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Yu Z, Baptist AV, Reinhardt SCM, Bertosin E, Dekker C, Jungmann R, Heuer-Jungemann A, Caneva S. Compliant DNA Origami Nanoactuators as Size-Selective Nanopores. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2405104. [PMID: 39014922 DOI: 10.1002/adma.202405104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/20/2024] [Indexed: 07/18/2024]
Abstract
Biological nanopores crucially control the import and export of biomolecules across lipid membranes in cells. They have found widespread use in biophysics and biotechnology, where their typically narrow, fixed diameters enable selective transport of ions and small molecules, as well as DNA and peptides for sequencing applications. Yet, due to their small channel sizes, they preclude the passage of large macromolecules, e.g., therapeutics. Here, the unique combined properties of DNA origami nanotechnology, machine-inspired design, and synthetic biology are harnessed, to present a structurally reconfigurable DNA origami MechanoPore (MP) that features a lumen that is tuneable in size through molecular triggers. Controllable switching of MPs between 3 stable states is confirmed by 3D-DNA-PAINT super-resolution imaging and through dye-influx assays, after reconstitution of the large MPs in the membrane of liposomes via an inverted-emulsion cDICE technique. Confocal imaging of transmembrane transport shows size-selective behavior with adjustable thresholds. Importantly, the conformational changes are fully reversible, attesting to the robust mechanical switching that overcomes pressure from the surrounding lipid molecules. These MPs advance nanopore technology, offering functional nanostructures that can be tuned on-demand - thereby impacting fields as diverse as drug delivery, biomolecule sorting, and sensing, as well as bottom-up synthetic biology.
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Affiliation(s)
- Ze Yu
- Department of Precision and Microsystems Engineering, Delft University of Technology, Mekelweg 2, Delft, 2628 CD, The Netherlands
| | - Anna V Baptist
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Bavaria, Germany
- Germany and Center for NanoScience, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539, Munich, Bavaria, Germany
| | - Susanne C M Reinhardt
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Bavaria, Germany
- Germany and Center for NanoScience, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539, Munich, Bavaria, Germany
- Faculty of Physics, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539, Munich, Bavaria, Germany
| | - Eva Bertosin
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2629 HZ, The Netherlands
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2629 HZ, The Netherlands
| | - Ralf Jungmann
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Bavaria, Germany
- Germany and Center for NanoScience, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539, Munich, Bavaria, Germany
- Faculty of Physics, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539, Munich, Bavaria, Germany
| | - Amelie Heuer-Jungemann
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Bavaria, Germany
- Germany and Center for NanoScience, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539, Munich, Bavaria, Germany
| | - Sabina Caneva
- Department of Precision and Microsystems Engineering, Delft University of Technology, Mekelweg 2, Delft, 2628 CD, The Netherlands
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Sise CV, Petersen CA, Ashford AK, Yun J, Zimmerman BK, Vukelic S, Hung CT, Ateshian GA. A major functional role of synovial fluid is to reduce the rate of cartilage fatigue failure under cyclical compressive loading. Osteoarthritis Cartilage 2024:S1063-4584(24)01362-1. [PMID: 39209247 DOI: 10.1016/j.joca.2024.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 07/05/2024] [Accepted: 08/03/2024] [Indexed: 09/04/2024]
Abstract
OBJECTIVE Based on our recent study, which showed that cartilage fatigue failure in reciprocating sliding contact results from cyclical compressive forces, not from cyclical frictional forces, we hypothesize that a major functional role for synovial fluid (SF) is to reduce the rate of articular cartilage fatigue failure from cyclical compressive loading. DESIGN The rate of cartilage fatigue failure due to repetitive compressive loading was measured by sliding a glass lens against an immature bovine cartilage tibial plateau strip immersed in mature bovine SF, phosphate-buffered saline (PBS), or SF/PBS dilutions (50% SF and 25% SF; n = 8 for all four bath conditions). After 24 h of reciprocating sliding (5400 cycles), samples were visually assessed, and if damage was observed, the test was terminated; otherwise, testing was continued for 72 h (16,200 cycles), with solution refreshed daily. RESULTS All eight samples in the PBS group exhibited physical damage after 24 h, with an average final surface roughness of Rq= 0.210 ± 0.067 mm. The SF group showed no damage after 24 h; however, two of eight samples became damaged after 72 h, producing a significantly lower average surface roughness than the PBS group (Rq=0.059 ± 0.030 mm; p < 10-4). For the remaining groups, at 72 h, one of eight samples was damaged in the 50% SF group, and five of eight samples were damaged in the 25% SF group. CONCLUSIONS The results strongly support our hypothesis, showing that decreased amounts of SF in the testing bath produce increased rates of fatigue failure in cartilage that was subjected to reciprocating sliding contact.
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Affiliation(s)
- C V Sise
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - C A Petersen
- Department of Mechanical Engineering, Columbia University, New York, NY, United States
| | - A K Ashford
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - J Yun
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - B K Zimmerman
- Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - S Vukelic
- Department of Mechanical Engineering, Columbia University, New York, NY, United States
| | - C T Hung
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - G A Ateshian
- Department of Biomedical Engineering, Columbia University, New York, NY, United States; Department of Mechanical Engineering, Columbia University, New York, NY, United States.
