1
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Nguyen NT, Jennings J, Milani AH, Martino CDS, Nguyen LTB, Wu S, Mokhtar MZ, Saunders JM, Gautrot JE, Armes SP, Saunders BR. Highly Stretchable Conductive Covalent Coacervate Gels for Electronic Skin. Biomacromolecules 2022; 23:1423-1432. [PMID: 35188757 PMCID: PMC9098112 DOI: 10.1021/acs.biomac.1c01660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Highly stretchable electrically conductive hydrogels have been extensively researched in recent years, especially for applications in strain and pressure sensing, electronic skin, and implantable bioelectronic devices. Herein, we present a new cross-linked complex coacervate approach to prepare conductive hydrogels that are both highly stretchable and compressive. The gels involve a complex coacervate between carboxylated nanogels and branched poly(ethylene imine), whereby the latter is covalently cross-linked by poly(ethylene glycol) diglycidyl ether (PEGDGE). Inclusion of graphene nanoplatelets (Gnp) provides electrical conductivity as well as tensile and compressive strain-sensing capability to the hydrogels. We demonstrate that judicious selection of the molecular weight of the PEGDGE cross-linker enables the mechanical properties of these hydrogels to be tuned. Indeed, the gels prepared with a PEGDGE molecular weight of 6000 g/mol defy the general rule that toughness decreases as strength increases. The conductive hydrogels achieve a compressive strength of 25 MPa and a stretchability of up to 1500%. These new gels are both adhesive and conformal. They provide a self-healable electronic circuit, respond rapidly to human motion, and can act as strain-dependent sensors while exhibiting low cytotoxicity. Our new approach to conductive gel preparation is efficient, involves only preformed components, and is scalable.
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Affiliation(s)
- Nam T Nguyen
- Department of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - James Jennings
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Amir H Milani
- Department of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Chiara D S Martino
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, U.K
| | - Linh T B Nguyen
- Eastman Dental Institute, University College London, London WC1X 8LD, U.K
| | - Shanglin Wu
- Department of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Muhamad Z Mokhtar
- Department of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Jennifer M Saunders
- Department of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Julien E Gautrot
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, U.K
| | - Steven P Armes
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Brian R Saunders
- Department of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
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2
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Zhu M, Lu D, Milani AH, Mahmoudi N, King SM, Saunders BR. Comparing pH-responsive nanogel swelling in dispersion and inside a polyacrylamide gel using photoluminescence spectroscopy and small-angle neutron scattering. J Colloid Interface Sci 2022; 608:378-385. [PMID: 34626983 DOI: 10.1016/j.jcis.2021.09.163] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/18/2021] [Accepted: 09/26/2021] [Indexed: 10/20/2022]
Abstract
Nanosized probes that report their changes in dimensions within networks in response to environmental stimuli are potentially important for applications such as drug delivery, load-supporting hydrogels and soft robotics. Recently, we developed a fluorescent pH-responsive nanogel (NG) that used Förster-resonance energy transfer (FRET) to report changes in the probe separation and NG swelling within hydrogels using photoluminescence (PL) spectroscopy. However, FRET cannot measure nanoparticle dimensions and is subject to artefacts. Here, we report the use of small-angle neutron scattering (SANS) to study both the NGs in dispersion and in polyacrylamide (PAAm) gels as a function of pH. We compare the PL and SANS data for both systems and as a function of pH. The SANS data for the dispersed NGs indicate that they have a core-shell structure with a swollen mesh size of ∼1.0 nm. We hypothesized that the NGs inside the PAAm gel would show the same general changes in scattering as the pH is increased, as observed for the dispersed NGs, and this is confirmed by the data. In summary, the data confirm that PL is a suitable (accessible) method for reporting internal environmental changes within gels using NG probes.
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Affiliation(s)
- Mingning Zhu
- School of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, UK
| | - Dongdong Lu
- School of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, UK
| | - Amir H Milani
- School of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, UK
| | - Najet Mahmoudi
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | - Stephen M King
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | - Brian R Saunders
- School of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, UK
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3
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Binch ALA, Ratcliffe LPD, Milani AH, Saunders BR, Armes SP, Hoyland JA. Site-Directed Differentiation of Human Adipose-Derived Mesenchymal Stem Cells to Nucleus Pulposus Cells Using an Injectable Hydroxyl-Functional Diblock Copolymer Worm Gel. Biomacromolecules 2021; 22:837-845. [PMID: 33470795 DOI: 10.1021/acs.biomac.0c01556] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Adipose-derived mesenchymal stem cells (ASCs) have been identified for their promising therapeutic potential to regenerate and repopulate the degenerate intervertebral disk (IVD), which is a major cause of lower back pain. The optimal cell delivery system remains elusive but encapsulation of cells within scaffolds is likely to offer a decisive advantage over the delivery of cells in solution by ensuring successful retention within the tissue. Herein, we evaluate the use of a fully synthetic, thermoresponsive poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) (PGMA-PHPMA) diblock copolymer worm gel that mimics the structure of hydrophilic glycosaminoglycans. The objective was to use this gel to direct differentiation of human ASCs toward a nucleus pulposus (NP) phenotype, with or without the addition of discogenic growth factors TGFβ or GDF6. Accordingly, human ASCs were incorporated into a cold, free-flowing aqueous dispersion of the diblock copolymer, gelation induced by warming to 37 °C and cell culture was conducted for 14 days with or without such growth factors to assess the expression of characteristic NP markers compared to those produced when using collagen gels. In principle, the shear-thinning nature of the biocompatible worm gel enables encapsulated human ASCs to be injected into the IVD using a 21G needle. Moreover, we find significantly higher gene expression levels of ACAN, SOX-9, KRT8, and KR18 for ASCs encapsulated within worm gels compared to collagen scaffolds, regardless of the growth factors employed. In summary, such wholly synthetic worm gels offer considerable potential as an injectable cell delivery scaffold for the treatment of degenerate disk disease by promoting the transition of ASCs toward an NP-phenotype.
