51
|
Furusawa K, Sato S, Masumoto JI, Hanazaki Y, Maki Y, Dobashi T, Yamamoto T, Fukui A, Sasaki N. Studies on the Formation Mechanism and the Structure of the Anisotropic Collagen Gel Prepared by Dialysis-Induced Anisotropic Gelation. Biomacromolecules 2011; 13:29-39. [DOI: 10.1021/bm200869p] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Kazuya Furusawa
- Faculty of Advanced Life Science, Hokkaido University, Kita-ku Kita 10 Nishi 8, Sapporo,
Hokkaido, Japan
| | - Shoichi Sato
- Transdisciplinary
Life Science
Course, Graduate School of Life Science, Hokkaido University, Kita-ku Kita 10 Nishi 8, Sapporo, Hokkaido, Japan
| | - Jyun-ichi Masumoto
- Transdisciplinary
Life Science
Course, Graduate School of Life Science, Hokkaido University, Kita-ku Kita 10 Nishi 8, Sapporo, Hokkaido, Japan
| | - Yohei Hanazaki
- Transdisciplinary
Life Science
Course, Graduate School of Life Science, Hokkaido University, Kita-ku Kita 10 Nishi 8, Sapporo, Hokkaido, Japan
| | - Yasuyuki Maki
- Department of Chemistry
and Chemical Biology, Graduate School of Engineering, Gunma University, Tenjincho 1-5-1, Kiryu, Gunma, Japan
| | - Toshiaki Dobashi
- Department of Chemistry
and Chemical Biology, Graduate School of Engineering, Gunma University, Tenjincho 1-5-1, Kiryu, Gunma, Japan
| | - Takao Yamamoto
- Department of Chemistry
and Chemical Biology, Graduate School of Engineering, Gunma University, Tenjincho 1-5-1, Kiryu, Gunma, Japan
| | - Akimasa Fukui
- Faculty of Advanced Life Science, Hokkaido University, Kita-ku Kita 10 Nishi 8, Sapporo,
Hokkaido, Japan
| | - Naoki Sasaki
- Faculty of Advanced Life Science, Hokkaido University, Kita-ku Kita 10 Nishi 8, Sapporo,
Hokkaido, Japan
| |
Collapse
|
52
|
Helary C, Rodriguez-Sanchez B, Rodrigues-Sanchez B, Vigier S, Giraud Guill MM. Dense fibrillar collagen matrices to analyse extracellular matrix receptor function. ACTA ACUST UNITED AC 2011; 60:7-14. [PMID: 22153897 DOI: 10.1016/j.patbio.2011.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 08/30/2011] [Indexed: 01/13/2023]
Abstract
AIM The goal of this study was to understand whether dense fibrillar collagen matrices, with a hierarchical structure resembling native collagen matrices, could be useful to study collagen receptor function, in a more physiological context. The receptor analysed here was integrin α11β1, already shown to be involved in cell attachment and migration on collagen-coated plastic, and also in contraction of loose fibrillar collagen hydrogels. MATERIALS AND METHODS Collagen matrices prepared here corresponded to dense fibrillar hydrogels concentrated at 5mg/ml. The behaviour of α11β1 deficient fibroblasts seeded on these concentrated matrices was assessed in terms of adhesion, morphology and migration, then compared to that observed on classical hydrogels at 1mg/ml, corresponding to loose collagen matrices. RESULTS Short-term attachment assays showed disturbed interactions between α11β1 deficient cells and collagen matrices in a concentration-dependent manner. Long-term assays revealed reduced cell spreading of alpha 11(-/-) cells on the dense collagen matrices, associated with a disturbed cytoskeleton network. Moreover, anoikis was observed when alpha 11(-/-) cells were seeded on 5mg/ml matrices, and not on looser 1mg/ml matrices. In scratch wound in vitro assays, carried out with cells on 5mg/ml fibrillar collagen matrices, alpha 11(-/-) cells migrated much better than their wild-type counterparts. In contrast, no significant difference was observed between wild and knock-out cells seeded on plastic. CONCLUSIONS The present study demonstrates the validity of in vivo-like dense fibrillar collagen matrices to evaluate cell receptor functions more significantly than with 2D cell cultures or loose hydrogels.
