1
|
Griveau L, Lafont M, le Goff H, Drouglazet C, Robbiani B, Berthier A, Sigaudo-Roussel D, Latif N, Visage CL, Gache V, Debret R, Weiss P, Sohier J. Design and characterization of an in vivo injectable hydrogel with effervescently generated porosity for regenerative medicine applications. Acta Biomater 2022; 140:324-337. [PMID: 34843951 DOI: 10.1016/j.actbio.2021.11.036] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/20/2021] [Accepted: 11/23/2021] [Indexed: 12/20/2022]
Abstract
Injectable hydrogels that polymerize directly in vivo hold significant promises in clinical settings to support the repair of damaged or failing tissues. Existing systems that allow cellular and tissue ingrowth after injection are limited because of deficient porosity and lack of oxygen and nutrient diffusion inside the hydrogels. Here is reported for the first time an in vivo injectable hydrogel in which the porosity does not pre-exist but is formed concomitantly with its in situ injection by a controlled effervescent reaction. The hydrogel tailorable crosslinking, through the reaction of polyethylene glycol with lysine dendrimers, allows the mixing and injection of precursor solutions from a dual-chamber syringe while entrapping effervescently generated CO2 bubbles to form highly interconnected porous networks. The resulting structures allow preserving modular mechanical properties (from 12.7 ± 0.9 to 29.9 ± 1.7 kPa) while being cytocompatible and conducive to swift cellular attachment, proliferation, in-depth infiltration and extracellular matrix deposition. Most importantly, the subcutaneously injected porous hydrogels are biocompatible, undergo tissue remodeling and support extensive neovascularisation, which is of significant advantage for the clinical repair of damaged tissues. Thus, the porosity and injectability of the described effervescent hydrogels, together with their biocompatibility and versatility of mechanical properties, open broad perspectives for various regenerative medicine or material applications, since effervescence could be combined with a variety of other systems of swift crosslinking. STATEMENT OF SIGNIFICANCE: A major challenge in hydrogel design is the synthesis of injectable formulations allowing easy handling and dispensing in the site of interest. However, the lack of adequate porosity inside hydrogels prevent cellular entry and, therefore, vascularization and tissue ingrowth, limiting the regenerative potential of a vast majority of injectable hydrogels. We describe here the development of an acellular hydrogel that can be injected directly in situ while allowing the simultaneous formation of porosity. Such hydrogel would facilitate handling through injection while providing a porous structure supporting vascularization and tissue ingrowth.
Collapse
Affiliation(s)
- Louise Griveau
- Laboratory for tissue biology and therapeutic engineering (LBTI), CNRS, Université de Lyon, UMR 5305, 7 Passage du Vercors, Lyon cedex 7 69367, France
| | - Marianne Lafont
- Université de Nantes, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, UMR 1229, Nantes F-44000, France
| | - Héloïse le Goff
- Université de Lyon, INSA-Lyon, MATEIS, UMR CNRS 5510-7 avenue Jean Capelle, F-69621, Villeurbanne, France
| | - Clémence Drouglazet
- Université de Lyon, INSA-Lyon, MATEIS, UMR CNRS 5510-7 avenue Jean Capelle, F-69621, Villeurbanne, France
| | - Baptiste Robbiani
- Université de Lyon, INSA-Lyon, MATEIS, UMR CNRS 5510-7 avenue Jean Capelle, F-69621, Villeurbanne, France
| | - Aurore Berthier
- Laboratory for tissue biology and therapeutic engineering (LBTI), CNRS, Université de Lyon, UMR 5305, 7 Passage du Vercors, Lyon cedex 7 69367, France
| | - Dominique Sigaudo-Roussel
- Laboratory for tissue biology and therapeutic engineering (LBTI), CNRS, Université de Lyon, UMR 5305, 7 Passage du Vercors, Lyon cedex 7 69367, France
| | - Najma Latif
- Imperial College London, Heart Science Centre, Harefield Hospital, Harefield, Middlesex UB9 6JH, UK
| | - Catherine Le Visage
- Université de Nantes, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, UMR 1229, Nantes F-44000, France
| | - Vincent Gache
- Institut NeuroMyogène (INMG), Muscle Nuclear and Cytoskeleton Architecture (MNCA), CNRS UMR 5310-INSERM U1217-UCBL1-Université de Lyon, 8 avenue Rockefeller, Lyon 69008. France
| | - Romain Debret
- Laboratory for tissue biology and therapeutic engineering (LBTI), CNRS, Université de Lyon, UMR 5305, 7 Passage du Vercors, Lyon cedex 7 69367, France
| | - Pierre Weiss
- Université de Nantes, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, UMR 1229, Nantes F-44000, France
| | - Jérôme Sohier
- Laboratory for tissue biology and therapeutic engineering (LBTI), CNRS, Université de Lyon, UMR 5305, 7 Passage du Vercors, Lyon cedex 7 69367, France.
