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Munne PM, Martikainen L, Räty I, Bertula K, Nonappa, Ruuska J, Ala-Hongisto H, Peura A, Hollmann B, Euro L, Yavuz K, Patrikainen L, Salmela M, Pokki J, Kivento M, Väänänen J, Suomi T, Nevalaita L, Mutka M, Kovanen P, Leidenius M, Meretoja T, Hukkinen K, Monni O, Pouwels J, Sahu B, Mattson J, Joensuu H, Heikkilä P, Elo LL, Metcalfe C, Junttila MR, Ikkala O, Klefström J. Compressive stress-mediated p38 activation required for ERα + phenotype in breast cancer. Nat Commun 2021; 12:6967. [PMID: 34845227 PMCID: PMC8630031 DOI: 10.1038/s41467-021-27220-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/04/2021] [Indexed: 01/01/2023] Open
Abstract
Breast cancer is now globally the most frequent cancer and leading cause of women's death. Two thirds of breast cancers express the luminal estrogen receptor-positive (ERα + ) phenotype that is initially responsive to antihormonal therapies, but drug resistance emerges. A major barrier to the understanding of the ERα-pathway biology and therapeutic discoveries is the restricted repertoire of luminal ERα + breast cancer models. The ERα + phenotype is not stable in cultured cells for reasons not fully understood. We examine 400 patient-derived breast epithelial and breast cancer explant cultures (PDECs) grown in various three-dimensional matrix scaffolds, finding that ERα is primarily regulated by the matrix stiffness. Matrix stiffness upregulates the ERα signaling via stress-mediated p38 activation and H3K27me3-mediated epigenetic regulation. The finding that the matrix stiffness is a central cue to the ERα phenotype reveals a mechanobiological component in breast tissue hormonal signaling and enables the development of novel therapeutic interventions. Subject terms: ER-positive (ER + ), breast cancer, ex vivo model, preclinical model, PDEC, stiffness, p38 SAPK.
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Affiliation(s)
- Pauliina M Munne
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Lahja Martikainen
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, PO Box, 15100, FI-00076, Espoo, Finland
| | - Iiris Räty
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Kia Bertula
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, PO Box, 15100, FI-00076, Espoo, Finland
| | - Nonappa
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, PO Box, 15100, FI-00076, Espoo, Finland
- Department of Bioproducts and Biosystems, Aalto University School of Chemical Engineering, Espoo, Finland
| | - Janika Ruuska
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Hanna Ala-Hongisto
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Aino Peura
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Babette Hollmann
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Lilya Euro
- Research Program of Stem Cells and Metabolism, Biomedicum Helsinki, University of Helsinki, 00290, Helsinki, Finland
| | - Kerim Yavuz
- Applied Tumor Genomics Research Program, Enhancer Biology Laboratory, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Linda Patrikainen
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Maria Salmela
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Juho Pokki
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
| | - Mikko Kivento
- Applied Tumor Genomics Research Program, Faculty of Medicine, Oncogenomics Laboratory, University of Helsinki, Helsinki, Finland
| | - Juho Väänänen
- Applied Tumor Genomics Research Program, Faculty of Medicine, Oncogenomics Laboratory, University of Helsinki, Helsinki, Finland
| | - Tomi Suomi
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, FI-20520, Turku, Finland
| | - Liina Nevalaita
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Minna Mutka
- Department of Pathology, HUSLAB and Haartman Institute, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Panu Kovanen
- Department of Pathology, HUSLAB and Haartman Institute, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Marjut Leidenius
- Breast Surgery Unit, Helsinki University Central Hospital, Helsinki, Finland
| | - Tuomo Meretoja
- Breast Surgery Unit, Helsinki University Central Hospital, Helsinki, Finland
| | - Katja Hukkinen
- Department of Mammography, Helsinki University Central Hospital, Helsinki, Finland
| | - Outi Monni
- Applied Tumor Genomics Research Program, Faculty of Medicine, Oncogenomics Laboratory, University of Helsinki, Helsinki, Finland
| | - Jeroen Pouwels
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland
| | - Biswajyoti Sahu
- Applied Tumor Genomics Research Program, Enhancer Biology Laboratory, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Johanna Mattson
- Department of Oncology, University of Helsinki & Helsinki University Hospital, Helsinki, Finland
| | - Heikki Joensuu
- Department of Oncology, University of Helsinki & Helsinki University Hospital, Helsinki, Finland
| | - Päivi Heikkilä
- Department of Pathology, HUSLAB and Haartman Institute, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Laura L Elo
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, FI-20520, Turku, Finland
| | - Ciara Metcalfe
- Genentech Inc., 1 DNA Way, South San Francisco, CA, 94080, USA
| | | | - Olli Ikkala
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, PO Box, 15100, FI-00076, Espoo, Finland
- Department of Bioproducts and Biosystems, Aalto University School of Chemical Engineering, Espoo, Finland
| | - Juha Klefström
- Finnish Cancer Institute, FICAN South Helsinki University Hospital & Translational Cancer Medicine, Medical Faculty, University of Helsinki. Cancer Cell Circuitry Laboratory, PO Box 63 Haartmaninkatu 8, 00014 University of Helsinki, Helsinki, Finland.