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Affiliation(s)
- Abbie L A Binch
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PL, U.K
| | - Liam P D Ratcliffe
- Department of Chemistry, University of Sheffield Brook Hill, Sheffield S3 7HF, South Yorkshire, U.K
| | - Amir H Milani
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
| | - Brian R Saunders
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
| | - Steven P Armes
- Department of Chemistry, University of Sheffield Brook Hill, Sheffield S3 7HF, South Yorkshire, U.K
| | - Judith A Hoyland
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PL, U.K.,NIHR Manchester Biomedical Research Centre, Central Manchester Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, U.K
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4
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Turton J, Worrall S, Musa MS, Milani AH, Yao Y, Shaw P, Ring D, Saunders BR. Effect of methacrylic acid and pendant vinyl groups on the mechanical properties of highly stretchable core–shell nanostructured films deposited from water. Polym Chem 2021. [DOI: 10.1039/d0py00971g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mechanical properties of these highly stretchable, water deposited elastomers can be tuned by varying MAA content and vinyl functionalisation.
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Affiliation(s)
- James Turton
- Department of Materials
- MSS Tower
- The University of Manchester
- Manchester
- U.K
| | - Stephen Worrall
- Aston Institute of Materials Research
- School of Engineering and Applied Science
- Aston University
- Birmingham
- U.K
| | | | - Amir H. Milani
- Department of Materials
- MSS Tower
- The University of Manchester
- Manchester
- U.K
| | - Yichao Yao
- Department of Materials
- MSS Tower
- The University of Manchester
- Manchester
- U.K
| | | | | | - Brian R. Saunders
- Department of Materials
- MSS Tower
- The University of Manchester
- Manchester
- U.K
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5
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Wu S, Zhu M, Lu D, Milani AH, Lian Q, Fielding LA, Saunders BR, Derry MJ, Armes SP, Adlam D, Hoyland JA. Self-curing super-stretchable polymer/microgel complex coacervate gels without covalent bond formation. Chem Sci 2019; 10:8832-8839. [PMID: 31803457 PMCID: PMC6849882 DOI: 10.1039/c9sc02555c] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 08/02/2019] [Indexed: 12/25/2022] Open
Abstract
Elastic physical gels are highly desirable because they can be conveniently prepared and readily shaped. Unfortunately, many elastic physical gels prepared in water require in situ free-radical polymerization during the gel formation stage. In contrast, complex coacervate gels are physical gels that can be prepared by simply mixing two pre-formed oppositely-charged polyelectrolytes. However, as far as we are aware, highly elastic complex coacervate gels have not yet been reported. Herein, we combine polyanionic microgel particles with a well-known commercially-available cationic polyelectrolyte to prepare polymer/microgel complex coacervate (PMCC) physical gels. This new family of gels requires annealing at only 37 °C and behaves like a covalent gel but does not form covalent bonds. Thermal reconfiguration of the dynamic ionic bonds transforms the shapeable pre-gel into a highly elastic gel that is super-stretchable, adhesive, self-healing, highly swellable and can be further toughened using Ca2+ as an ionic crosslinker. Our PMCC gels have excellent potential for applications as engineering gels and structural biomaterials, as well as for wound healing and water purification.
