrolett.9b00505] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using molecular simulations and theory, we develop an explicit mapping of the contribution of molecular relaxation modes in glassy thermosets to the shear modulus, where the relaxations were tuned by altering the polarity of side groups. Specifically, motions at the domain, segmental, monomer, and atomic levels are taken from molecular dynamics snapshots and directly linked with the viscoelasticity through a framework based in the lattice dynamics of amorphous solids. This unique approach provides direct insight into the roles of chemical groups in the stress response, including the time scale and spatial extent of relaxations during mechanics. Two thermoset networks with differing concentrations of polar side groups were examined, dicyclopentadiene (DCPD) and 5-norbornene-2-methanol (NBOH). A machine learning method is found to be effective for quantifying large-scale correlated motions, while more local chemical relaxations are readily identified by direct inspection. The approach is broadly applicable and enables rapid predictions of the frequency-dependent modulus for any glass.
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Affiliation(s)
- Robert M. Elder
- Polymers Branch, U.S. Army Research Laboratory, Aberdeen Proving Ground, Baltimore, Maryland 21005, United States
- Bennett Aerospace, Inc., Cary, North Carolina 27518, United States
| | - Alessio Zaccone
- Department of Physics “A. Pontremoli”, University of Milan, via Celoria 16, 20133 Milan, Italy
- Department of Chemical Engineering and Biotechnology, University of Cambridge, CB3 0AS Cambridge, United Kingdom
| | - Timothy W. Sirk
- Polymers Branch, U.S. Army Research Laboratory, Aberdeen Proving Ground, Baltimore, Maryland 21005, United States
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Holomb R, Ihnatolia P, Mitsa O, Mitsa V, Himics L, Veres M. Modeling and first-principles calculation of low-frequency quasi-localized vibrations of soft and rigid As–S nanoclusters. APPLIED NANOSCIENCE 2019. [DOI: 10.1007/s13204-018-00948-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Scalambra F, Rudić S, Romerosa A. Molecular Insights into Bulk and Porous κ2
P,N
-PTA Metal-Organic Polymers by Simultaneous Raman Spectroscopy and Inelastic Neutron Scattering. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Franco Scalambra
- Áea de Química Inorgánica-CIESOL; Universidad de Almería; Carretera Sacramento s/n 04120 La Canada de San Urbano Spain
| | - Svemir Rudić
- ISIS Facility; STFC, Rutherford Appleton Laboratory; Chilton OX11 0QX Didcot UK
| | - Antonio Romerosa
- Áea de Química Inorgánica-CIESOL; Universidad de Almería; Carretera Sacramento s/n 04120 La Canada de San Urbano Spain
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6
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Sarkar S, Lin‐Gibson S. Computational Design of Photocured Polymers Using Stochastic Reaction–Diffusion Simulation. ADVANCED THEORY AND SIMULATIONS 2018. [DOI: 10.1002/adts.201800028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Swarnavo Sarkar
- Biosystems and Biomaterials Division National Institute of Standards and Technology Gaithersburg MD 20899 USA
| | - Sheng Lin‐Gibson
- Biosystems and Biomaterials Division National Institute of Standards and Technology Gaithersburg MD 20899 USA
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7
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Araujo CF, Nolasco MM, Ribeiro-Claro PJA, Rudić S, Silvestre AJD, Vaz PD, Sousa AF. Inside PEF: Chain Conformation and Dynamics in Crystalline and Amorphous Domains. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00192] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Catarina F. Araujo
- CICECO − Aveiro Institute of Materials, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Mariela M. Nolasco
- CICECO − Aveiro Institute of Materials, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Paulo J. A. Ribeiro-Claro
- CICECO − Aveiro Institute of Materials, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Svemir Rudić
- ISIS Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K
| | - Armando J. D. Silvestre
- CICECO − Aveiro Institute of Materials, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Pedro D. Vaz
- CICECO − Aveiro Institute of Materials, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal
- ISIS Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K
| | - Andreia F. Sousa
- CICECO − Aveiro Institute of Materials, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal
- CEMMPRE, Department of Chemical Engineering, University of Coimbra, 3030-790 Coimbra, Portugal
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8
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Rao MRP, Shirsath C. Enhancement of Bioavailability of Non-nucleoside Reverse Transciptase Inhibitor Using Nanosponges. AAPS PharmSciTech 2017; 18:1728-1738. [PMID: 27757921 DOI: 10.1208/s12249-016-0636-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/16/2016] [Indexed: 11/30/2022] Open
Abstract
Efavirenz is a non-nucleoside reverse transcriptase inhibitor which is chronically prescribed for HIV patients. However, it exhibits solubility-limited bioavailability. Aim of this work was to enhance the solubility and dissolution of the Biopharmaceutical Classification System (BCS) class II drug efavirenz, using beta-cyclodextrin-based nanosponges. Nanosponges have high drug loading capacity and are effective for solubility enhancement. Beta-cyclodextrin was crosslinked with carbonates in different ratios to prepare nanosponges. The nanosponges were loaded with efavirenz by solvent evaporation method and the nanosponge with higher drug loading capacity was selected for further studies. Binary and ternary complexes with EFA, NS, and PVP K30 were prepared and characterized by phase solubility, solution state interaction, saturation solubility, in vitro dissolution, and in vivo pharmacokinetics. Spectral analysis by Fourier transform infrared spectroscopy, powder X-ray diffraction, differential scanning calorimetry, and field emission scanning electron microscopy was performed. Results obtained from spectral characterization confirmed inclusion complexation. Stability constant for ternary complex was found to be 1997 lit/mole, which indicates stable complex formation. The saturation solubility was found to be 17-fold higher with ternary complex in distilled water and about 4-fold in simulated gastric fluid. In vitro dissolution was improved 3 folds with ternary complex. Ternary nanosponge complexes were found to have 2-fold increase in oral bioavailability of efavirenz as compared to plain drug.