| |
Collapse
|
2
|
Rajendan AK, Arisaka Y, Yui N, Iseki S. Polyrotaxanes as emerging biomaterials for tissue engineering applications: a brief review. Inflamm Regen 2020; 40:27. [PMID: 33292785 PMCID: PMC7657355 DOI: 10.1186/s41232-020-00136-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/07/2020] [Indexed: 02/06/2023] Open
Abstract
The field of tissue engineering and regeneration constantly explores the possibility of utilizing various biomaterials' properties to achieve effective and uneventful tissue repairs. Polyrotaxanes (PRXs) are supramolecular assemblies, which possess interesting mechanical property at a molecular scale termed as molecular mobility. This molecular mobility could be utilized to stimulate various cellular mechanosignaling elements, thereby altering the cellular functions. Apart from this, the versatile nature of PRXs such as the ability to form complex with growth factors and peptides, numerous sites for chemical modifications, and processability into different forms makes them interesting candidates for applications towards tissue engineering. This literature briefly reviews the concepts of PRXs and molecular mobility, the versatile nature of PRXs, and its emerging utility towards certain tissue engineering applications.
Collapse
Affiliation(s)
- Arun Kumar Rajendan
- Section of Molecular Craniofacial Embryology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan
| | - Yoshinori Arisaka
- Department of Organic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo, 101-0062, Japan
| | - Nobuhiko Yui
- Department of Organic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo, 101-0062, Japan
| | - Sachiko Iseki
- Section of Molecular Craniofacial Embryology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| |
Collapse
|
3
|
Wang C, Feng N, Chang F, Wang J, Yuan B, Cheng Y, Liu H, Yu J, Zou J, Ding J, Chen X. Injectable Cholesterol-Enhanced Stereocomplex Polylactide Thermogel Loading Chondrocytes for Optimized Cartilage Regeneration. Adv Healthc Mater 2019; 8:e1900312. [PMID: 31094096 DOI: 10.1002/adhm.201900312] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/26/2019] [Indexed: 01/12/2023]
Abstract
Ideal cartilage tissue engineering requires scaffolds featuring good biocompatibility, large pore structure, high mechanical strength, as well as minimal invasion procedure. Although significant progress has been made in the development of polymer scaffolds, the construction of smart systems with all the desired properties is still emerging as a challenge. The thermogels of stereocomplex 4-arm poly(ethylene glycol)-polylactide (PEG-PLA) (scPLAgel ) and stereocomplex cholesterol-modified 4-arm PEG-PLA (scPLA-Cholgel ) from the equimolar enantiomeric 4-arm PEG-PLA and 4-arm PEG-PLA-Chol, respectively, are fabricated as scaffolds for cartilage tissue engineering. scPLA-Cholgel shows lower critical gelation temperature, higher mechanical strength, larger pore size, better chondrocyte adhesion, and slower degradation compared to scPLAgel as the benefit of cholesterol modification, which is more appropriate for cartilage regeneration. Moreover, the preservation of morphology, biomechanical property, cartilaginous specific matrix, as well as cartilaginous gene expressions of engineered cartilage mediated by scPLA-Cholgel are proven superior to those by scPLAgel . scPLA-Cholgel serves as a promising chondrocyte carrier for cartilage tissue engineering and gives an alternative solution to clinical cartilage repair.