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Affiliation(s)
- Shanglin Wu
- School of Materials , University of Manchester , MSS Tower , Manchester , M13 9PL , UK . ;
| | - Mingning Zhu
- School of Materials , University of Manchester , MSS Tower , Manchester , M13 9PL , UK . ;
| | - Dongdong Lu
- School of Materials , University of Manchester , MSS Tower , Manchester , M13 9PL , UK . ;
| | - Amir H Milani
- School of Materials , University of Manchester , MSS Tower , Manchester , M13 9PL , UK . ;
| | - Qing Lian
- School of Materials , University of Manchester , MSS Tower , Manchester , M13 9PL , UK . ;
| | - Lee A Fielding
- School of Materials , University of Manchester , MSS Tower , Manchester , M13 9PL , UK . ;
| | - Brian R Saunders
- School of Materials , University of Manchester , MSS Tower , Manchester , M13 9PL , UK . ;
| | - Matthew J Derry
- Department of Chemistry , The University of Sheffield , Dainton Building, Brook Hill , Sheffield , South Yorkshire S3 7HF , UK
| | - Steven P Armes
- Department of Chemistry , The University of Sheffield , Dainton Building, Brook Hill , Sheffield , South Yorkshire S3 7HF , UK
| | - Daman Adlam
- Division of Cell Matrix Biology and Regenerative Medicine , Faculty of Biology, Medicine and Health , University of Manchester , Oxford Road , Manchester , M13 9PT , UK
| | - Judith A Hoyland
- Division of Cell Matrix Biology and Regenerative Medicine , Faculty of Biology, Medicine and Health , University of Manchester , Oxford Road , Manchester , M13 9PT , UK
- NIHR Manchester Biomedical Research Centre , Central Manchester Foundation Trust , Manchester Academic Health Science Centre , Manchester , M13 9WL , UK
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6
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Shanks HR, Milani AH, Lu D, Saunders BR, Carney L, Adlam DJ, Hoyland JA, Blount C, Dickinson M. Core-Shell-Shell Nanoparticles for NIR Fluorescence Imaging and NRET Swelling Reporting of Injectable or Implantable Gels. Biomacromolecules 2019; 20:2694-2702. [PMID: 31185170 PMCID: PMC7007186 DOI: 10.1021/acs.biomac.9b00463] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/31/2019] [Indexed: 11/29/2022]
Abstract
Injectable gels that support load are desirable for restoring the mechanical properties of degenerated load-bearing tissue. As these gels become increasingly sophisticated, the need to remotely image them and monitor their swelling increases. However, imaging such gels and monitoring their swelling using noninvasive means is challenging. Here, we use a very low concentration of near-infrared (NIR) core-shell-shell (CSS) reporter nanoparticles to both image and monitor swelling changes of two load-supporting gels. The load-supporting injectable gel consisted of covalently interlinked pH-responsive microgel (MG) particles. The latter gel was not cytotoxic and is termed a doubly cross-linked microgel (DX MG). Inclusion of a complementary fluorescent dye enabled ratiometric monitoring of gel swelling changes in response to pH via nonradiative resonance energy transfer (NRET). In addition, changes in the CSS nanoparticle emission intensity provided a NIR-only method that could also be used to monitor gel swelling. The gel was able to be imaged using NIR light, after being subcutaneously injected into a tissue model. To demonstrate versatility of our approach, CSS and the dye were included within a model implantable gel (poly(acrylamide/acrylic acid)) and fluorescent detection of swelling investigated. Because the concentrations of the reporting species were too low to affect the mechanical properties, our approach to remote gel imaging and swelling monitoring has good potential for application in injectable gels and implants.
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Affiliation(s)
- Hannah R. Shanks
- School
of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, U.K.
| | - Amir H. Milani
- School
of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, U.K.
| | - Dongdong Lu
- School
of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, U.K.
| | - Brian R. Saunders
- School
of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, U.K.
| | - Louise Carney
- School
of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, U.K.
| | - Daman J. Adlam
- Division
of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology,
Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, U.K.
| | - Judith A. Hoyland
- Division
of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology,
Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, U.K.
- NIHR
Manchester Biomedical Research Centre, Manchester University NHS Foundation
Trust, Manchester Academic Health Science
Centre, Manchester, M20 2LR, U.K.
| | - Christopher Blount
- Photon
Science Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, U.K.
- School
of Physics & Astronomy, University of
Manchester, Oxford Road, Manchester, M13 9PL, U.K.
| | - Mark Dickinson
- Photon
Science Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, U.K.
- School
of Physics & Astronomy, University of
Manchester, Oxford Road, Manchester, M13 9PL, U.K.
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7
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Nguyen NT, Milani AH, Jennings J, Adlam DJ, Freemont AJ, Hoyland JA, Saunders BR. Highly compressive and stretchable poly(ethylene glycol) based hydrogels synthesised using pH-responsive nanogels without free-radical chemistry. Nanoscale 2019; 11:7921-7930. [PMID: 30964497 DOI: 10.1039/c9nr01535c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Poly(ethylene glycol) (PEG) based hydrogels are amongst the most studied synthetic hydrogels. However, reports on PEG-based hydrogels with high mechanical strength are limited. Herein, a class of novel, well-defined PEG-based nanocomposite hydrogels with tunable mechanical strength are synthesised via ring-opening reactions of diglycidyl ethers with carboxylate ions. The pH responsive crosslinked polyacid nanogels (NG) in the dispersed phase act as high functionality crosslinkers which covalently bond to the poly(ethylene glycol) diglycidyl ethers (PEGDGE) as the continuous matrix. A series of NG-x-PEG-y-z gels are prepared where x, y and z are concentrations of NGs, PEGDGE and the PEGDGE molecular weight, respectively. The hydrogel compositions and nano-structural homogeneity of the NGs have strong impact on the enhancement of mechanical properties which enables property tuning. Based on this design, a highly compressive PEG-based nanocomposite hydrogel (NG-13-PEG-20-6000) exhibits a compressive stress of 24.2 MPa, compressive fracture strain greater than 98% and a fracture energy density as high as 1.88 MJ m-3. The tensile fracture strain is 230%. This is amongst one of the most compressive PEG-based hydrogels reported to-date. Our chemically crosslinked gels are resilient and show highly recoverable dissipative energy. The cytotoxicity test shows that human nucleus pulposus (NP) cells remained viable after 8 days of culture time. The overall results highlight their potential for applications as replacements for intervertebral discs or articular cartilages.