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9
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Rossi B, Paciaroni A, Venuti V, Fadda GC, Melone L, Punta C, Crupi V, Majolino D, Mele A. SANS investigation of water adsorption in tunable cyclodextrin-based polymeric hydrogels. Phys Chem Chem Phys 2017; 19:6022-6029. [DOI: 10.1039/c7cp00331e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A quantitative law for the hydration-dependence of pore size in cyclodextrin-based hydrogels is provided by SANS experiments.
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Affiliation(s)
- B. Rossi
- Elettra - Sincrotrone Trieste
- 34149 Trieste
- Italy
- Department of Physics University of Trento
- 38123 Povo
| | - A. Paciaroni
- Department of Physics
- University of Perugia
- 06123 Perugia
- Italy
| | - V. Venuti
- Department of Physics and Earth Sciences
- University of Messina
- 98166 Messina
- Italy
| | - G. C. Fadda
- Laboratoire Léon Brillouin (CEA/CNRS)
- CEA Saclay
- 91191 Gif-sur-Yvette Cedex
- France
| | - L. Melone
- Department of Chemistry
- Materials and Chemical Engineering “G. Natta”
- Politecnico di Milano
- Piazza L. da Vinci 32
- Italy
| | - C. Punta
- Department of Chemistry
- Materials and Chemical Engineering “G. Natta”
- Politecnico di Milano
- Piazza L. da Vinci 32
- Italy
| | - V. Crupi
- Department of Physics and Earth Sciences
- University of Messina
- 98166 Messina
- Italy
| | - D. Majolino
- Department of Physics and Earth Sciences
- University of Messina
- 98166 Messina
- Italy
| | - A. Mele
- Department of Chemistry
- Materials and Chemical Engineering “G. Natta”
- Politecnico di Milano
- Piazza L. da Vinci 32
- Italy
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10
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Venuti V, Rossi B, Mele A, Melone L, Punta C, Majolino D, Masciovecchio C, Caldera F, Trotta F. Tuning structural parameters for the optimization of drug delivery performance of cyclodextrin-based nanosponges. Expert Opin Drug Deliv 2016; 14:331-340. [DOI: 10.1080/17425247.2016.1215301] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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11
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Swaminathan S, Cavalli R, Trotta F. Cyclodextrin-based nanosponges: a versatile platform for cancer nanotherapeutics development. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2016; 8:579-601. [PMID: 26800431 DOI: 10.1002/wnan.1384] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/19/2015] [Indexed: 01/09/2023]
Abstract
Nanosponges (NSs) are a new age branched cyclodextrin (CD) polymeric systems exhibiting tremendous potential in pharmaceutical, agro science, and biomedical applications. Over the past decade, different varieties of NS based on the type of CD and the crosslinker have been developed tailored for specific applications. NS technology has been instrumental in achieving solubilization, stabilization, sustained release, enhancement of activity, permeability enhancement, protein delivery, ocular delivery, stimuli sensitive drug release, enhancement of bioavailability, etc. There is a major explosion of research in the area of NS-aided cancer therapeutics. A wide of anticancer molecules both from a pharmacological and physicochemical perspective have been developed as NS formulations by several groups including ours. Our objective in this review is to capture a systematic and comprehensive snapshot of the state-of-the-art of NS-aided cancer therapeutics reported so far. This review will provide an ideal platform for both the formulation scientists working on new polymeric/drug development and cancer biologists/scientists to understand the current nanotechnologies in CD-based NS-aided cancer therapeutics. The scope of the review is limited to small molecules and CD-based NS. The review covers in detail the problems associated with anticancer small molecules, and the solution provided by CD-based NS specifically for camptothecin, curcumin, paclitaxel, tamoxifen, resveratrol, quercetin, oxygen-NS, temozolomide, doxorubicin, and 5-Fluorouracil. WIREs Nanomed Nanobiotechnol 2016, 8:579-601. doi: 10.1002/wnan.1384 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Shankar Swaminathan
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Roberta Cavalli
- Department of Drug Science and Technology, University of Torino, Turin, Italy
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12
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Rossi B, Venuti V, Mele A, Punta C, Melone L, D'Amico F, Gessini A, Crupi V, Majolino D, Trotta F, Masciovecchio C. Vibrational signatures of the water behaviour upon confinement in nanoporous hydrogels. Phys Chem Chem Phys 2016; 18:12252-9. [DOI: 10.1039/c5cp07936e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vibrational spectroscopy is used to investigate how the hydrogen-bond dynamics of water is influenced by nano-confinement and hydrophobic/hydrophilic solvation effects.