Collapse
Affiliation(s)
- Chenyu Wang
- Department of OrthopedicsThe Second Hospital of Jilin University Changchun 130041 P. R. China
| | - Naibo Feng
- Department of OrthopedicsThe Second Hospital of Jilin University Changchun 130041 P. R. China
| | - Fei Chang
- Department of OrthopedicsThe Second Hospital of Jilin University Changchun 130041 P. R. China
| | - Jincheng Wang
- Department of OrthopedicsThe Second Hospital of Jilin University Changchun 130041 P. R. China
| | - Baoming Yuan
- Department of OrthopedicsThe Second Hospital of Jilin University Changchun 130041 P. R. China
| | - Yilong Cheng
- Department of Applied ChemistrySchool of ScienceXi'an Jiaotong University Xi'an 710049 P. R. China
| | - He Liu
- Department of OrthopedicsThe Second Hospital of Jilin University Changchun 130041 P. R. China
| | - Jiakuo Yu
- Knee Surgery Department of the Institute of Sports MedicinePeking University Third Hospital Beijing 100191 P. R. China
| | - Jun Zou
- Department of Orthopaedic SurgeryThe First Affiliated Hospital of Soochow University Suzhou 215006 P. R. China
| | - Jianxun Ding
- Key Laboratory of Polymer EcomaterialsChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022 P. R. China
| | - Xuesi Chen
- Key Laboratory of Polymer EcomaterialsChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022 P. R. China
| |
Collapse
|
4
|
Supramolecular polymers based on cyclodextrins for drug and gene delivery. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2014; 125:207-49. [PMID: 20839082 DOI: 10.1007/10_2010_91] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Supramolecular polymers based on cyclodextrins (CDs) have inspired interesting and rapid developments as novel biomaterials in a broad range of drug and gene delivery applications, due to their low cytotoxicity, controllable size, and unique architecture. This review will summarize the potential applications of polyrotaxanes in the field of drug delivery and gene delivery. Generally, cyclodextrin-based biodegradable polypseudorotaxane hydrogels could be used as a promising injectable drug delivery system for sustained and controlled drug release. Temperature-responsive, pH-sensitive, and controllable hydrolyzable polyrotaxane hydrogels have attracted much attention because of their controllable properties, and the self-assembly micelles formed by amphiphilic copolymer threaded with CDs could be used as a carrier for controlled and sustained drug release. Polyrotaxanes with drug or ligand conjugated CDs threaded on a polymer chain with a biodegradable end group could be useful for controlled and multivalent targeted delivery. In the field of gene delivery, cationic polyrotaxanes consisting of multiple OEI-grafted CDs threaded on a block copolymer chain are attractive non-viral gene carries due to the strong DNA-binding ability, low cytotoxicity, and high gene delivery capability. Furthermore, cytocleavable end-caps were introduced in the polyrotaxane systems in order to ensure efficient endosomal escape for intracellular trafficking of DNA. The development of the supramolecular approach using CD-containing polyrotaxanes is expected to provide a new paradigm for biomaterials.
Collapse
|
5
|
Singh A, Zhan J, Ye Z, Elisseeff JH. Modular multifunctional poly(ethylene glycol) hydrogels for stem cell differentiation. ADVANCED FUNCTIONAL MATERIALS 2013; 23:575-582. [PMID: 32063822 PMCID: PMC7021251 DOI: 10.1002/adfm.201201902] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Synthetic polymers are employed to create highly defined microenvironments with controlled biochemical and biophysical properties for cell culture and tissue engineering. Chemical modification is required to input biological or chemical ligands, which often changes the fundamental structural properties of the material. Here, we report on a simple modular biomaterial design strategy that employs functional cyclodextrin nanobeads threaded onto poly(ethylene glycol) polymer necklaces to form multifunctional hydrogels. Nanobeads with desired chemical or biological functionalities can be simply threaded onto the PEG chains to form hydrogels, creating an accessible platform for users. We describe the design and synthesis of these multifunctional hydrogels, elucidate structure-property relationships, and demonstrate applications ranging from stem cell culture and differentiation to tissue engineering.
Collapse
Affiliation(s)
- Anirudha Singh
- 400 N. Broadway, Robert H. & Clarice Smith Building, Wilmer Eye Institute & Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD-21231, USA
| | - Jianan Zhan
- 400 N. Broadway, Robert H. & Clarice Smith Building, Wilmer Eye Institute & Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD-21231, USA
| | - Zhaoyang Ye
- The State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai-200237, China
| | - Jennifer H. Elisseeff
- 400 N. Broadway, Robert H. & Clarice Smith Building, Wilmer Eye Institute & Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD-21231, USA
| |
Collapse
|
6
|
Fujimoto M, Isobe M, Yamaguchi S, Amagasa T, Watanabe A, Ooya T, Yui N. Poly(ethylene glycol) hydrogels cross-linked by hydrolyzable polyrotaxane containing hydroxyapatite particles as scaffolds for bone regeneration. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 16:1611-21. [PMID: 16366340 DOI: 10.1163/156856205774576664] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Poly(ethylene glycol) (PEG) hydrogels cross-linked by a hydrolyzable polyrotaxane containing hydroxyapatite particles (PRX-HAp) were developed as scaffolds for bone regeneration. Five scaffolds with various composition of the polyrotaxane, PEG and HAp particles were prepared to examine cell adhesion in vitro using rat primary cultured osteoblast. Cells were observed to attach well on a PRX-HAp that have the same weight ratio of the polyrotaxane and HAp particles at 7 days after seeding. These results indicate that HAp particles are necessary for cell adhesion and survival, but a higher ratio of the particles is not suitable for cell adhesion. The composites of rat osteoblast and the PRX-HAp were implanted subcutaneously in syngeneic rats and harvested at 5 weeks after implantation. In histological analysis, osteoblast-like cells became arrayed along the surface of the PRX-HAp, and osteoid-like tissues were observed in the region between a queue of osteoblast-like cells and PRX-HAp. These images are similar to intramembranous ossification, and it is expected that bone regeneration occurs on the surface of the PRX-HAp. This study strongly suggests the great potential of the PRX-HAp as scaffolds for bone regeneration.