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Munne PM, Martikainen L, Räty I, Bertula K, Nonappa N, Peura A, Mutka M, Leidenius M, Meretoja T, Kovanen P, Mattson J, Heikkila P, Joensuu H, Ikkala O, Klefstrom JT. Abstract 2966: Novel ex vivo model for ERα positive breast cancer. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-2966] [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: 11/16/2022]
Abstract
Abstract
Three-dimensional ex vivo cultures from patient-derived tumor tissue offer new opportunities for drug development and personalized treatment of cancer. However, one of the main challenges in establishing a tumor type faithful ex vivo tissue culture system is in optimization of biochemical and physical microenvironment to preserve desired phenotypic features. A collaboration with the Helsinki University Hospital enables us to receive live patient-derived breast cancer tissue samples from most breast cancer surgeries performed in the Southern Finland, typically samples arriving twice a week. Together with a group of materials scientists from Aalto Technical University we have explored seven different 3D culture matrices and defined their biomechanical properties and stiffness values with rheological measurements. Four investigated matrices preserved the luminal CK8+ cell phenotype of the luminal cancers they derived from, whereas rest of the matrices that included commonly used Matrigel and collagen scaffolds promoted a switch in the cell identity from luminal CK8+ to basal CK14+ phenotype. Furthermore, the genetic expression profiles examined with NGS corresponded to observed phenotypic switch. We noticed significant species-specific differences between mouse mammary and human breast samples in their morphology, phenotypic responses and ERα+ preservation to microenvironmental matrix stiffness. Furthermore, a combination of scaffold stiffness and composition of biochemical matrix constituency is required for long-term maintenance of ERα+ luminal tumour phenotype. Therefore, both physical properties and composition of the microenvironment need to be optimized for maintenance of breast tumor type specific phenotype and genetic profiles of ex vivo tumor explant cultures.
Citation Format: Pauliina M. Munne, Lahja Martikainen, Iiris Räty, Kia Bertula, Nonappa Nonappa, Aino Peura, Minna Mutka, Marjut Leidenius, Tuomo Meretoja, Panu Kovanen, Johanna Mattson, Paivi Heikkila, Heikki Joensuu, Olli Ikkala, Juha T. Klefstrom. Novel ex vivo model for ERα positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2966.
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Affiliation(s)
| | | | - Iiris Räty
- 1University of Helsinki, Helsinki, Finland
| | - Kia Bertula
- 2Aalto University School of Science, Helsinki, Finland
| | | | - Aino Peura
- 1University of Helsinki, Helsinki, Finland
| | - Minna Mutka
- 3Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | | | - Tuomo Meretoja
- 4Helsinki University Central Hospital, Helsinki, Finland
| | - Panu Kovanen
- 3Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Johanna Mattson
- 5Helsinki University Hospital & University of Helsinki, Helsinki, Finland
| | - Paivi Heikkila
- 3Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Heikki Joensuu
- 6Helsinki University Hospital & University of Helsinki, Helsinki, Finland
| | - Olli Ikkala
- 2Aalto University School of Science, Helsinki, Finland
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Özdemir Z, Šaman D, Bertula K, Lahtinen M, Bednárová L, Pazderková M, Rárová L, Wimmer Z. Rapid Self-Healing and Thixotropic Organogelation of Amphiphilic Oleanolic Acid-Spermine Conjugates. Langmuir 2021; 37:2693-2706. [PMID: 33595317 DOI: 10.1021/acs.langmuir.0c03335] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Natural and abundant plant triterpenoids are attractive starting materials for the synthesis of conformationally rigid and chiral building blocks for functional soft materials. Here, we report the rational design of three oleanolic acid-triazole-spermine conjugates, containing either one or two spermine units in the target molecules, using the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction. The resulting amphiphile-like molecules 2 and 3, bearing just one spermine unit in the respective molecules, self-assemble into highly entangled fibrous networks leading to gelation at a concentration as low as 0.5% in alcoholic solvents. Using step-strain rheological measurements, we show rapid self-recovery (up to 96% of the initial storage modulus) and sol ⇔ gel transition under several cycles. Interestingly, rheological flow curves reveal the thixotropic behavior of the gels. To the best of our knowledge, this kind of behavior was not shown in the literature before, neither for a triterpenoid nor for its derivatives. Conjugate 4, having a bolaamphiphile-like structure, was found to be a nongelator. Our results indicate that the position and number of spermine units alter the gelation properties, gel strength, and their self-assembly behavior. Preliminary cytotoxicity studies of the target compounds 2-4 in four human cancer cell lines suggest that the position and number of spermine units affect the biological activity. Our results also encourage exploring other triterpenoids and their derivatives as sustainable, renewable, and biologically active building blocks for multifunctional soft organic nanomaterials.