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Affiliation(s)
- B. Rossi
- Elettra – Sincrotrone Trieste
- 34149 Trieste
- Italy
- Department of Physics University of Trento and INSTM Local Unit
- Trento
| | - V. Venuti
- Department of Physics and Earth Sciences
- University of Messina
- 98166 Messina
- Italy
| | - A. Mele
- Department of Chemistry
- Materials and Chemical Engineering “G. Natta”
- Politecnico di Milano and INSTM local unit
- Milano
- Italy
| | - C. Punta
- Department of Chemistry
- Materials and Chemical Engineering “G. Natta”
- Politecnico di Milano and INSTM local unit
- Milano
- Italy
| | - L. Melone
- Department of Chemistry
- Materials and Chemical Engineering “G. Natta”
- Politecnico di Milano and INSTM local unit
- Milano
- Italy
| | - F. D'Amico
- Elettra – Sincrotrone Trieste
- 34149 Trieste
- Italy
| | - A. Gessini
- Elettra – Sincrotrone Trieste
- 34149 Trieste
- Italy
| | - V. Crupi
- Department of Physics University of Trento and INSTM Local Unit
- Trento
- Italy
| | - D. Majolino
- Department of Physics University of Trento and INSTM Local Unit
- Trento
- Italy
| | - F. Trotta
- Department of Chemistry
- University of Torino
- 10125 Torino
- Italy
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13
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Rossi B, Venuti V, D'Amico F, Gessini A, Mele A, Punta C, Melone L, Crupi V, Majolino D, Trotta F, Masciovecchio C. Toward an understanding of the thermosensitive behaviour of pH-responsive hydrogels based on cyclodextrins. SOFT MATTER 2015; 11:5862-5871. [PMID: 26107102 DOI: 10.1039/c5sm01093d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The molecular mechanism responsible for the thermosensitive behaviour exhibited by pH-responsive cyclodextrin-based hydrogels is explored here with the twofold aim of clarifying some basic aspects of H-bond interactions in hydrogel phases and contributing to a future engineering of cyclodextrin hydrogels for targeted delivery and release of bioactive agents. The degree of H-bond association of water molecules entrapped in the gel network and the extent of intermolecular interactions involving the hydrophobic/hydrophilic moieties of the polymer matrix are probed by UV Raman and IR experiments, in order to address the question of how these different and complementary aspects combine to determine the pH-dependent thermal activation exhibited by these hydrogels. Complementary vibrational spectroscopies are conveniently employed in this study with the aim of safely disentangling the spectral response arising from the two main components of the hydrogel systems, i.e. the polymer matrix and water solvent. The experimental evidence suggests that the dominant effects in the mechanism of solvation of cyclodextrin-based hydrogels are due to the changes occurring, upon increasing of temperature, in the hydrophobicity character of specific chemical moieties of the polymer, as triggered by pH variations. The achievements of this work corroborate the potentiality of the UV Raman scattering technique, in combination with more conventional IR experiments, to provide a "molecular view" of complex macroscopic phenomena exhibited in hydrogel phases.
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Affiliation(s)
- Barbara Rossi
- Elettra-Sincrotrone Trieste, Strada Statale 14 km 163.5, Area Science Park, 34149 Trieste, Italy.