Collapse
Affiliation(s)
- C Helary
- CNRS-UMR 7574, laboratoire chimie de la matière condensée, University Pierre and Marie Curie-Paris 6, école pratique des Hautes-Études, 4, place Jussieu, 75005 Paris, France.
| | | | | | | | | |
Collapse
|
53
|
Marchal A, Steunou N, Mosser G, Coradin T, Maquet J, Livage J. Assembly of Decavanadate Polyanions by Collagen Helices: Synthesis of an Hybrid Inorganic-Bioorganic Mmaterial. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-0972-aa05-04-qq02-04] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractVanadium oxide-collagen hybrid nanocomposites were prepared by adding a V2O5 sol to a dilute collagen solution. 51V MAS NMR spectroscopy shows that the inorganic phase is composed of the decavanadate [H2V10O28]4− polyanion and V2O5 ribbon-like particles. The broadening of the 51V signals and the absence of Bragg peaks in the XRD pattern suggest a strong disorder concerning the organization of the V2O5 particles and of the decavanadate species in the composites. Analogous hybrid nanocomposites were obtained with a solution that contains only the decavanadate species, showing that the cohesion in the hydrid material results mainly from electrostatic interactions between decavanadate [H2V10O28]4− polyanions and positively-charged collagen helices.
Collapse
|
54
|
Deniset-Besseau A, De Sa Peixoto P, Mosser G, Schanne-Klein MC. Nonlinear optical imaging of lyotropic cholesteric liquid crystals. OPTICS EXPRESS 2010; 18:1113-21. [PMID: 20173934 DOI: 10.1364/oe.18.001113] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We use nonlinear optical microscopy combining Second Harmonic Generation (SHG) microscopy and Two-Photon Excited Fluorescence (2PEF) signals to characterize collagen lyotropic liquid crystals. We show that SHG signals provide highly contrasted images of the three-dimensional texture of cholesteric patterns with submicrometer lateral resolution. Moreover, simultaneous recording of the 2PEF signal enables in situ quantitative mapping of the molecular concentration and its correlation with the observed textures. We apply this technique to the characterization of biomimetic textures obtained in concentrated collagen liquid solutions. We successfully image biologically relevant organizations that are similar to the collagen organization found as a stabilized state in compact bones.
Collapse
Affiliation(s)
- Ariane Deniset-Besseau
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM U696, Palaiseau, France
| | | | | | | |
Collapse
|
55
|
Kirkwood JE, Fuller GG. Liquid crystalline collagen: a self-assembled morphology for the orientation of mammalian cells. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3200-3206. [PMID: 19437784 DOI: 10.1021/la803736x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report the creation of collagen films having a cholesteric banding structure with an orientation that can be systematically controlled. The action of hydrodynamic flow and rapid desiccation was used to influence the orientation of collagen fibrils, producing a film with a twisted plywood architecture. Adult human fibroblasts cultured on these substrates orient in the direction of the flow deposition, and filopodia are extended onto individual bands. Atomic force microscopy reveals the assembly of 30 nm collagen fibrils into the uniform cholesteric collagen films with a periodic surface relief. The generation of collagen with a reticular, "basket-weave" morphology when using lower concentrations is also discussed.
Collapse
Affiliation(s)
- John E Kirkwood
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
| | | |
Collapse
|
56
|
Huang J, Cebe P, Kaplan DL. Hierarchical Assembly of Collagen-Like Peptidesin vitroProvides Structural Causes of Osteogenesis Imperfecta. Macromol Rapid Commun 2009; 30:336-44. [DOI: 10.1002/marc.200800591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 11/30/2008] [Accepted: 12/01/2008] [Indexed: 11/08/2022]
|
57
|
Starborg T, Lu Y, Meadows RS, Kadler KE, Holmes DF. Electron microscopy in cell-matrix research. Methods 2008; 45:53-64. [PMID: 18442705 DOI: 10.1016/j.ymeth.2008.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 01/30/2008] [Indexed: 10/22/2022] Open
Abstract
Tissue development in multicellular animals relies on the ability of cells to synthesise an extracellular matrix (ECM) containing spatially-organised fibrous assemblies, the most widespread of which is based on collagen fibrils whose length greatly exceeds that of individual cells. The importance of the correct regulation of fibril deposition is exemplified in diseases such as osteogenesis imperfecta (caused by mutations in collagen genes), fibrosis (caused by ectopic accumulation of collagen) and cardiovascular disease (which involves cells and macromolecules binding to collagen in the vessel wall). Much is known about the molecular biology of collagens but less is known about collagen fibril structure and how the fibrils are formed (fibrillogenesis). This is explained in part by the fact that the fibrils are non-crystalline, extensively cross-linked, and very large, which makes them refractory to study by conventional biochemical and high-resolution structure-determination techniques. Electron microscopy has become established as the method of choice for studying collagen fibril structure and assembly, and this article describes the electron microscope methods most often used.