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Single Hydrogel Particle Mechanics and Dynamics Studied by Combining Capillary Micromechanics with Osmotic Compression. Gels 2023; 9:gels9030194. [PMID: 36975643 PMCID: PMC10048562 DOI: 10.3390/gels9030194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 03/08/2023] Open
Abstract
Hydrogels can exhibit a remarkably complex response to external stimuli and show rich mechanical behavior. Previous studies of the mechanics of hydrogel particles have generally focused on their static, rather than dynamic, response, as traditional methods for measuring single particle response at the microscopic scale cannot readily measure time-dependent mechanics. Here, we study both the static and the time-dependent response of a single batch of polyacrylamide (PAAm) particles by combining direct contact forces, applied by using Capillary Micromechanics, a method where particles are deformed in a tapered capillary, and osmotic forces are applied by a high molecular weight dextran solution. We found higher values of the static compressive and shear elastic moduli for particles exposed to dextran, as compared to water (KDex≈63 kPa vs. Kwater≈36 kPa, and GDex≈16 kPa vs. Gwater≈7 kPa), which we accounted for, theoretically, as being the result of the increased internal polymer concentration. For the dynamic response, we observed surprising behavior, not readily explained by poroelastic theories. The particles exposed to dextran solutions deformed more slowly under applied external forces than did those suspended in water (τDex≈90 s vs. τwater≈15 s). The theoretical expectation was the opposite. However, we could account for this behaviour by considering the diffusion of dextran molecules in the surrounding solution, which we found to dominate the compression dynamics of our hydrogel particles suspended in dextran solutions.
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Sebastia-Saez D, Benaouda F, Lim CH, Lian G, Jones SA, Cui L, Chen T. In-Silico Modelling of Transdermal Delivery of Macromolecule Drugs Assisted by a Skin Stretching Hypobaric Device. Pharm Res 2023; 40:295-305. [PMID: 36348132 PMCID: PMC9911480 DOI: 10.1007/s11095-022-03423-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/21/2022] [Indexed: 11/09/2022]
Abstract
OBJECTIVES To develop a simulation model to explore the interplay between mechanical stretch and diffusion of large molecules into the skin under locally applied hypobaric pressure, a novel penetration enhancement method. METHODS Finite element method was used to model the skin mechanical deformation and molecular diffusion processes, with validation against in-vitro transdermal permeation experiments. Simulations and experimental data were used together to investigate the transdermal permeation of large molecules under local hypobaric pressure. RESULTS Mechanical simulations resulted in skin stretching and thinning (20%-26% hair follicle diameter increase, and 21%-27% skin thickness reduction). Concentration of dextrans in the stratum corneum was below detection limit with and without hypobaric pressure. Concentrations in viable epidermis and dermis were not affected by hypobaric pressure (approximately 2 μg [Formula: see text] cm-2). Permeation into the receptor fluid was substantially enhanced from below the detection limit at atmospheric pressure to up to 6 μg [Formula: see text] cm-2 under hypobaric pressure. The in-silico simulations compared satisfactorily with the experimental results at atmospheric conditions. Under hypobaric pressure, satisfactory comparison was attained when the diffusion coefficients of dextrans in the skin layers were increased from [Formula: see text] 10 μm2 [Formula: see text] s-1 to between 200-500 μm2 [Formula: see text] s-1. CONCLUSIONS Application of hypobaric pressure induces skin mechanical stretching and enlarges the hair follicle. This enlargement alone cannot satisfactorily explain the increased transdermal permeation into the receptor fluid under hypobaric pressure. The results from the in-silico simulations suggest that the application of hypobaric pressure increases diffusion in the skin, which leads to improved overall transdermal permeation.
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Affiliation(s)
- Daniel Sebastia-Saez
- Department of Chemical and Process Engineering, University of Surrey, Guildford, UK
| | - Faiza Benaouda
- Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Chui Hua Lim
- Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Guoping Lian
- Department of Chemical and Process Engineering, University of Surrey, Guildford, UK
- Unilever R&D Colworth, Bedford, UK
| | - Stuart A Jones
- Institute of Pharmaceutical Science, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Liang Cui
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, UK
| | - Tao Chen
- Department of Chemical and Process Engineering, University of Surrey, Guildford, UK.
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5
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Tian D, Qu Z, Lai T, Zhu G. A prediction model for nanoparticle diffusion behavior in fibrous materials considering steric and hydrodynamic resistances. Phys Chem Chem Phys 2022; 24:24394-24403. [PMID: 36189674 DOI: 10.1039/d2cp03397f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Precise prediction of the hindered diffusion behavior of electroneutral particles in fibrous media plays a critical role in the development of drugs, polymer membranes, and porous electrodes. However, the random microstructure and unknown coupling relationship of multiple resistance mechanisms lead to the lack of a universal prediction model. In this work, a dual-resistance model is proposed by reconstructed pore-scale simulations, which presents the coexistence of steric and hydrodynamic resistances in the multiplication form. The simulation results show that the relationship between steric resistance and structural parameters (porosity, fiber radius, and particle radius) is exponential, while that for hydrodynamic resistance is polynomial. The dominant diffusion resistance is found to change from hydrodynamic to steric resistance with a decrease in porosity. The fluorescent polystyrene microsphere diffusivity in a series of SiO2 fibrous media is determined by single-particle tracking experiments, quantitatively confirming the dual-resistance model. The present model can be used for rapid diffusivity prediction and fibrous membrane and drug design.