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Affiliation(s)
- Nam T Nguyen
- School of Materials, University of Manchester, Manchester, M13 9PL, UK.
| | - Amir H Milani
- School of Materials, University of Manchester, Manchester, M13 9PL, UK.
| | - James Jennings
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Daman J Adlam
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Anthony J Freemont
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Judith A Hoyland
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK and NIHR Manchester Biomedical Research Centre, Manchester University NHS foundation Trust, Manchester Academic Health Science Centre, M13 9WL, UK
| | - Brian R Saunders
- School of Materials, University of Manchester, Manchester, M13 9PL, UK.
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8
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Shanks HR, Zhu M, Milani AH, Turton J, Haigh S, Hodson NW, Adlam D, Hoyland J, Freemont T, Saunders BR. Core-shell-shell cytocompatible polymer dot-based particles with near-infrared emission and enhanced dispersion stability. Chem Commun (Camb) 2018; 54:9364-9367. [PMID: 30079412 DOI: 10.1039/c8cc04310h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polymer dots (PDs) are promising fluorescent probes for biomaterials applications. Here, novel cytocompatible composite PD particles have been synthesised with a core-shell-shell morphology. The particles show near-infrared emission, improved fluorescent brightness and enhanced colloidal stability compared to pure PDs. The particles also show non-radiative resonance energy transfer (NRET) with a model dye.
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Affiliation(s)
- Hannah R Shanks
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
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9
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Wang W, Lu D, Zhu M, Saunders JM, Milani AH, Armes SP, Saunders BR. Highly deformable hydrogels constructed by pH-triggered polyacid nanoparticle disassembly in aqueous dispersions. Soft Matter 2018; 14:3510-3520. [PMID: 29671461 DOI: 10.1039/c8sm00325d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Most hydrogels are prepared using small-molecule monomers but unfortunately this approach may not be feasible for certain biomaterial applications. Consequently, alternative gel construction strategies have been established, which include using covalent inter-linking of preformed gel particles, or microgels (MGs). For example, covalently interlinking pH-responsive MGs can produce hydrogels comprising doubly crosslinked microgels (DX MGs). We hypothesised that the deformability of such DX MGs was limited by the presence of intra-MG crosslinking. Thus, in this study we designed new nanoparticle (NP)-based gels based on pH-swellable NPs that are not internally crosslinked. Two polyacid NPs were synthesised containing methacrylic acid (MAA) and either ethyl acrylate (EA) or methyl methacrylate (MMA). The PMAA-EA and PMAA-MMA NPs were subsequently vinyl-functionalised using glycidyl methacrylate (GMA) prior to gel formation via free-radical crosslinking. The NPs mostly disassembled on raising the solution pH but some self-crosslinking was nevertheless evident. The gels constructed from the EA- and MMA-based NPs had greater breaking strains than a control DX MG. The effect of varying the solution pH during curing on the morphology and mechanical properties of gels prepared using PMAA-MMA-GMA NPs was studied and both remarkable deformability and excellent recovery were observed. The gels were strongly pH-responsive and had tensile breaking strains of up to 420% with a compressive strain-at-break of more than 93%. An optimised formulation produced the most deformable and stretchable gel yet constructed using NPs or MGs as the only building block.
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Affiliation(s)
- Wenkai Wang
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Dongdong Lu
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Mingning Zhu
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Jennifer M Saunders
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Amir H Milani
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Steven P Armes
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Brian R Saunders
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
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10
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Zhu M, Lu D, Wu S, Lian Q, Wang W, Milani AH, Cui Z, Nguyen NT, Chen M, Lyon LA, Adlam DJ, Freemont AJ, Hoyland JA, Saunders BR. Responsive Nanogel Probe for Ratiometric Fluorescent Sensing of pH and Strain in Hydrogels. ACS Macro Lett 2017; 6:1245-1250. [PMID: 35650778 DOI: 10.1021/acsmacrolett.7b00709] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study a new pH-responsive nanogel probe containing a complementary nonradiative resonance energy transfer (NRET) fluorophore pair is investigated and its ability to act as a versatile probe of network-related changes in three hydrogels demonstrated. Fluorescent sensing using NRET is a powerful method for studying relationships between Angstrom length-scale structure and macroscopic properties of soft matter. Unfortunately, inclusion of NRET fluorophores into such materials requires material-specific chemistry. Here, low concentrations of preformed nanogel probes were included into hydrogel hosts. Ratiometric photoluminescence (PL) data for the gels labeled with the nanogel probes enabled pH-triggered swelling and deswelling to be studied as well as Ca2+-triggered collapse and solute release. PL measurements during compression of a nanogel probe-labeled nanocomposite gel demonstrated mechanochromic behavior and strain sensing. The new nanogel probes have excellent potential for investigating the internal structures of gels and provide a versatile ratiometric fluorescent platform for studying pH and strain.