Collapse
Affiliation(s)
- Tobias Starborg
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, UK
| | | | | | | | | |
Collapse
|
58
|
Cheng X, Gurkan UA, Dehen CJ, Tate MP, Hillhouse HW, Simpson GJ, Akkus O. An electrochemical fabrication process for the assembly of anisotropically oriented collagen bundles. Biomaterials 2008; 29:3278-88. [DOI: 10.1016/j.biomaterials.2008.04.028] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Accepted: 04/14/2008] [Indexed: 02/05/2023]
|
59
|
|
60
|
Crabb RAB, Hubel A. Influence of matrix processing on the optical and biomechanical properties of a corneal stroma equivalent. Tissue Eng Part A 2008; 14:173-82. [PMID: 18333815 DOI: 10.1089/ten.a.2007.0139] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Interest in developing tissue-engineered cornea has increased with the decrease in the supply of donor tissue; however, the high strength and transparency of the cornea present a challenge. Both the collagen processing and crosslinking methods were hypothesized to influence the optical and biomechanical properties of collagen matrices, while regular surface topography was hypothesized to align stromal fibroblasts. Improved transparency and strength were observed when soluble tropocollagen was added to the insoluble collagen and when glucose-mediated ultraviolet (UV) crosslinking as opposed to dehydrothermal crosslinking was used. The fraction of transmittance of the collagen films fabricated from insoluble collagen and soluble tropocollagen and glucose-mediated UV crosslinking was initially 0.91 +/- 0.02 and 0.98 +/- 0.01 for the smooth films and 0.90 +/- 0.02 and 0.97 +/- 0.02 for the microgrooved films at 400 and 700 nm and was comparable to that of the native cornea, while the relaxed modulus and ultimate tensile strength ranged from 0.9 to 9.4 MPa and from 0.7 to 4.1 MPa, respectively, over the 3 weeks of culture and were initially at or below the range of values for the native cornea. These collagen scaffolds were significantly stronger and more transparent than previous scaffolds, and aligned stromal fibroblasts were observed on microgrooved surfaces.
Collapse
Affiliation(s)
- Rachael A B Crabb
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | | |
Collapse
|
61
|
Giraud-Guille MM, Belamie E, Mosser G, Helary C, Gobeaux F, Vigier S. Liquid crystalline properties of type I collagen: Perspectives in tissue morphogenesis. CR CHIM 2008. [DOI: 10.1016/j.crci.2007.05.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
62
|
|
63
|
Gobeaux F, Mosser G, Anglo A, Panine P, Davidson P, Giraud-Guille MM, Belamie E. Fibrillogenesis in dense collagen solutions: a physicochemical study. J Mol Biol 2008; 376:1509-22. [PMID: 18234220 DOI: 10.1016/j.jmb.2007.12.047] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 12/06/2007] [Accepted: 12/19/2007] [Indexed: 11/19/2022]
Abstract
Fibrillogenesis, the formation of collagen fibrils, is a key factor in connective tissue morphogenesis. To understand to what extent cells influence this process, we systematically studied the physicochemistry of the self-assembly of type I collagen molecules into fibrils in vitro. We report that fibrillogenesis in solutions of type I collagen, in a high concentration range close to that of living tissues (40-300 mg/ml), yields strong gels over wide pH and ionic strength ranges. Structures of gels were described by combining microscopic observations (transmission electron microscopy) with small- and wide-angle X-ray scattering analysis, and the influence of concentration, pH, and ionic strength on the fibril size and organization was evaluated. The typical cross-striated pattern and the corresponding small-angle X-ray scattering 67-nm diffraction peaks were visible in all conditions in the pH 6 to pH 12 range. In reference conditions (pH 7.4, ionic strength=150 mM, 20 degrees C), collagen concentration greatly influences the overall macroscopic structure of the resultant fibrillar gels, as well as the morphology and structure of the fibrils themselves. At a given collagen concentration, increasing the ionic strength from 24 to 261 mM produces larger fibrils until the system becomes biphasic. We also show that fibrils can form in acidic medium (pH approximately 2.5) at very high collagen concentrations, beyond 150 mg/ml, which suggests a possible cholesteric-to-smectic phase transition. This set of data demonstrates how simple physicochemical parameters determine the molecular organization of collagen. Such an in vitro model allows us to study the intricate process of fibrillogenesis in conditions of molecular packing close to that which occurs in biological tissue morphogenesis.