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Affiliation(s)
- Di Tian
- MOE Key Laboratory of Thermal-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Zhiguo Qu
- MOE Key Laboratory of Thermal-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Tao Lai
- MOE Key Laboratory of Thermal-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Guodong Zhu
- Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, P. R. China
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Anderson AR, Nicklow E, Segura T. Particle fraction is a bioactive cue in granular scaffolds. Acta Biomater 2022; 150:111-127. [PMID: 35917913 PMCID: PMC10329855 DOI: 10.1016/j.actbio.2022.07.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/15/2022] [Accepted: 07/26/2022] [Indexed: 11/27/2022]
Abstract
Microporous annealed particle (MAP) hydrogels are porous 3D scaffolds generated by interlinking randomly packed microgels (µgels). Particle fraction, hydrogel stiffness, microparticle shape, and crosslinking chemistry are paramount to the microstructure that microgels make within MAP scaffolds. Of these parameters, control over the particle fraction in MAP scaffolds varies greatly by user and drying technique, leading to inconsistent microarchitectures. These inconsistencies have biological ramifications, as the particle fraction of MAP scaffolds determines the void space within the material which strongly impacts cell growth. Here, we describe a method of freeze-drying microgels that leads to consistent and user-defined particle fractions by weighing the dried microgel powder and reconstituting at known volumes. Though freeze-drying hydrogels typically leads to ice crystal and cryogel formation, we report on mediums that result in freeze-dried microgels that retain their original properties when rehydrated. By rehydrating lyophilized microgels to form MAP scaffolds, we demonstrate that particle fraction controls the bulk scaffold stiffness, but not local microgel stiffness. Further, the particle fraction in MAP scaffolds directly affects cell growth and macromolecular diffusion. Using controlled particle fractions in MAP scaffolds, we can now reproducibly assess mechanical properties, diffusion of macromolecules, and cell responses within user-defined microarchitectures. STATEMENT OF SIGNIFICANCE: The porosity of biomaterials is one key characteristic that influences cell infiltration and growth. Granular hydrogels are a class of biomaterials that are comprised of small, building block components that boast a porous architecture in the void space between the particles. Controlling the composition of these granular materials is key to guiding cell responses. In this work, we demonstrate methods for controlling the fraction of the material containing hydrogel versus void space. As a result, we can now reproducibly study the effect of particle fraction on cell responses, mechanical properties, and mass transport in granular hydrogels.
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Affiliation(s)
- Alexa R Anderson
- Department of Biomedical Engineering, Duke University, 534 Research Drive, Durham NC 27708-0281, United States
| | - Ethan Nicklow
- Department of Biomedical Engineering, Duke University, 534 Research Drive, Durham NC 27708-0281, United States
| | - Tatiana Segura
- Department of Biomedical Engineering, Duke University, 534 Research Drive, Durham NC 27708-0281, United States; Clinical Science Departments of Neurology and Dermatology, Duke University, 534 Research Drive, Durham NC 27708-0281, United States.
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7
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Mut SR, Mishra S, Vazquez M. A Microfluidic Eye Facsimile System to Examine the Migration of Stem-like Cells. MICROMACHINES 2022; 13:mi13030406. [PMID: 35334698 PMCID: PMC8954941 DOI: 10.3390/mi13030406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 02/24/2022] [Accepted: 02/24/2022] [Indexed: 02/05/2023]
Abstract
Millions of adults are affected by progressive vision loss worldwide. The rising incidence of retinal diseases can be attributed to damage or degeneration of neurons that convert light into electrical signals for vision. Contemporary cell replacement therapies have transplanted stem and progenitor-like cells (SCs) into adult retinal tissue to replace damaged neurons and restore the visual neural network. However, the inability of SCs to migrate to targeted areas remains a fundamental challenge. Current bioengineering projects aim to integrate microfluidic technologies with organotypic cultures to examine SC behaviors within biomimetic environments. The application of neural phantoms, or eye facsimiles, in such systems will greatly aid the study of SC migratory behaviors in 3D. This project developed a bioengineering system, called the μ-Eye, to stimulate and examine the migration of retinal SCs within eye facsimiles using external chemical and electrical stimuli. Results illustrate that the imposed fields stimulated large, directional SC migration into eye facsimiles, and that electro-chemotactic stimuli produced significantly larger increases in cell migration than the individual stimuli combined. These findings highlight the significance of microfluidic systems in the development of approaches that apply external fields for neural repair and promote migration-targeted strategies for retinal cell replacement therapy.
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Affiliation(s)
- Stephen Ryan Mut
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, 599 Taylor Rd, Piscataway, NJ 08854, USA;
| | - Shawn Mishra
- Regeneron, 777 Old Saw Mill River Rd, Tarrytown, NY 10591, USA;
| | - Maribel Vazquez
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, 599 Taylor Rd, Piscataway, NJ 08854, USA;
- Correspondence:
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Salipante PF, Hudson SD, Alimperti S. Blood vessel-on-a-chip examines the biomechanics of microvasculature. SOFT MATTER 2021; 18:117-125. [PMID: 34816867 PMCID: PMC9001019 DOI: 10.1039/d1sm01312b] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We use a three-dimensional (3D) microvascular platform to measure the elasticity and membrane permeability of the endothelial cell layer. The microfluidic platform is connected with a pneumatic pressure controller to apply hydrostatic pressure. The deformation is measured by tracking the mean vessel diameter under varying pressures up to 300 Pa. We obtain a value for the Young's modulus of the cell layer in low strain where a linear elastic response is observed and use a hyperelastic model that describes the strain hardening observed at larger strains (pressure). A fluorescent dye is used to track the flow through the cell layer to determine the membrane flow resistance as a function of applied pressure. Finally, we track the 3D positions of cell nuclei while the vessel is pressurized to observe local deformation and correlate inter-cell deformation with the local structure of the cell layer. This approach is able to probe the mechanical properties of blood vessels in vitro and provides a methodology for investigating microvascular related diseases.