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Affiliation(s)
- Mingning Zhu
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Dongdong Lu
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Shanglin Wu
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Qing Lian
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Wenkai Wang
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Amir H. Milani
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Zhengxing Cui
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Nam T. Nguyen
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - Mu Chen
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
| | - L. Andrew Lyon
- Schmid
College of Science and Technology, Chapman University, Orange, California 92866, United States
| | - Daman J. Adlam
- Division
of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology,
Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, U.K
| | - Anthony J. Freemont
- Division
of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology,
Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, U.K
- NIHR
Manchester Musculoskeletal Biomedical Research Unit, Central Manchester
Foundation Trust, Manchester Academic Health Science Centre, Manchester, U.K
| | - Judith A. Hoyland
- Division
of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology,
Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, U.K
- NIHR
Manchester Musculoskeletal Biomedical Research Unit, Central Manchester
Foundation Trust, Manchester Academic Health Science Centre, Manchester, U.K
| | - Brian R. Saunders
- School
of Materials, University of Manchester, MSS Tower, Manchester M13 9PL, U.K
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11
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Yan J, Lian Q, Mokhtar MZ, Milani AH, Whittaker E, Hamilton B, O'Brien P, Nguyen NT, Saunders BR. Textured ZnO films from evaporation-triggered aggregation of nanocrystal dispersions and their use in solar cells. Phys Chem Chem Phys 2017; 19:27081-27089. [PMID: 28960011 DOI: 10.1039/c7cp05026g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Due to its high electron mobility, good stability and potential for low-temperature synthesis ZnO has received considerable attention for use in solar cells, photodetectors and sensors. Whilst there have been reports involving the formation ZnO films with porous morphologies the majority of those have involved elaborate or time-consuming preparation methods. In this study we investigate a simple new method for preparing textured porous ZnO (tp-ZnO) films. We used colloidal instability triggered by the evaporation of a volatile stabilising ligand during spin-coating of a ZnO nanocrystal (NC) dispersion to deposit crack-free tp-ZnO films. The porosity of the tp-ZnO films was 56% and they could be prepared using amine-based ligands with boiling points less than or equal to 78 °C. To demonstrate the ability to use the tp-ZnO films as electron acceptors they were infiltrated with poly(3-hexylthiophene) (P3HT) and solar cells prepared. The power conversion efficiencies of the tp-ZnO/P3HT devices reached values that were three times higher than a control bilayer ZnO/P3HT device prepared using a sol-gel derived ZnO film. Because our method used a low temperature treatment and ZnO films are used in a wide variety of third-generation solar cells, the new tp-ZnO films introduced here may offer a low cost method for improving the efficiency of other solar cells.
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Affiliation(s)
- Junfeng Yan
- School of Materials, MSS Tower, The University of Manchester, Manchester, M13 9PL, UK.
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12
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Wang W, Milani AH, Cui Z, Zhu M, Saunders BR. Pickering Emulsions Stabilized by pH-Responsive Microgels and Their Scalable Transformation to Robust Submicrometer Colloidoisomes with Selective Permeability. Langmuir 2017; 33:8192-8200. [PMID: 28749692 DOI: 10.1021/acs.langmuir.7b01618] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Colloidosomes are micrometer-sized hollow particles that have shells consisting of coagulated or fused colloid particles. While many large colloidosomes with sizes well above 1.0 μm have been prepared, there are fewer examples of submicrometer colloidosomes. Here, we establish a simple emulsion templating-based method for the preparation of robust submicrometer pH-responsive microgel colloidosomes. The colloidosomes are constructed from microgel particles based on ethyl acrylate and methacrylic acid with peripheral vinyl groups. The pH-responsive microgels acted as both a Pickering emulsion stabilizer and macro-cross-linker. The emulsion formation studies showed that the minimum droplet diameter was reached when the microgel particles were partially swollen. Microgel colloidosomes were prepared by covalently interlinking the microgels adsorbed at the oil-water interface using thermal free-radical coupling. The colloidosomes were prepared using a standard high-shear mixer with two different rotor sizes that corresponded to high shear (HS) and very high shear (VHS) mixing conditions. The latter enabled the construction of submicrometer pH-responsive microgel-colloidosomes on the gram scale. The colloidosomes swelled strongly when the pH increased to above 6.0. The colloidosomes were robust and showed no evidence of colloidosome breakup at high pH. The effect of solute size on shell permeation was studied using a range of FITC-dextran polymers, and size-selective permeation occurred. The average pore size of the VHS microgel-colloidosomes was estimated to be between 6.6 and 9.0 nm at pH 6.2. The microgel-colloidosome properties suggest that they have the potential for future applications in cosmetics, photonics, and delivery.