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Rossi B, Venuti V, Paciaroni A, Mele A, Longeville S, Natali F, Crupi V, Majolino D, Trotta F. Thermal fluctuations in chemically cross-linked polymers of cyclodextrins. SOFT MATTER 2015; 11:2183-2192. [PMID: 25639345 DOI: 10.1039/c4sm02000f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The extent and nature of thermal fluctuations in the innovative class of cross-linked polymers called cyclodextrin nanosponges (CDNS) are investigated, on the picosecond time scale, through elastic and quasielastic neutron scattering experiments. Nanosponges are complex 3D polymer networks where covalent bonds connecting different cyclodextrin (CD) units and intra- and inter-molecular hydrogen-bond interactions cooperate to define the molecular architecture and fast dynamics of the polymer. The study presented here aims to clarify the nature of the conformational rearrangements activated by increasing temperature in the nanosponge polymer, and the constraints imposed by intra- and inter-molecular hydrogen-bond patterns on the internal dynamics of the macromolecule. The results suggest a picture, in which conformational rearrangements involving the torsion of the OH groups around the C-O bonds dominate the internal dynamics of the polymer over the picosecond time scale. Moreover, the estimated values of mean square displacements reveal that the motions of the hydrogen atoms in the nanosponges are progressively hampered as the cross-linking degree of the polymer is increased. Finally, the study of the molecular relaxations suggests a dynamical rearrangement of the hydrogen-bond networks, which is characterized by a jump diffusion motion of the more mobile hydrogen atoms belonging to the OH groups of the CD units. All these findings add further contribution to the rational comprehensive view of the dynamics of these macromolecules, which may be particularly beneficial in designing new drug-delivery systems with tuneable inclusion/release properties.
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Affiliation(s)
- Barbara Rossi
- Elettra - Sincrotrone Trieste, Strada Statale 14 km 163.5, Area Science Park, 34149 Trieste, Italy
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15
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Rossi B, Venuti V, Mele A, Punta C, Melone L, Crupi V, Majolino D, Trotta F, D’Amico F, Gessini A, Masciovecchio C. Probing the molecular connectivity of water confined in polymer hydrogels. J Chem Phys 2015; 142:014901. [DOI: 10.1063/1.4904946] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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16
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Rossi B, Venuti V, D'Amico F, Gessini A, Castiglione F, Mele A, Punta C, Melone L, Crupi V, Majolino D, Trotta F, Masciovecchio C. Water and polymer dynamics in a model polysaccharide hydrogel: the role of hydrophobic/hydrophilic balance. Phys Chem Chem Phys 2015; 17:963-71. [DOI: 10.1039/c4cp04045g] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The role of hydrophobicity/hydrophilicity balance in the gelation phenomena in water-swollen polymers is explored in a model polysaccharide hydrogel.
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17
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Venuti V, Rossi B, D'Amico F, Mele A, Castiglione F, Punta C, Melone L, Crupi V, Majolino D, Trotta F, Gessini A, Masciovecchio C. Combining Raman and infrared spectroscopy as a powerful tool for the structural elucidation of cyclodextrin-based polymeric hydrogels. Phys Chem Chem Phys 2015; 17:10274-82. [DOI: 10.1039/c5cp00607d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
UV Raman spectroscopy and infrared spectroscopy have been efficiently implemented for the structural and dynamic elucidation of cyclodextrin-based polymeric hydrogels.
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Bayle M, Combe N, Sangeetha NM, Viau G, Carles R. Vibrational and electronic excitations in gold nanocrystals. NANOSCALE 2014; 6:9157-9165. [PMID: 24979073 DOI: 10.1039/c4nr02185a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An experimental analysis of all elementary excitations--phonons and electron-holes--in gold nanocrystals has been performed using plasmon resonance Raman scattering. Assemblies of monodisperse, single-crystalline gold nanoparticles, specific substrates and specific experimental configurations have been used. Three types of excitations are successively analyzed: collective quasi-acoustical vibrations of the particles (Lamb's modes), electron-hole excitations (creating the so-called "background" in surface-enhanced Raman scattering) and ensembles of atomic vibrations ("bulk" phonons). The experimental vibrational density of states extracted from the latter contribution is successfully compared with theoretical estimations performed using atomic simulations. The dominant role of surface atoms over the core ones on lattice dynamics is clearly demonstrated. Consequences on the thermodynamic properties of nanocrystals such as the decrease of the characteristic Debye temperature are also considered.
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Affiliation(s)
- Maxime Bayle
- Université de Toulouse, CEMES CNRS, 29 rue Jeanne Marvig, BP 94347, 31055 Toulouse Cedex 4, France.
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