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Affiliation(s)
- Paul F Salipante
- Polymers and Complex Fluids Group, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, USA.
| | - Steven D Hudson
- Polymers and Complex Fluids Group, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, USA.
| | - Stella Alimperti
- ADA Science and Research Institute, 100 Bureau Dr, Gaithersburg, MD, 20899, USA
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9
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Liao Y, Mechulam Y, Lassalle-Kaiser B. A millisecond passive micromixer with low flow rate, low sample consumption and easy fabrication. Sci Rep 2021; 11:20119. [PMID: 34635693 PMCID: PMC8505571 DOI: 10.1038/s41598-021-99471-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/17/2021] [Indexed: 11/30/2022] Open
Abstract
Fast mixing of small volumes of solutions in microfluidic devices is essential for an accurate control and observation of the dynamics of a reaction in biological or chemical studies. It is often, however, a challenging task, as the Reynolds number (Re) in microscopic devices is typically < 100. In this report, we detail a novel mixer based on the “staggered herring bone” (SHB) pattern and “split-recombination” strategies with an optimized geometry, the periodic rotation of the flow structure can be controlled and recombined in a way that the vortices and phase shifts of the flow induce intertwined lamellar structures, thus increasing the contact surface and enhancing mixing. The optimization improves the mixing while using a low flow rate, hence a small volume for mixing and moderate pressure drops. The performances of the patterns were first simulated using COMSOL Multiphysics under different operating conditions. The simulation indicates that at very low flow rate (1–12 µL·min−1) and Re (3.3–40), as well as a very small working volume (~ 3 nL), a very good mixing (~ 98%) can be achieved in the ms time range (4.5–78 ms). The most promising design was then visualized experimentally, showing results that are consistent with the outcomes of the simulations. Importantly, the devices were fabricated using a classical soft-lithography method, as opposed to additive manufacturing often used to generate complex mixing structures. This new device minimizes the sample consumption and could therefore be applied for studies using precious samples.
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Affiliation(s)
- Yuanyuan Liao
- Synchrotron SOLEIL, l'Orme des Merisiers, 91192, Gif-sur-Yvette, France. .,IamFluidics BV, High Tech Factory, De Veldmaat 17, 7522 NM, Enschede, The Netherlands.
| | - Yves Mechulam
- Laboratoire de Biologie Structurale de la Cellule, BIOC, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 91128, Palaiseau Cedex, France
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10
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Zimmerman BK, Nims RJ, Chen A, Hung CT, Ateshian GA. Direct Osmotic Pressure Measurements in Articular Cartilage Demonstrate Nonideal and Concentration-Dependent Phenomena. J Biomech Eng 2021; 143:041007. [PMID: 33210125 PMCID: PMC7872001 DOI: 10.1115/1.4049158] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/01/2020] [Indexed: 11/08/2022]
Abstract
The osmotic pressure in articular cartilage serves an important mechanical function in healthy tissue. Its magnitude is thought to play a role in advancing osteoarthritis. The aims of this study were to: (1) isolate and quantify the magnitude of cartilage swelling pressure in situ; and (2) identify the effect of salt concentration on material parameters. Confined compression stress-relaxation testing was performed on 18 immature bovine and six mature human cartilage samples in solutions of varying osmolarities. Direct measurements of osmotic pressure revealed nonideal and concentration-dependent osmotic behavior, with magnitudes approximately 1/3 those predicted by ideal Donnan law. A modified Donnan constitutive behavior was able to capture the aggregate behavior of all samples with a single adjustable parameter. Results of curve-fitting transient stress-relaxation data with triphasic theory in febio demonstrated concentration-dependent material properties. The aggregate modulus HA increased threefold as the external concentration decreased from hypertonic 2 M to hypotonic 0.001 M NaCl (bovine: HA=0.420±0.109 MPa to 1.266±0.438 MPa; human: HA=0.499±0.208 MPa to 1.597±0.455 MPa), within a triphasic theory inclusive of osmotic effects. This study provides a novel and simple analytical model for cartilage osmotic pressure which may be used in computational simulations, validated with direct in situ measurements. A key finding is the simultaneous existence of Donnan osmotic and Poisson-Boltzmann electrostatic interactions within cartilage.