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Affiliation(s)
- Wenkai Wang
- Polymers and Composites Group, School of Materials, The University of Manchester , MSS Tower, Manchester M13 9PL, U.K
| | - Amir H Milani
- Polymers and Composites Group, School of Materials, The University of Manchester , MSS Tower, Manchester M13 9PL, U.K
| | - Zhengxing Cui
- Polymers and Composites Group, School of Materials, The University of Manchester , MSS Tower, Manchester M13 9PL, U.K
| | - Mingning Zhu
- Polymers and Composites Group, School of Materials, The University of Manchester , MSS Tower, Manchester M13 9PL, U.K
| | - Brian R Saunders
- Polymers and Composites Group, School of Materials, The University of Manchester , MSS Tower, Manchester M13 9PL, U.K
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Obeng M, Milani AH, Musa MS, Cui Z, Fielding LA, Farrand L, Goulding M, Saunders BR. Self-assembly of poly(lauryl methacrylate)-b-poly(benzyl methacrylate) nano-objects synthesised by ATRP and their temperature-responsive dispersion properties. Soft Matter 2017; 13:2228-2238. [PMID: 28252143 DOI: 10.1039/c6sm02656g] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Self-assembling poly(lauryl methacrylate)-b-poly(benzyl methacrylate) (PLMAx-PBzMAy) diblock copolymers were synthesised for the first time using solution atom transfer radical polymerisation (ATRP). The PLMA degree of polymerisation (x) was fixed at 14 and the PBzMA degree of polymerisation (y) was varied from 34 to 74. Post-polymerisation transfer of this new series of diblock copolymers from chloroform into n-dodecane (a poor solvent for PBzMA) resulted in self-assembly of polymeric nano-objects. The morphologies for the latter (spheres, worms and vesicles) were controlled by y. The observed morphologies generally agreed with those reported for related PLMAx-PBzMAy diblock copolymers (x ≥ 16) prepared by polymerisation induced self-assembly (PISA) via reversible addition-fragmentation chain transfer (RAFT) polymerisation (Fielding et al., J. Am. Chem. Soc., 2014, 136, 5790). However, a number of differences were observed such as de-gelation behaviour and the phase boundary positions compared to those expected from Fielding et al. Variable-temperature dynamic light scattering studies for the PLMA14-PBzMA34 spheres revealed that the aggregation number was unaffected by a temperature increase over the range of 20-90 °C, which differed markedly from the behaviour observed for PLMA14-PBzMA64 worms. This difference is a new observation with mechanistic importance for the worm-to-sphere breakdown mechanism. We show that concentrated PLMA14-PBzMAy dispersions (20% w/w) in n-dodecane can be prepared using post-polymerisation transfer. The dispersion with a mixed spherical and worm-like copolymer phase exhibited reversible de-gelation when heated. Surprisingly, the dispersions containing only the worm phase remained as gels (which were white) at temperatures up to 90 °C. Our new ATRP approach for preparing temperature-responsive non-aqueous nano-object dispersions presented here decoupled chain growth and self-assembly and will apply to other copolymer dispersions.
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Affiliation(s)
- Melody Obeng
- School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Amir H Milani
- School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Muhamad S Musa
- School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Zhengxing Cui
- School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Lee A Fielding
- School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Louise Farrand
- Merck Chemicals Ltd, Chilworth Technical Centre, University Parkway, Southampton, SO16 7QD, UK
| | - Mark Goulding
- Merck Chemicals Ltd, Chilworth Technical Centre, University Parkway, Southampton, SO16 7QD, UK
| | - Brian R Saunders
- School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
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Milani AH, Saunders JM, Nguyen NT, Ratcliffe LPD, Adlam DJ, Freemont AJ, Hoyland JA, Armes SP, Saunders BR. Synthesis of polyacid nanogels: pH-responsive sub-100 nm particles for functionalisation and fluorescent hydrogel assembly. Soft Matter 2017; 13:1554-1560. [PMID: 28120992 DOI: 10.1039/c6sm02713j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nanogels are crosslinked polymer particles with a swollen size between 1 and 100 nm. They are of major interest for advanced surface coatings, drug delivery, diagnostics and biomaterials. Synthesising polyacid nanogels that show triggered swelling using a scalable approach is a key objective of polymer colloid chemistry. Inspired by the ability of polar surfaces to enhance nanoparticle stabilisation, we report the first examples of pH-responsive polyacid nanogels containing high -COOH contents prepared by a simple, scalable, aqueous method. To demonstrate their functionalisation potential, glycidyl methacrylate was reacted with the -COOH chemical handles and the nanogels were converted to macro-crosslinkers. The concentrated (functionalised) nanogel dispersions retained their pH-responsiveness, were shear-thinning and formed physical gels at pH 7.4. The nanogels were covalently interlinked via free-radical coupling at 37 °C to form transparent, ductile, hydrogels. Mixing of the functionalised nanogels with polymer dots enabled covalent assembly of fluorescent hydrogels.