Collapse
Affiliation(s)
- Mariko Fujimoto
- Maxillofacial Surgery, Maxillofacial Reconstruction and Function, Division of Maxillofacial and Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
7
|
Li JJ, Zhao F, Li J. Polyrotaxanes for applications in life science and biotechnology. Appl Microbiol Biotechnol 2011; 90:427-43. [PMID: 21360153 DOI: 10.1007/s00253-010-3037-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 11/23/2010] [Accepted: 11/23/2010] [Indexed: 11/24/2022]
Abstract
Due to their low cytotoxicity, controllable size, and unique architecture, cyclodextrin (CD)-based polyrotaxanes and polypseudorotaxanes have inspired interesting exploitation as novel biomaterials. This review will update the recent progress in the studies on the structures of polyrotaxanes and polypseudorotaxanes based on different CDs and polymers, followed by summarizing their potential applications in life science and biotechnology, such as drug delivery, gene delivery, and tissue engineering. CD-based biodegradable polypseudorotaxane hydrogels could be used as promising injectable drug delivery systems for sustained and controlled drug release. Polyrotaxanes with drug or ligand-conjugated CDs threaded on polymer chain with biodegradable end group could be useful for controlled and multivalent targeting delivery. Cationic polyrotaxanes consisting of multiple oligoethylenimine-grafted CDs threaded on a block copolymer chain were attractive non-viral gene carries due to the strong DNA-binding ability, low cytotoxicity, and high gene transfection efficiency. Cytocleavable end caps were also introduced in the polyrotaxane systems in order to ensure efficient endosomal escape for intracellular trafficking of DNA. Finally, hydrolyzable polyrotaxane hydrogels with cross-linked α-CDs could be a desirable scaffold for cartilage and bone tissue engineering.
Collapse
Affiliation(s)
- Jia Jing Li
- Division of Bioengineering, Faculty of Engineering, National University of Singapore, 7 Engineering Drive 1, Singapore 117574, Republic of Singapore
| | | | | |
Collapse
|
8
|
Biodegradable Polymeric Assemblies for Biomedical Materials. POLYMERS IN NANOMEDICINE 2011. [DOI: 10.1007/12_2011_160] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
9
|
van de Manakker F, Vermonden T, van Nostrum CF, Hennink WE. Cyclodextrin-based polymeric materials: synthesis, properties, and pharmaceutical/biomedical applications. Biomacromolecules 2010; 10:3157-75. [PMID: 19921854 DOI: 10.1021/bm901065f] [Citation(s) in RCA: 425] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This review describes the synthesis, properties, and, in particular, biomedical and pharmaceutical applications of an upcoming class of polymeric networks and assemblies based on cyclodextrins (CDs). CDs are cyclic oligosaccharides composed of alpha-1,4-coupled d-glucose units, which contain a hydrophobic internal cavity that can act as a host for various, generally lipophilic, guest molecules. Because of this unique physicochemical property, commonly referred to as inclusion complex formation, CDs have often been used to design polymeric materials, such as hydrogels and nanoparticles. Polymeric systems based on CDs exhibit unique characteristics in terms of mechanical properties, stimuli-responsiveness, and drug release characteristics. In this contribution, first, an outline is given of covalently cross-linked polymeric networks in which CD moieties were structurally incorporated to modulate the network strength as well as the complexation and release of low molecular weight drugs. Second, physically assembled polymeric systems are discussed, of which the formation is accomplished by inclusion complexes between polymer-conjugated CDs and various guest molecule-derivatized polymers. Due to their physical nature, these polymeric systems are sensitive to external stimuli, such as temperature changes, shear forces and the presence of competing CD-binding molecules, which can be exploited to use these systems as injectable, in situ gelling devices. In recent years, many interesting CD-containing polymeric systems have been described in literature. These systems have to be optimized and extensively evaluated in preclinical studies concerning their safety and efficacy, making future clinical applications of these materials in the biomedical and pharmaceutical field feasible.