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Affiliation(s)
- Brandon K Zimmerman
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Robert J Nims
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Alex Chen
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Clark T Hung
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Gerard A Ateshian
- Department of Mechanical Engineering, Columbia University, New York, NY 10027; Department of Biomedical Engineering, Columbia University, New York, NY 10027
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11
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Wang X, June RK, Pierce DM. A 3-D constitutive model for finite element analyses of agarose with a range of gel concentrations. J Mech Behav Biomed Mater 2020; 114:104150. [PMID: 33214108 DOI: 10.1016/j.jmbbm.2020.104150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/02/2020] [Accepted: 10/17/2020] [Indexed: 11/25/2022]
Abstract
Hydrogels have seen widespread application across biomedical sciences and there is considerable interest in using hydrogels, including agarose, for creating in vitro three-dimensional environments to grow cells and study mechanobiology and mechanotransduction. Recent advances in the preparation of agarose gels enable successful encapsulation of viable cells at gel concentrations as high as 5%. Agarose with a range of gel concentrations can thus serve as an experimental model mimicking changes in the 3-D microenvironment of cells during disease progression and can facilitate experiments aimed at probing the corresponding mechanobiology, e.g. the evolving mechanobiology of chondrocytes during the progression of osteoarthritis. Importantly, whether stresses (forces) or strains (displacements) drive mechanobiology and mechanotransduction is currently unknown. We can use experiments to quantify mechanical properties of hydrogels, and imaging to estimate microstructure and even strains; however, only computational models can estimate intra-gel stresses in cell-seeded agarose constructs because the required in vitro experiments are currently impossible. Finite element modeling is well-established for (computational) mechanical analyses, but accurate constitutive models for modeling the 3-D mechanical environments of cells within high-stiffness agarose with varying gel concentrations are currently unavailable. In this study we aimed to establish a 3-D constitutive model of high-stiffness agarose with a range of gel concentrations. We applied a multi-step, physics-based optimization approach to separately fit subsets of model parameters and help achieve robust convergence. Our constitutive model, fitted to experimental data on progressive stress-relaxations, was able to predict reaction forces determined from independent experiments on cyclical loading. Our model has broad applications in finite element modeling aimed at interpreting mechanical experiments on agarose specimens seeded with cells, particularly in predicting distributions of intra-gel stresses. Our model and fitted parameters enable more accurate finite element simulations of high-stiffness agarose constructs, and thus better understanding of experiments aimed at mechanobiology, mechanotransduction, or other applications in tissue engineering.
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Affiliation(s)
- Xiaogang Wang
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT, USA
| | - Ronald K June
- Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, MT, USA
| | - David M Pierce
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT, USA; Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA.
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12
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Guang Y, McGrath TM, Klug NR, Nims RJ, Shih CC, Bayguinov PO, Guilak F, Pham CTN, Fitzpatrick JAJ, Setton LA. Combined Experimental Approach and Finite Element Modeling of Small Molecule Transport Through Joint Synovium to Measure Effective Diffusivity. J Biomech Eng 2020; 142:041010. [PMID: 31536113 PMCID: PMC7104772 DOI: 10.1115/1.4044892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/14/2019] [Indexed: 11/08/2022]
Abstract
Trans-synovial solute transport plays a critical role in the clearance of intra-articularly (IA) delivered drugs. In this study, we present a computational finite element model (FEM) of solute transport through the synovium validated by experiments on synovial explants. Unsteady diffusion of urea, a small uncharged molecule, was measured through devitalized porcine and human synovium using custom-built diffusion chambers. A multiphasic computational model was constructed and optimized with the experimental data to extract effective diffusivity for urea within the synovium. A monotonic decrease in urea concentration was observed in the donor bath over time, with an effective diffusivity found to be an order of magnitude lower in synovium versus that measured in free solution. Parametric studies incorporating an intimal cell layer with varying thickness and varying effective diffusivities were performed, revealing a dependence of drug clearance kinetics on both parameters. The findings of this study indicate that the synovial matrix impedes urea solute transport out of the joint with little retention of the solute in the matrix.
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Affiliation(s)
- Young Guang
- Department of Biomedical Engineering, Washington University in
St. Louis, Whitaker Hall, 1 Brookings Dr., St.
Louis, MO 63130
e-mail:
| | - Tom M. McGrath
- Department of Biomedical Engineering, Washington University in
St. Louis, Whitaker Hall, 1 Brookings Dr., St.
Louis, MO 63130
e-mail:
| | - Natalie R. Klug
- Department of Biomedical Engineering, Washington University in
St. Louis, Whitaker Hall, 1 Brookings Dr., St.
Louis, MO 63130
e-mail:
| | - Robert J. Nims
- Department of Orthopaedic Surgery, Washington University School
of Medicine, St. Louis, MO 63110
e-mail:
| | - Chien-Cheng Shih
- Center for Cellular Imaging, Department of Neuroscience,
Washington University School of Medicine, St.
Louis, MO 63110
e-mail:
| | - Peter O. Bayguinov
- Center for Cellular Imaging, Department of Neuroscience,
Washington University School of Medicine, St.
Louis, MO 63110
e-mail:
| | - Farshid Guilak
- Department of Orthopaedic Surgery, Washington University
School of Medicine, St. Louis, MO
63110 e-mail:
| | - Christine T. N. Pham
- Division of Rheumatology, Washington University School of
Medicine, St. Louis, MO 63110
e-mail:
| | - James A. J. Fitzpatrick
- Scientific Director Center for Cellular Imaging, Department of
Neuroscience, Department Cell Biology & Physiology and
Neuroscience, Washington University School of Medicine,
St. Louis, MO 63110;Department of Biomedical Engineering, Washington University in
St. Louis, Whitaker Hall, 1 Brookings Dr., St.
Louis, MO 63130
e-mail:
| | - Lori A. Setton
- Department of Biomedical Engineering, Washington University in
St. Louis, Whitaker Hall, 1 Brookings Dr., St.