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Affiliation(s)
- Amir H Milani
- School of Materials, University of Manchester, Manchester, M13 9PL, UK.
| | | | - Nam T Nguyen
- School of Materials, University of Manchester, Manchester, M13 9PL, UK.
| | - Liam P D Ratcliffe
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Daman J Adlam
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Anthony J Freemont
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Judith A Hoyland
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, UK and NIHR Manchester Musculoskeletal Biomedical Research Unit, Manchester Academic Health Science Centre, Manchester, UK
| | - Steven P Armes
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Brian R Saunders
- School of Materials, University of Manchester, Manchester, M13 9PL, UK.
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Musa MS, Milani AH, Shaw P, Simpson G, Lovell PA, Eaves E, Hodson N, Saunders BR. Tuning the modulus of nanostructured ionomer films of core-shell nanoparticles based on poly(n-butyl acrylate). Soft Matter 2016; 12:8112-8123. [PMID: 27722747 DOI: 10.1039/c6sm01563h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study we investigate the structure-mechanical property relationships for nanostructured ionomer films containing ionically crosslinked core-shell polymer nanoparticles based on poly(n-butyl acrylate) (PBA). Whilst nanostructured ionomer films of core-shell nanoparticles have been previously shown to have good ductility [Soft Matter, 2014, 10, 4725], the modulus values were modest. Here, we used BA as the primary monomer to construct core-shell nanoparticles that provided films containing nanostructured polymers with much higher glass transition temperature (Tg) values. The core-shell nanoparticles were synthesised using BA, acrylonitrile (AN), methacrylic acid (MAA) and 1,4-butanediol diacrylate (BDDA). Nanostructured ionomer films were prepared by casting aqueous core-shell nanoparticle dispersions in which the shell -COOH groups were neutralised with KOH and ZnO. The film mechanical properties were studied using dynamic mechanical analysis and tensile stress-strain measurements. The use of BA-based nanoparticles increased the Tg values to close to room temperature which caused a strong dependence of the film mechanical properties on the AN content and extent of neutralisation of the -COOH groups. The Young's modulus values for the films ranged from 1.0 to 86.0 MPa. The latter is the highest modulus reported for cast films of nanostructured ionomer films prepared from core-shell nanoparticles. The films had good ductility with strain-at-break values of at least 200%. The mechanical properties of the films were successfully modelled using the isostrain model. From comparison with an earlier butadiene-based system this study demonstrates that the nature of the primary monomer used to construct the nanoparticles can profoundly change the film mechanical properties. The aqueous nanoparticle dispersion approach used here provides a simple and versatile method to prepare high modulus elastomer films with tuneable mechanical properties.
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Affiliation(s)
- Muhamad S Musa
- Polymer Science and Technology Group, MSS Tower, School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Amir H Milani
- Polymer Science and Technology Group, MSS Tower, School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Peter Shaw
- Synthomer (UK) Ltd, Temple Fields, Harlow, Essex CM20 2BH, UK
| | - Gareth Simpson
- Synthomer (UK) Ltd, Temple Fields, Harlow, Essex CM20 2BH, UK
| | - Peter A Lovell
- Polymer Science and Technology Group, MSS Tower, School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Elizabeth Eaves
- Polymer Science and Technology Group, MSS Tower, School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
| | - Nigel Hodson
- BioAFM Facility, Stopford Building, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Brian R Saunders
- Polymer Science and Technology Group, MSS Tower, School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
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Milani AH, Bramhill J, Freemont AJ, Saunders BR. Swelling and mechanical properties of hydrogels composed of binary blends of inter-linked pH-responsive microgel particles. Soft Matter 2015; 11:2586-2595. [PMID: 25683792 DOI: 10.1039/c4sm02432j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We show that a new type of hydrogel can be prepared by covalently inter-linking binary blends of microgel (MG) particles and that the swelling ratio and modulus of the gels can be predicted from their composition. In previous work we established that physical gels of glycidyl methacrylate (GMA) functionalised poly(methyl methacrylate-co-methacrylic acid-co-ethyleneglycol dimethacrylate) microgel particles (GMA-MG) could be covalently inter-linked to give hydrogels, termed doubly crosslinked microgels, DX MGs. We build on this concept here by investigating the properties of DX MGs containing binary blends of GMA-MG particles and glycidyl oligo(ether ester) acrylate-functionalised microgel particles (GOE-MG). These new hydrogels were assembled by inter-linking nanoscale MG building blocks in the absence of small molecule monomers or crosslinkers. The volume fraction of GMA-MG particles used to prepare the GOE-GMA DX MGs was systematically varied. Rheology data showed that inclusion of GMA-MG and GOE-MG within the GOE-GMA DX MGs increased the modulus and yield strain, respectively, compared to the values measured for the respective physical gels. The data for the covalent GOE-GMA DX MG gels showed that the ductility increased with increasing GOE-MG content. GOE provided covalent inter-linking of the MG particles and also acted as a lubricant between particles due to its low Tg. By demonstrating compositionally determined swelling and mechanical properties for DX MG gels prepared using binary blends of MG particles, this study introduces a new, widely applicable, hydrogel construction assembly concept that is not available for conventional hydrogels.