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Affiliation(s)
- Zulal Özdemir
- Department of Chemistry of Natural Compounds, University of Chemistry and Technology in Prague, Technická 5, 16028 Prague 6, Czech Republic
- Isotope Laboratory, Institute of Experimental Botany of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague 4, Czech Republic
| | - David Šaman
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 16610 Prague 6, Czech Republic
| | - Kia Bertula
- Department of Applied Physics, Aalto University, Puumiehenkuja 2, FI-02150 Espoo, Finland
| | - Manu Lahtinen
- Department of Chemistry, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - Lucie Bednárová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 16610 Prague 6, Czech Republic
| | - Markéta Pazderková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 16610 Prague 6, Czech Republic
- Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 12116 Prague 2, Czech Republic
| | - Lucie Rárová
- Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences, and Faculty of Science, Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic
| | - Zdeněk Wimmer
- Department of Chemistry of Natural Compounds, University of Chemistry and Technology in Prague, Technická 5, 16028 Prague 6, Czech Republic
- Isotope Laboratory, Institute of Experimental Botany of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague 4, Czech Republic
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Martikainen L, Bertula K, Turunen M, Ikkala O. Strain Stiffening and Negative Normal Force of Agarose Hydrogels. Macromolecules 2020; 53:9983-9992. [PMID: 33250522 PMCID: PMC7690039 DOI: 10.1021/acs.macromol.0c00601] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 03/16/2020] [Revised: 08/24/2020] [Indexed: 11/28/2022]
Abstract
Inspired by the specific strain stiffening and negative normal force phenomena in several biological networks, herein, we show strain stiffening and negative normal force in agarose hydrogels. We use both pre-strain and strain amplitude sweep protocols in dynamic rheological measurements where the gel slip was suppressed by the in situ gelation in the cross-hatched parallel plate rheometer geometry. Within the stiffening region, we show the scaling relation for the differential modulus K ∝ σ1, where σ is stress. The strain at the onset of stiffening is almost constant throughout the concentration range. The gels show negative apparent normal stress difference when sheared as a result of the gel contraction. The pore size of the hydrogel is large enough to allow water to move with respect to the network to balance the pressure difference caused by the hoop stress. The rheological analysis together with scanning electron microscopy suggests that the agarose gels can be described using subisostatic athermal network models where the connectivity dictates the stiffening behavior. Therefore, the simple agarose gels appear to capture several of the viscoelastic properties, which were previously thought to be characteristic to biological protein macromolecules.