Louis, MO 63130
e-mail:
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13
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Dravid A, Raos B, Aqrawe Z, Parittotokkaporn S, O'Carroll SJ, Svirskis D. A Macroscopic Diffusion-Based Gradient Generator to Establish Concentration Gradients of Soluble Molecules Within Hydrogel Scaffolds for Cell Culture. Front Chem 2019; 7:638. [PMID: 31620430 PMCID: PMC6759698 DOI: 10.3389/fchem.2019.00638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/04/2019] [Indexed: 01/28/2023] Open
Abstract
Concentration gradients of soluble molecules are ubiquitous within the living body and known to govern a number of key biological processes. This has motivated the development of numerous in vitro gradient-generators allowing researchers to study cellular response in a precise, controlled environment. Despite this, there remains a current paucity of simplistic, convenient devices capable of generating biologically relevant concentration gradients for cell culture assays. Here, we present the design and fabrication of a compartmentalized polydimethylsiloxane diffusion-based gradient generator capable of sustaining concentration gradients of soluble molecules within thick (5 mm) and thin (2 mm) agarose and agarose-collagen co-gel matrices. The presence of collagen within the agarose-collagen co-gel increased the mechanical properties of the gel. Our model molecules sodium fluorescein (376 Da) and FITC-Dextran (10 kDa) quickly established a concentration gradient that was maintained out to 96 h, with 24 hourly replenishment of the source and sink reservoirs. FITC-Dextran (40 kDa) took longer to establish in all hydrogel setups. The steepness of gradients generated are within appropriate range to elicit response in certain cell types. The compatibility of our platform with cell culture was demonstrated using a LIVE/DEAD® assay on terminally differentiated SH-SY5Y neurons. We believe this device presents as a convenient and useful tool that can be easily adopted for study of cellular response in gradient-based assays.
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Affiliation(s)
- Anusha Dravid
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
| | - Brad Raos
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
| | - Zaid Aqrawe
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Sam Parittotokkaporn
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Simon J. O'Carroll
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Darren Svirskis
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
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14
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López-Marcial GR, Zeng AY, Osuna C, Dennis J, García JM, O'Connell GD. Agarose-Based Hydrogels as Suitable Bioprinting Materials for Tissue Engineering. ACS Biomater Sci Eng 2018; 4:3610-3616. [PMID: 33450800 DOI: 10.1021/acsbiomaterials.8b00903] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hydrogels are useful materials as scaffolds for tissue engineering applications. Using hydrogels with additive manufacturing techniques has typically required the addition of techniques such as cross-linking or printing in sacrificial materials that negatively impact tissue growth to remedy inconsistencies in print fidelity. Thus, there is a need for bioinks that can directly print cell-laden constructs. In this study, agarose-based hydrogels commonly used for cartilage tissue engineering were compared to Pluronic, a hydrogel with established printing capabilities. Moreover, new material mixtures were developed for bioprinting by combining alginate and agarose. We compared mechanical and rheological properties, including yield stress, storage modulus, and shear thinning, as well as construct shape fidelity to assess their potential as a bioink for cell-based tissue engineering. The rheological properties and printability of agarose-alginate gels were statistically similar to those of Pluronic for all tests (p > 0.05). Alginate-agarose composites prepared with 5% w/v (3:2 agarose to alginate ratio) demonstrated excellent cell viability over a 28-day culture period (>∼70% cell survival at day 28) as well matrix production over the same period. Therefore, agarose-alginate mixtures showed the greatest potential as an effective bioink for additive manufacturing of biological materials for cartilage tissue engineering.
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Affiliation(s)
- Gabriel R López-Marcial
- Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States
| | - Anne Y Zeng
- Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States
| | - Carlos Osuna
- Department of Mechanical Engineering, University of California, San Diego, California 92093, United States
| | - Joseph Dennis
- Department of Chemistry and Materials, IBM Almaden Research Center, San Jose, California 95120, United States
| | - Jeannette M García
- Department of Chemistry and Materials, IBM Almaden Research Center, San Jose, California 95120, United States
| | - Grace D O'Connell
- Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States.,Department of Orthopaedic Surgery, University of California, San Francisco, California 94143, United States
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15
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Polo Fonseca L, Trinca RB, Felisberti MI. Amphiphilic polyurethane hydrogels as smart carriers for acidic hydrophobic drugs. Int J Pharm 2018; 546:106-114. [DOI: 10.1016/j.ijpharm.2018.05.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/25/2018] [Accepted: 05/13/2018] [Indexed: 12/12/2022]
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16
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Han G, Hong D, Lee BS, Ha E, Park JH, Choi IS, Kang SM, Lee JK. Systematic Study of Functionalizable, Non-Biofouling Agarose Films with Protein and Cellular Patterns on Glass Slides. Chem Asian J 2017; 12:846-852. [PMID: 28218479 DOI: 10.1002/asia.201700010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/19/2017] [Indexed: 01/28/2023]
Abstract
Herein we demonstrate a systematic investigation of chemically functionalizable, non-biofouling agarose films over large-area glass surfaces. Agarose films, prepared with various concentrations of aqueous agarose, were activated by using periodate oxidation to generate aldehyde groups at the termini of the agarose chains. The non-biofouling efficacy and binding capabilities of the activated films were evaluated by using protein and cellular patterning, performed by using a microarrayer, microcontact printing, and micromolding in capillaries. Characterization by using a fluorescence slide scanner and a scanning-probe microscope revealed that the pore sizes of the agarose films played an important role in achieving desirable film performance; the 0.2 wt % agarose film exhibited the optimum efficacy in this work.