Collapse
Affiliation(s)
- Frank van de Manakker
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Sorbonnelaan 16, P.O. Box 80082, 3508 TB Utrecht, The Netherlands
| | | | | | | |
Collapse
|
10
|
Nielsen AL, Andersen MBO, Bugge TV, Nielsen CF, Nielsen TB, Wimmer R, Yu D, Larsen KL. Use of β‐cyclodextrins to control the structure of water‐soluble copolymers with hydrophobic parts. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pola.23704] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- A. L. Nielsen
- Department of Chemistry and Water Technology, Danish Technological Institute, Kongsvang Allé 29, 8000 Aarhus, Denmark
| | - M. B. O. Andersen
- Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg DK‐9000, Denmark
| | - T. V. Bugge
- Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg DK‐9000, Denmark
| | - C. F. Nielsen
- Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg DK‐9000, Denmark
| | - T. B. Nielsen
- Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg DK‐9000, Denmark
| | - R. Wimmer
- Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg DK‐9000, Denmark
| | - D. Yu
- Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg DK‐9000, Denmark
| | - K. L. Larsen
- Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg DK‐9000, Denmark
| |
Collapse
|
11
|
|
12
|
Loethen S, Ooya T, Choi HS, Yui N, Thompson DH. Synthesis, Characterization, and pH-Triggered Dethreading of α-Cyclodextrin-Poly(ethylene glycol) Polyrotaxanes Bearing Cleavable Endcaps. Biomacromolecules 2006; 7:2501-6. [PMID: 16961310 DOI: 10.1021/bm0602076] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The synthesis, characterization, and degradation kinetics of three alpha-cyclodextrin (alpha-CD)-poly(ethylene glycol) (PEG) polyrotaxanes with endcaps that were installed using Cu(I)-catalyzed Huisgen cyclization is reported. PEG1500, azidated with azidoacetic acid, was threaded with alpha-CD to form a pseudopolyrotaxane that was then capped in up to 82% yield with three different substituents to provide polyrotaxanes that were either acid-, base-, or fluoride-sensitive. NMR, GPC, XRD, and AFM methods were used to characterize the polyrotaxanes. Dethreading rates upon exposure to mild deprotection conditions were monitored by turbidity analysis. The vinyl ether-endcapped polyrotaxane is stable at pH 7 for 16 h but is solubilized at approximately 0.0211 min(-1) at pH 4. The ester-endcapped polyrotaxane is solubilized at 0.0122 min(-1) at pH 12.1. Our results show that pH-triggerable polyrotaxanes can be readily and efficiently prepared from pseudopolyrotaxanes in high yield by Huisgen cyclization of azido- and alkynyl-modified precursors in the presence of Cu(I).
Collapse
Affiliation(s)
- Scott Loethen
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, USA
| | | | | | | | | |
Collapse
|
13
|
Belitsky JM, Nelson A, Stoddart JF. Monitoring cyclodextrin-polyviologen pseudopolyrotaxanes with the Bradford assay. Org Biomol Chem 2005; 4:250-6. [PMID: 16391767 DOI: 10.1039/b509576j] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Self-assembled multivalent pseudopolyrotaxanes, composed of lactoside-bearing cyclodextrin (CD) rings threaded on linear polyviologen polymers, have been introduced recently as flexible and dynamic neoglycoconjugates. In the course of this research, it was found that polyviologens are responsive to the Bradford assay, which is traditionally highly selective for proteins. The response of the pseudopolyrotaxanes to the Bradford assay was dependant on, and thus indicative of, the degree of threading of the CD rings onto the polyelectrolyte. The assay was then used to report on the threading and dethreading of native and lactoside-bearing alpha-CD rings onto and off of polyviologen chains, a phenomenon which demonstrates the utility of biochemical assays to address problems unique to supramolecular chemistry.
Collapse
Affiliation(s)
- Jason M Belitsky
- California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1569, USA
| | | | | |
Collapse
|
14
|
|