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Affiliation(s)
- Lahja Martikainen
- Department
of Applied Physics, Molecular Materials Group, Aalto University School of Science, FI-00076 Espoo, Finland
| | - Kia Bertula
- Department
of Applied Physics, Molecular Materials Group, Aalto University School of Science, FI-00076 Espoo, Finland
| | - Matti Turunen
- Department
of Applied Physics, Molecular Materials Group, Aalto University School of Science, FI-00076 Espoo, Finland
| | - Olli Ikkala
- Department
of Applied Physics, Molecular Materials Group, Aalto University School of Science, FI-00076 Espoo, Finland
- Department
of Bioproducts and Biosystems, Aalto University
School of Chemical Engineering, FI-00076 Espoo, Finland
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Kolari K, Bulatov E, Tatikonda R, Bertula K, Kalenius E, Haukka M. Self-healing, luminescent metallogelation driven by synergistic metallophilic and fluorine-fluorine interactions. Soft Matter 2020; 16:2795-2802. [PMID: 32104828 DOI: 10.1039/c9sm02186h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Square planar platinum(ii) complexes are attractive building blocks for multifunctional soft materials due to their unique optoelectronic properties. However, for soft materials derived from synthetically simple discrete metal complexes, achieving a combination of optical properties, thermoresponsiveness and excellent mechanical properties is a major challenge. Here, we report the rapid self-recovery of luminescent metallogels derived from platinum(ii) complexes of perfluoroalkyl and alkyl derivatives of terpyridine ligands. Using single crystal X-ray diffraction studies, we show that the presence of synergistic platinum-platinum (PtPt) metallopolymerization and fluorine-fluorine (FF) interactions are the major driving forces in achieving hierarchical superstructures. The resulting bright red gels showed the presence of highly entangled three-dimensional networks and helical nanofibres with both (P and M) handedness. The gels recover up to 87% of their original storage modulus even after several cycles under oscillatory step-strain rheological measurements showing rapid self-healing. The luminescence properties, along with thermo- and mechanoresponsive gelation, provide the potential to utilize synthetically simple discrete complexes in advanced optical materials.
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Affiliation(s)
- Kalle Kolari
- Department of Chemistry, University of Jyväskylä, P. O. Box 35, FI-40014 Jyväskylä, Finland.
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Hörenz C, Bertula K, Tiainen T, Hietala S, Hynninen V, Ikkala O. UV-Triggered On-Demand Temperature-Responsive Reversible and Irreversible Gelation of Cellulose Nanocrystals. Biomacromolecules 2020; 21:830-838. [PMID: 31940433 PMCID: PMC7735667 DOI: 10.1021/acs.biomac.9b01519] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/15/2020] [Indexed: 11/29/2022]
Abstract
We show ionically cross-linked, temperature-responsive reversible or irreversible hydrogels of anionic cellulose nanocrystals (CNCs) and methacrylate terpolymers by mixing them homogeneously in the initially charge-neutral state of the polymer, which was subsequently switched to be cationic by cleaving side groups by UV irradiation. The polymer is a random terpolymer poly(di(ethylene glycol) methyl ether methacrylate)-rnd-poly(oligo(ethylene glycol) methyl ether methacrylate)-rnd-poly(2-((2-nitrobenzyl)oxycarbonyl)aminoethyl methacrylate), that is, PDEGMA-rnd-POEGMA-rnd-PNBOCAEMA. The PDEGMA and POEGMA repeating units lead to a lower critical solution temperature (LCST) behavior. Initially, homogeneous aqueous mixtures are obtained with CNCs, and no gelation is observed even upon heating to 60 °C. However, upon UV irradiation, the NBOCAEMAs are transformed to cationic 2-aminoethyl methacrylate (AEMA) groups, as 2-nitrobenzaldehyde moieties are cleaved. The resulting mixtures of anionic CNC and cationic PDEGMA-rnd-POEGMA-rnd-PAEMA show gelation for sufficiently high polymer fractions upon heating to 60 °C due to the interplay of ionic interactions and LCST. For short heating times, the gelation is thermoreversible, whereas for long enough heating times, irreversible gels can be obtained, indicating importance of kinetic aspects. The ionic nature of the cross-linking is directly shown by adding NaCl, which leads to gel melting. In conclusion, the optical triggering of the polymer ionic interactions in combination with its LCST phase behavior allows a new way for ionic nanocellulose hydrogel assemblies.