Collapse
Affiliation(s)
- F Gobeaux
- Chimie de la Matière Condensée, UMR 7574 CNRS-Université Pierre et Marie Curie, ENSCP-Ecole Pratique des Hautes Etudes, 12 rue Cuvier, 75005 Paris, France
| | | | | | | | | | | | | |
Collapse
|
64
|
Crabb RA, Hubel A. Influence of Matrix Processing on the Optical and Biomechanical Properties of a Corneal Stroma Equivalent. ACTA ACUST UNITED AC 2008. [DOI: 10.1089/ten.2007.0139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
65
|
Starborg T, Lu Y, Kadler KE, Holmes DF. Electron microscopy of collagen fibril structure in vitro and in vivo including three-dimensional reconstruction. Methods Cell Biol 2008; 88:319-45. [PMID: 18617041 DOI: 10.1016/s0091-679x(08)00417-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tissue development in multicellular animals relies on the ability of cells to synthesize an extracellular matrix (ECM) containing spatially organized collagen fibrils, whose length greatly exceeds that of individual cells. The importance of the correct regulation of fibril deposition is exemplified in diseases such as osteogenesis imperfecta (caused by mutations in collagen genes), fibrosis (caused by ectopic accumulation of collagen), and cardiovascular disease (which involves cells and macromolecules binding to collagen in the vessel wall). Much is known about the molecular biology of collagens but less is known about collagen fibril structure and how the fibrils are formed (fibrillogenesis). This is explained in part by the fact that the fibrils are noncrystalline, extensively cross-linked, and very large, which makes them refractory to study by conventional biochemical and high-resolution structure-determination techniques. Electron microscopy has become established as the method of choice for studying collagen fibril structure and assembly. This article describes the electron microscopic methods most often used in studying collagen fibril assembly and structure.
Collapse
Affiliation(s)
- Tobias Starborg
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | | | | | | |
Collapse
|
66
|
Torbet J, Malbouyres M, Builles N, Justin V, Roulet M, Damour O, Oldberg A, Ruggiero F, Hulmes DJS. Orthogonal scaffold of magnetically aligned collagen lamellae for corneal stroma reconstruction. Biomaterials 2007; 28:4268-76. [PMID: 17618680 DOI: 10.1016/j.biomaterials.2007.05.024] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Accepted: 05/25/2007] [Indexed: 11/26/2022]
Abstract
The creation of 3D scaffolds that mimic the structure of physiological tissue required for normal cell function is a major bioengineering challenge. For corneal stroma reconstruction this necessitates the creation of a stroma-like scaffold consisting of a stack of orthogonally disposed sheets of aligned collagen fibrils. This study demonstrates that such a scaffold can be built up using magnetic alignment. By allowing neutralized acid-soluble type I collagen to gel in a horizontal magnetic field (7 T) and by combining a series of gelation-rotation-gelation cycles, a scaffold of orthogonal lamellae composed of aligned collagen fibrils has been formed. Although initially dilute, the gels can be concentrated without noticeable loss in orientation. The gels are translucent but their transparency can be greatly improved by the addition of proteoglycans to the gel-forming solution. Keratocytes align by contact guidance along the direction of collagen fibrils and respect the orthogonal design of the collagen template as they penetrate into the bulk of the 3D matrix. The scaffold is a significant step towards the creation of a corneal substitute with properties resembling those of native corneal stroma.