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Affiliation(s)
- Gyeongyeop Han
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu, 41566, South Korea
| | - Daehwa Hong
- Department of Chemistry and Center for Cell-Encapsulation, KAIST, Daejeon, 34141, South Korea
| | - Bong Soo Lee
- Department of Chemistry and Center for Cell-Encapsulation, KAIST, Daejeon, 34141, South Korea
| | - EunRae Ha
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu, 41566, South Korea
| | - Ji Hun Park
- Department of Chemistry and Center for Cell-Encapsulation, KAIST, Daejeon, 34141, South Korea
| | - Insung S Choi
- Department of Chemistry and Center for Cell-Encapsulation, KAIST, Daejeon, 34141, South Korea
| | - Sung Min Kang
- Department of Chemistry, Chungbuk National University, Cheongju, 28644, South Korea
| | - Jungkyu K Lee
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu, 41566, South Korea
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17
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Manzano S, Doblaré M, Doweidar MH. Parameter-dependent behavior of articular cartilage: 3D mechano-electrochemical computational model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2015; 122:491-502. [PMID: 26506530 DOI: 10.1016/j.cmpb.2015.09.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/02/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND AND OBJECTIVE Changes in mechano-electrochemical properties of articular cartilage play an essential role in the majority of cartilage diseases. Despite of this importance, the specific effect of each parameter into tissue behavior remains still obscure. Parametric computational modeling of cartilage can provide some insights into this matter, specifically the study of mechano-electrochemical properties variation and their correlation with tissue swelling, water and ion fluxes. Thus, the aim of this study is to evaluate the influence of the main mechanical and electrochemical parameters on the determination of articular cartilage behavior by a parametric analysis through a 3D finite element model. METHODS For this purpose, a previous 3D mechano-electrochemical model, developed by the same authors, of articular cartilage behavior has been used. Young's modulus, Poisson coefficient, ion diffusivities and ion activity coefficients variations have been analyzed and quantified through monitoring tissue simulated response. RESULTS Simulation results show how Young's modulus and Poisson coefficient control tissue behavior rather than electrochemical properties. Meanwhile, ion diffusivity and ion activity coefficients appear to be vital in controlling velocity of incoming and outgoing fluxes. CONCLUSIONS This parametric study establishes a basic guide when defining the main properties that are essential to be included into computational modeling of articular cartilage providing a helpful tool in tissue simulations.
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Affiliation(s)
- Sara Manzano
- Group of Structural Mechanics and Materials Modelling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain; Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain
| | - Manuel Doblaré
- Group of Structural Mechanics and Materials Modelling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain; Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain
| | - Mohamed Hamdy Doweidar
- Group of Structural Mechanics and Materials Modelling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain; Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
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18
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Albro MB, Nims RJ, Durney KM, Cigan AD, Shim JJ, Vunjak-Novakovic G, Hung CT, Ateshian GA. Heterogeneous engineered cartilage growth results from gradients of media-supplemented active TGF-β and is ameliorated by the alternative supplementation of latent TGF-β. Biomaterials 2015; 77:173-185. [PMID: 26599624 DOI: 10.1016/j.biomaterials.2015.10.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/05/2015] [Accepted: 10/06/2015] [Indexed: 02/07/2023]
Abstract
Transforming growth factor beta (TGF-β) has become one of the most widely utilized mediators of engineered cartilage growth. It is typically exogenously supplemented in the culture medium in its active form, with the expectation that it will readily transport into tissue constructs through passive diffusion and influence cellular biosynthesis uniformly. The results of this investigation advance three novel concepts regarding the role of TGF-β in cartilage tissue engineering that have important implications for tissue development. First, through the experimental and computational analysis of TGF-β concentration distributions, we demonstrate that, contrary to conventional expectations, media-supplemented exogenous active TGF-β exhibits a pronounced concentration gradient in tissue constructs, resulting from a combination of high-affinity binding interactions and a high cellular internalization rate. These gradients are sustained throughout the entire culture duration, leading to highly heterogeneous tissue growth; biochemical and histological measurements support that while biochemical content is enhanced up to 4-fold at the construct periphery, enhancements are entirely absent beyond 1 mm from the construct surface. Second, construct-encapsulated chondrocytes continuously secrete large amounts of endogenous TGF-β in its latent form, a portion of which undergoes cell-mediated activation and enhances biosynthesis uniformly throughout the tissue. Finally, motivated by these prior insights, we demonstrate that the alternative supplementation of additional exogenous latent TGF-β enhances biosynthesis uniformly throughout tissue constructs, leading to enhanced but homogeneous tissue growth. This novel demonstration suggests that latent TGF-β supplementation may be utilized as an important tool for the translational engineering of large cartilage constructs that will be required to repair the large osteoarthritic defects observed clinically.