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Affiliation(s)
- Christoph Hörenz
- Department
of Applied Physics, Aalto University School
of Science, P. O. Box 15100, Espoo FI-00076, Finland
| | - Kia Bertula
- Department
of Applied Physics, Aalto University School
of Science, P. O. Box 15100, Espoo FI-00076, Finland
| | - Tony Tiainen
- Department
of Chemistry, University of Helsinki, P. O. Box 55, Helsinki FI-00014 HU, Finland
| | - Sami Hietala
- Department
of Chemistry, University of Helsinki, P. O. Box 55, Helsinki FI-00014 HU, Finland
| | - Ville Hynninen
- Department
of Applied Physics, Aalto University School
of Science, P. O. Box 15100, Espoo FI-00076, Finland
| | - Olli Ikkala
- Department
of Applied Physics, Aalto University School
of Science, P. O. Box 15100, Espoo FI-00076, Finland
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Abstract
Strain-stiffening is one of the characteristic properties of biological hydrogels and extracellular matrices, where the stiffness increases upon increased deformation. Whereas strain-stiffening is ubiquitous in protein-based materials, it has been less observed for polysaccharide and synthetic polymer gels. Here we show that agarose, that is, a common linear polysaccharide, forms helical fibrillar bundles upon cooling from aqueous solution. The hydrogels with these semiflexible fibrils show pronounced strain-stiffening. However, to reveal strain-stiffening, suppressing wall slippage turned as untrivial. Upon exploring different sample preparation techniques and rheological architectures, the cross-hatched parallel plate geometries and in situ gelation in the rheometer successfully prevented the slippage and resolved the strain-stiffening behavior. Combining with microscopy, we conclude that strain-stiffening is due to the semiflexible nature of the agarose fibrils and their geometrical connectivity, which is below the central-force isostatic critical connectivity. The biocompatibility and the observed strain-stiffening suggest the potential of agarose hydrogels in biomedical applications.
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Affiliation(s)
- Kia Bertula
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, P.O. Box 15100, FI-00076, Espoo, Finland
| | - Lahja Martikainen
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, P.O. Box 15100, FI-00076, Espoo, Finland
| | - Pauliina Munne
- Research Programs Unit/Translational Cancer Medicine Program and HiLIFE, University of Helsinki, P.O. Box 63, FI-00014, Helsinki, Finland
| | - Sami Hietala
- Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014, HU, Helsinki, Finland
| | - Juha Klefström
- Research Programs Unit/Translational Cancer Medicine Program and HiLIFE, University of Helsinki, P.O. Box 63, FI-00014, Helsinki, Finland
| | - Olli Ikkala
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, P.O. Box 15100, FI-00076, Espoo, Finland
- Department of Bioproducts and Biosystems, Aalto University School of Chemical Engineering, P.O.
Box 15100, FI-00076, Espoo, Finland
| | - Nonappa
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, P.O. Box 15100, FI-00076, Espoo, Finland
- Department of Bioproducts and Biosystems, Aalto University School of Chemical Engineering, P.O.
Box 15100, FI-00076, Espoo, Finland
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Tatikonda R, Bertula K, Nonappa, Hietala S, Rissanen K, Haukka M. Bipyridine based metallogels: an unprecedented difference in photochemical and chemical reduction in the in situ nanoparticle formation. Dalton Trans 2018; 46:2793-2802. [PMID: 28174774 DOI: 10.1039/c6dt04253h] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Metal co-ordination induced supramolecular gelation of low molecular weight organic ligands is a rapidly expanding area of research due to the potential in creating hierarchically self-assembled multi-stimuli responsive materials. In this context, structurally simple O-methylpyridine derivatives of 4,4'-dihydroxy-2,2'-bipyridine ligands are reported. Upon complexation with Ag(i) ions in aqueous dimethyl sulfoxide (DMSO) solutions the ligands spontaneously form metallosupramolecular gels at concentrations as low as 0.6 w/v%. The metal ions induce the self-assembly of three dimensional (3D) fibrillar networks followed by the spontaneous in situ reduction of the Ag-centers to silver nanoparticles (AgNPs) when exposed to daylight. Significant size and morphological differences of the AgNP's was observed between the standard chemical and photochemical reduction of the metallogels. The gelation ability, the nanoparticle formation and rheological properties were found to be depend on the ligand structure, while the strength of the gels is affected by the water content of the gels.
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Affiliation(s)
- Rajendhraprasad Tatikonda
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P. O. Box 35, FI-40014, Jyväskylä, Finland.
| | - Kia Bertula
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, Puumiehenkuja 2, FI-02150, Espoo, Finland
| | - Nonappa
- Department of Applied Physics, Molecular Materials Group, Aalto University School of Science, Puumiehenkuja 2, FI-02150, Espoo, Finland
| | - Sami Hietala
- Department of Chemistry, University of Helsinki, P. O. Box 55, FI-00014, Helsinki, Finland
| | - Kari Rissanen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P. O. Box 35, FI-40014, Jyväskylä, Finland.
| | - Matti Haukka
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P. O. Box 35, FI-40014, Jyväskylä, Finland.
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Bertula K, Nonappa, Myllymäki TT, Yang H, Zhu X, Ikkala O. Hierarchical self-assembly from nanometric micelles to colloidal spherical superstructures. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.08.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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