Collapse
Affiliation(s)
- Jim Torbet
- Institut de Biologie et Chimie des Protéines, CNRS UMR 5086, IFR 128 Biosciences Lyon-Gerland, 69367 Lyon, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
67
|
Gobeaux F, Belamie E, Mosser G, Davidson P, Panine P, Giraud-Guille MM. Cooperative ordering of collagen triple helices in the dense state. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:6411-7. [PMID: 17441743 DOI: 10.1021/la070093z] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Extracellular matrixes such as bone, skin, cornea, and tendon have ordered structures comprised for the most part of collagen, an elongated protein of well-defined dimensions and composition. Here we show how the cooperative ordering of collagen triple helices in the dense fluid state is exploited to produce dense ordered collagen matrixes. The spontaneous formation of a birefringent phase occurs at critical concentrations that increase from 50-60 to 80-85 mg/mL as the acetic acid concentration of the solvent increases from 5 to 500 mM. We studied by small-angle X-ray scattering (SAXS) the local liquidlike positional order across the isotropic/anisotropic phase transition by unwinding the cholesteric phase with moderate shearing stress. Interparticle scattering gives rise to a broad interference peak. The average distance between triple helices, dav, is thus estimated and decreases linearly as a function of phi-1/2 from 12.7 +/- 0.9 nm (22.5 mg/mL) to 5.0 +/- 0.6 nm (166.4 mg/mL). Equilibrium concentrations and the order parameter of the nematic phase agree reasonably well with theoretical predictions for semiflexible macromolecules. Striated fibrils with a high degree of alignment were obtained by fine-tuning the delicately balanced electrostatic interactions, which yielded strong elastic gels with a hierarchical organization very similar to that of major biological tissues. Typical Bragg reflections corresponding to the 67 nm period characteristic of collagen fibrils in biological tissues were recorded by SAXS with ordered collagen matrixes reconstituted in vitro.
Collapse
Affiliation(s)
- F Gobeaux
- Chimie de la Matière Condensée, UMR 7574 CNRS-Université Pierre et Marie Curie, ENSCP-Ecole Pratique des Hautes Etudes, 12 rue Cuvier, 75005 Paris, France
| | | | | | | | | | | |
Collapse
|
68
|
Marotta R, Shain DH. Irregular helicoids in leech cocoon membranes. J Struct Biol 2007; 158:336-43. [PMID: 17336091 DOI: 10.1016/j.jsb.2006.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 12/08/2006] [Accepted: 12/09/2006] [Indexed: 10/23/2022]
Abstract
Helicoids in the cocoon membrane of leeches Theromyzon tessulatum and Erpobdella punctata comprise a twisted superposition of layers, each containing a variable number of planes formed by unidirectional fibrils. Straight fibrils intersecting at different angles were displayed in tangential sections through the cocoon wall of each species. When the sectioning angle was below a certain value (i.e., the critical angle), bow-shaped lines apparent in oblique sections were replaced by a succession of layers containing straight fibrils, permitting a direct measurement of step-angle change between successive layers in a helicoid. By this methodology, we determined that no regularities exist in the succession of step-angles or in layer thicknesses within the cocoon membranes, but that the distribution of step-angles between layers was unique for each cocoon type.
