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Serres-Gómez M, González-Gaitano G, Kaldybekov DB, Mansfield EDH, Khutoryanskiy VV, Isasi JR, Dreiss CA. Supramolecular Hybrid Structures and Gels from Host-Guest Interactions between α-Cyclodextrin and PEGylated Organosilica Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10591-10602. [PMID: 30095271 DOI: 10.1021/acs.langmuir.8b01744] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Polypseudorotaxanes are polymer chains threaded by molecular rings that are free to unthread; these "pearl-necklace" can self-assemble further, leading to higher-order supramolecular structures with interesting functionalities. In this work, the complexation between α-cyclodextrin (α-CD), a cyclic oligosaccharide of glucopyranose units, and poly(ethylene glycol) (PEG) grafted to silica nanoparticles was studied. The threading of α-CD onto the polymeric chains leads to their aggregation into bundles, followed by either the precipitation of the inclusion complex or the formation of a gel phase, in which silica nanoparticles are incorporated. The kinetics of threading, followed by turbidimetry, revealed a dependence of the rate of complexation on the following parameters: the concentration of α-CD, temperature, PEG length (750, 4000, and 5000 g mol-1), whether the polymer is grafted or free in solution, and the density of grafting. Complexation is slower, and temperature has a higher impact on PEG grafted on silica nanoparticles compared to PEG free in solution. Thermodynamic parameters extracted from the transition-state theory showed that inclusion complex formation is favored with grafted PEG compared to free PEG and establishes a ratio of complexation of five to six ethylene oxide units per cyclodextrin. The complexation yields, determined by gravimetry, revealed that much higher yields are obtained with longer chains and higher grafting density. Thermogravimetric analysis and Fourier transform infrared spectroscopy on the inclusion complex corroborate the number of macrocycles threaded on the chains. A sol-gel transition was observed with the longer PEG chain (5k) at specific mixing ratios; oscillatory shear rheology measurements confirmed a highly solid-like behavior, with an elastic modulus G' of up to 25 kPa, higher than that in the absence of silica. These results thus provide the key parameters dictating inclusion complex formation between cyclodextrin and PEG covalently attached to colloidal silica and demonstrate a facile route toward soft nanoparticle gels based on host-guest interactions.
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Affiliation(s)
- Mariana Serres-Gómez
- Department of Chemistry , University of Navarra , 31080 Pamplona , Spain
- Institute of Pharmaceutical Science, School of Cancer & Pharmaceutical Sciences , King's College London , Franklin-Wilkins Building, 150 Stamford Street , SE1 9NH London , U.K
| | | | - Daulet B Kaldybekov
- Reading School of Pharmacy , University of Reading , Whiteknights, P.O. Box 224, RG6 6AD Reading , U.K
- Faculty of Chemistry and Chemical Technology , Al-Farabi Kazakh National University , Almaty 050040 , Kazakhstan
| | - Edward D H Mansfield
- Reading School of Pharmacy , University of Reading , Whiteknights, P.O. Box 224, RG6 6AD Reading , U.K
| | - Vitaliy V Khutoryanskiy
- Reading School of Pharmacy , University of Reading , Whiteknights, P.O. Box 224, RG6 6AD Reading , U.K
| | - José Ramón Isasi
- Department of Chemistry , University of Navarra , 31080 Pamplona , Spain
| | - Cécile A Dreiss
- Institute of Pharmaceutical Science, School of Cancer & Pharmaceutical Sciences , King's College London , Franklin-Wilkins Building, 150 Stamford Street , SE1 9NH London , U.K
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Sugikawa K, Kozawa K, Ueda M, Ikeda A. Size controlled fullerene nanoparticles prepared by guest exchange of γ-cyclodextrin complexes in water. RSC Adv 2016. [DOI: 10.1039/c6ra16513c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Fullerene nanoparticles (nCx; x = 60 or 70) with a monodisperse size and morphology are obtained through guest exchange of a γ-cyclodextrin (γ-CD) complex.
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Affiliation(s)
- Kouta Sugikawa
- Department of Applied Chemistry
- Graduate School of Engineering
- Hiroshima University
- Higashi-Hiroshima 739-8527
- Japan
| | - Kentaro Kozawa
- Department of Applied Chemistry
- Graduate School of Engineering
- Hiroshima University
- Higashi-Hiroshima 739-8527
- Japan
| | - Masafumi Ueda
- Department of Applied Chemistry
- Graduate School of Engineering
- Hiroshima University
- Higashi-Hiroshima 739-8527
- Japan
| | - Atsushi Ikeda
- Department of Applied Chemistry
- Graduate School of Engineering
- Hiroshima University
- Higashi-Hiroshima 739-8527
- Japan
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Huang K, Li L, Wang J, Zhou Z, Guo X. Tunable double-stranded inclusion complexes of γ-cyclodextrin threaded onto non-modified poly(ethylene glycol). Colloid Polym Sci 2015. [DOI: 10.1007/s00396-015-3788-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Travelet C, Schlatter G, Hébraud P, Brochon C, Lapp A, Hadziioannou G. Formation and self-organization kinetics of alpha-CD/PEO-based pseudo-polyrotaxanes in water. A specific behavior at 30 degrees C. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8723-8734. [PMID: 19301842 DOI: 10.1021/la900070v] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
alpha-Cyclodextrins (alpha-CDs) have the ability to form inclusion complexes with poly(ethylene oxide) (PEO) polymer chains. These pseudo-polyrotaxanes (PPRs) can be obtained by quenching an alpha-CD/PEO mixture in water from 70 degrees C down to a lower temperature (typically in the range from 5 to 30 degrees C) thanks to favorable interactions between alpha-CD cavities and PEO chains. Moreover, starting from a liquid alpha-CD/PEO mixture at a total mass fraction of 15% w/w at 70 degrees C, the formation of PPRs with time at a lower temperature induces a white physical gel with time, and phase separation is observed. We established that PPR molecules are exclusively found in the precipitated phase although unthreaded alpha-CD molecules and unthreaded PEO chains are in the liquid phase. At 30 degrees C, the physical gel formation is much slower than at 5 degrees C. At 30 degrees C, we established that, in a first step, alpha-CDs thread onto PEO chains, forming PPR molecules which are not in good solvent conditions in water. At a higher length scale, rapid aggregation of the PPR molecules occurs, and threaded alpha-CD-based nanocylinders form (cylinder length L = 5.7 nm and cylinder radius R = 4.7 nm). At a higher length scale, alpha-CD-based nanocylinders associate in a Gaussian way, engendering the formation of precipitated domains which are responsible for the high turbidity of the studied system. At the end of this first step (i.e., after 20 min), the system still remains liquid and the PPRs are totally formed. Then, in a second step (i.e., after 150 min), the system undergoes its reorganization characterized by a compacity increase of the precipitated domains and forms a physical gel. We found that PPRs are totally formed after 20 min at 30 degrees C and that the system stays in a nongel state up to 150 min. This opens new perspectives regarding the PPR chemical modification: between these two characteristic times, we can easily envisage an efficient chemical modification of the PPR molecules in water, as for instance an end-capping reaction leading to the synthesis of polyrotaxanes.
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Affiliation(s)
- Christophe Travelet
- Laboratoire d'Ingénierie des Polymères pour les Hautes Technologies, Ecole Européenne de Chimie, Polymères et Matériaux, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg cedex 2, France,
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