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Affiliation(s)
- Amir H Milani
- Polymer, Science Research Group, School of Materials, University of Manchester, Grosvenor Street, Manchester, M13 9PL, UK
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Mispelon A, Yan J, Milani AH, Chen M, Wang W, O'Brien P, Saunders BR. Effects of added thiol ligand structure on aggregation of non-aqueous ZnO dispersions and morphology of spin-coated films. RSC Adv 2015. [DOI: 10.1039/c4ra15013a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The structure of bidentate thiol ligands controls dispersion aggregation and enables spin coating of ZnO films with enhanced light scattering.
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Affiliation(s)
- Aloïs Mispelon
- Polymer Science and Technology Group
- School of Materials
- The University of Manchester
- Manchester
- UK
| | - Junfeng Yan
- Polymer Science and Technology Group
- School of Materials
- The University of Manchester
- Manchester
- UK
| | - Amir H. Milani
- Polymer Science and Technology Group
- School of Materials
- The University of Manchester
- Manchester
- UK
| | - Mu Chen
- Polymer Science and Technology Group
- School of Materials
- The University of Manchester
- Manchester
- UK
| | - Wenkai Wang
- Polymer Science and Technology Group
- School of Materials
- The University of Manchester
- Manchester
- UK
| | - Paul O'Brien
- Polymer Science and Technology Group
- School of Materials
- The University of Manchester
- Manchester
- UK
| | - Brian R. Saunders
- Polymer Science and Technology Group
- School of Materials
- The University of Manchester
- Manchester
- UK
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18
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Cui Z, Milani AH, Greensmith PJ, Yan J, Adlam DJ, Hoyland JA, Kinloch IA, Freemont AJ, Saunders BR. A study of physical and covalent hydrogels containing pH-responsive microgel particles and graphene oxide. Langmuir 2014; 30:13384-13393. [PMID: 25313805 DOI: 10.1021/la5032015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this study we mixed low concentrations of graphene oxide (GO) with microgel (MG) particles and formed composite doubly cross-linked microgels (DX MG/GO) gels. The MG particles comprised poly(ethyl acrylate-co-methacrylic acid-co-1,4-butanediol diacrylate) with pendant glycidyl methacrylate units. The MG/GO mixed dispersions formed physical gels of singly cross-linked MGs (termed SX MG/GO), which were subsequently heated to produce DX MG/GO gels by free-radical reaction. The influence of the GO concentration on the mechanical properties of the SX MG/GO and DX MG/GO gels was investigated using dynamic rheology and static compression measurements. The SX MG/GO physical gels were injectable and moldable. The moduli for the DX MG/GO gels increased by a factor of 4-6 when only ca. 1.0 wt % of GO was included. The isostrain model was used to describe the variation of modulus with DX MG/GO composition. Inclusion of GO dramatically altered the stress dissipation and yielding mechanisms for the gels. GO acted as a high surface area, high modulus filler and played an increasing role in load distribution as the GO concentration increased. It is proposed that MG domains were dispersed within a percolated GO network. Comparison of the modulus data with those published for GO-free DX MGs showed that inclusion of GO provided an unprecedented rate of modulus increase with network volume fraction for this family of colloid gels. Furthermore, the DX MG/GO gels were biocompatible and the results imply that there may be future applications of these new systems as injectable load supporting gels for soft tissue repair.
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Affiliation(s)
- Zhengxing Cui
- School of Materials, The University of Manchester , Grosvenor Street, Manchester, M1 7HS, United Kingdom
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Thaiboonrod S, Milani AH, Saunders BR. Doubly crosslinked poly(vinyl amine) microgels: hydrogels of covalently inter-linked cationic microgel particles. J Mater Chem B 2014; 2:110-119. [DOI: 10.1039/c3tb21579b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Milani AH, Freemont AJ, Hoyland JA, Adlam DJ, Saunders BR. Injectable Doubly Cross-Linked Microgels for Improving the Mechanical Properties of Degenerated Intervertebral Discs. Biomacromolecules 2012; 13:2793-801. [DOI: 10.1021/bm3007727] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Amir H. Milani
- Biomaterials Research Group,
Manchester Materials Science Centre, School of Materials, University of Manchester, Grosvenor Street, Manchester,
M13 9PL United Kingdom
| | - Anthony J. Freemont
- Regenerative Medicine, Developmental
Biomedicine Research Group, School of Medicine, Stopford Building, University of Manchester, Oxford Road, Manchester,
M13 9PT United Kingdom
| | - Judith A. Hoyland
- Regenerative Medicine, Developmental
Biomedicine Research Group, School of Medicine, Stopford Building, University of Manchester, Oxford Road, Manchester,
M13 9PT United Kingdom
| | - Daman J. Adlam
- Regenerative Medicine, Developmental
Biomedicine Research Group, School of Medicine, Stopford Building, University of Manchester, Oxford Road, Manchester,
M13 9PT United Kingdom
| | - Brian R. Saunders
- Biomaterials Research Group,
Manchester Materials Science Centre, School of Materials, University of Manchester, Grosvenor Street, Manchester,
M13 9PL United Kingdom
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