Collapse
Affiliation(s)
- Roberto Marotta
- Department of Biology, 315 Penn Street, Science Buliding, Rutgers The State University of New Jersey, Camden, NJ 08102, USA
| | | |
Collapse
|
69
|
Bitar M, Salih V, Brown RA, Nazhat SN. Effect of multiple unconfined compression on cellular dense collagen scaffolds for bone tissue engineering. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2007; 18:237-44. [PMID: 17323154 DOI: 10.1007/s10856-006-0685-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 09/19/2006] [Indexed: 05/14/2023]
Abstract
Plastic compression of hydrated collagen gels rapidly produces biomimetic scaffolds of improved mechanical properties. These scaffolds can potentially be utilised as cell seeded systems for bone tissue engineering. This work investigated the influence of multiple unconfined compression on the biocompatibility and mechanical properties of such systems. Single and double compressed dense collagen matrices were produced and characterised for protein dry weight, morphology and mechanical strength. Compression related maintenance of the seeded HOS TE85 cell line viability in relation to the extent of compression was evaluated up to 10 days in culture using the TUNEL assay. Fluorescence Live/Dead assay was conducted to examine overall cell survival and morphology. Cell induced structural changes in the dense collagenous scaffolds were assessed by routine histology. The mechanical properties of the cellular scaffolds were also evaluated as a function of time in culture. It is clear that a single plastic compression step produced dense collagenous scaffolds capable of maintaining considerable cell viability and function as signs of matrix remodeling, and maintenance of mechanical properties were evident. Such scaffolds should therefore be further developed as systems for bone tissue regeneration.
Collapse
Affiliation(s)
- Malak Bitar
- Divsion of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London, WC1X 8LD, UK.
| | | | | | | |
Collapse
|
70
|
Guo C, Kaufman LJ. Flow and magnetic field induced collagen alignment. Biomaterials 2006; 28:1105-14. [PMID: 17112582 DOI: 10.1016/j.biomaterials.2006.10.010] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Accepted: 10/09/2006] [Indexed: 10/23/2022]
Abstract
A straightforward technique to align thin collagen gels is presented. This technique requires only collagen solution, surface-modified magnetic beads, a small magnet, and an incubator. As such, this is the only collagen alignment technique that requires no specialized equipment. The collagen gels are imaged with confocal reflectance microscopy, and degree of alignment is quantitatively assessed using image analysis techniques that allow for identification of fiber position and angular distribution. A series of experiments shows that magnetic beads coated with streptavidin lead to the most highly aligned gels. Rheology and microscopy experiments suggest that alignment results from bead coupling to, and entrainment and entrapment in, collagen fibrils during their assembly into fibers that form a sample-spanning gel. The timescales of gelation and bead motion to the poles of the external magnet must be similar to effect good alignment over large areas with this technique. It is also demonstrated that alignment can be attained in both plain and cell-bearing gels that are several millimeters thick.
Collapse
Affiliation(s)
- Cheng Guo
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | | |
Collapse
|
71
|
Giraud Guille MM, Mosser G, Helary C, Eglin D. Bone matrix like assemblies of collagen: from liquid crystals to gels and biomimetic materials. Micron 2005; 36:602-8. [PMID: 16169238 DOI: 10.1016/j.micron.2005.07.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Revised: 06/22/2005] [Accepted: 07/04/2005] [Indexed: 11/24/2022]
Abstract
Skeletal tissues associate in close interaction, a dense organic matrix and a mineral network. In bone, the major structural protein is type I collagen, associated with inorganic crystals of hydroxyapatite. The three-dimensional arrangement of collagen fibrils in compact bone forms regularly ordered networks and a parallel was evidenced between these structures and molecular assemblies described in liquid crystals. Similar structures are now obtained in vitro. Indeed, when purified type I collagen is highly concentrated in an acid soluble state, the protein spontaneously assembles into ordered liquid crystalline phases. After a sol/gel transition triggered by pH increase, biomimetic materials are formed which resemble the exact compact bone matrix architecture over distances reaching centimetres and more. The properties of these highly ordered materials will be reviewed recalling their supramolecular arrangement and the corresponding patterns when visualised in polarised light microscopy (birefringence) and transmission electron microscopy (TEM). The association of inorganic phases (amorphous silica) to form chiral hybrid materials will also be described so as the behaviour of cells (fibroblast adhesion and migration) when seeded on these dense biomimetic matrices.
Collapse
Affiliation(s)
- Marie M Giraud Guille
- Laboratoire Chimie de la Matière Condensée, Ecole Pratique des Hautes Etudes, Matériaux du Vivant, Université P & Marie Curie, CNRS-UMR 7574, 12 rue Cuvier, 75005 Paris, France.
| | | | | | | |
Collapse
|