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Affiliation(s)
- Michael B Albro
- Department of Materials, Imperial College London, London, UK
| | - Robert J Nims
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Krista M Durney
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Alexander D Cigan
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Jay J Shim
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | | | - Clark T Hung
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - Gerard A Ateshian
- Department of Biomedical Engineering, Columbia University, New York, NY 10027.,Department of Mechanical Engineering, Columbia University, New York, NY 10027
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19
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O'Connell GD, Tan AR, Cui V, Bulinski JC, Cook JL, Attur M, Abramson SB, Ateshian GA, Hung CT. Human chondrocyte migration behaviour to guide the development of engineered cartilage. J Tissue Eng Regen Med 2015; 11:877-886. [PMID: 25627968 DOI: 10.1002/term.1988] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 10/24/2014] [Accepted: 12/09/2014] [Indexed: 01/01/2023]
Abstract
Tissue-engineering techniques have been successful in developing cartilage-like tissues in vitro using cells from animal sources. The successful translation of these strategies to the clinic will likely require cell expansion to achieve sufficient cell numbers. Using a two-dimensional (2D) cell migration assay to first identify the passage at which chondrocytes exhibited their greatest chondrogenic potential, the objective of this study was to determine a more optimal culture medium for developing three-dimensional (3D) cartilage-like tissues using human cells. We evaluated combinations of commonly used growth factors that have been shown to promote chondrogenic growth and development. Human articular chondrocytes (AC) from osteoarthritic (OA) joints were cultured in 3D environments, either in pellets or encapsulated in agarose. The effect of growth factor supplementation was dependent on the environment, such that matrix deposition differed between the two culture systems. ACs in pellet culture were more responsive to bone morphogenetic protein (BMP2) alone or combinations containing BMP2 (i.e. BMP2 with PDGF or FGF). However, engineered cartilage development within agarose was better for constructs cultured with TGFβ3. These results with agarose and pellet culture studies set the stage for the development of conditions appropriate for culturing 3D functional engineered cartilage for eventual use in human therapies. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Grace D O'Connell
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Andrea R Tan
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Victoria Cui
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - J Chloe Bulinski
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - James L Cook
- Missouri Orthopedic Institute, University of Missouri, Columbia, MO, USA
| | - Mukundan Attur
- Department of Medicine, New York University School of Medicine, and NYU Langone Medical Center, New York, NY, USA
| | - Steven B Abramson
- Department of Medicine, New York University School of Medicine, and NYU Langone Medical Center, New York, NY, USA
| | - Gerard A Ateshian
- Department of Biomedical Engineering, Columbia University, New York, NY, USA.,Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Clark T Hung
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
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20
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Yodmuang S, McNamara SL, Nover AB, Mandal BB, Agarwal M, Kelly TAN, Chao PHG, Hung C, Kaplan DL, Vunjak-Novakovic G. Silk microfiber-reinforced silk hydrogel composites for functional cartilage tissue repair. Acta Biomater 2015; 11:27-36. [PMID: 25281788 DOI: 10.1016/j.actbio.2014.09.032] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 08/21/2014] [Accepted: 09/18/2014] [Indexed: 01/20/2023]
Abstract
Cartilage tissue lacks an intrinsic capacity for self-regeneration due to slow matrix turnover, a limited supply of mature chondrocytes and insufficient vasculature. Although cartilage tissue engineering has achieved some success using agarose as a scaffolding material, major challenges of agarose-based cartilage repair, including non-degradability, poor tissue-scaffold integration and limited processing capability, have prompted the search for an alternative biomaterial. In this study, silk fiber-hydrogel composites (SF-silk hydrogels) made from silk microfibers and silk hydrogels were investigated for their potential use as a support material for engineered cartilage. We demonstrated the use of 100% silk-based fiber-hydrogel composite scaffolds for the development of cartilage constructs with properties comparable to those made with agarose. Cartilage constructs with an equilibrium modulus in the native tissue range were fabricated by mimicking the collagen fiber and proteoglycan composite architecture of native cartilage using biocompatible, biodegradable silk fibroin from Bombyx mori. Excellent chondrocyte response was observed on SF-silk hydrogels, and fiber reinforcement resulted in the development of more mechanically robust constructs after 42 days in culture compared to silk hydrogels alone. Thus, we demonstrate the versatility of silk fibroin as a composite scaffolding material for use in cartilage tissue repair to create functional cartilage constructs that overcome the limitations of agarose biomaterials, and provide a much-needed alternative to the agarose standard.
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Affiliation(s)
- Supansa Yodmuang
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | | | - Adam B Nover
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Biman B Mandal
- Department of Biotechnology, Indian Institute of Technology, Guwahati 781039, India
| | - Monica Agarwal
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Terri-Ann N Kelly
- Department of Biomedical Engineering, Tufts University, Medford, MA, USA
| | - Pen-hsiu Grace Chao
- Institute of Biomedical Engineering, School of Engineering and School of Medicine, National Taiwan University, Taipei, Taiwan
| | - Clark Hung
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, MA, USA
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21
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Farrell K, O'Conor D, Gonzalez M, Androjna C, Midura RJ, Tewari SN, Belovich J. Substrate concentration influences effective radial diffusion coefficient in canine cortical bone. Ann Biomed Eng 2014; 42:2577-88. [PMID: 25234132 DOI: 10.1007/s10439-014-1123-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 09/11/2014] [Indexed: 11/29/2022]
Abstract
Transport of nutrients and waste across osseous tissue is dependent on the dynamic micro and macrostructure of the tissue; however little quantitative data exists examining how this transport occurs across the entire tissue. Here we investigate in vitro radial diffusion across a section of canine tissue, at dimensions of several hundred microns to millimeters, specifically between several osteons connected through a porous microstructure of Volkmann's canals and canaliculi. The effective diffusion coefficient is measured by a "sample immersion" technique presented here, in which the tissue sample was immersed in solution for 18-30 h, image analysis software was used to quantify the solute concentration profile in the tissue, and the data were fit to a mathematical model of diffusion in the tissue. Measurements of the effective diffusivity of sodium fluorescein using this technique were confirmed using a standard two-chamber diffusion system. As the solute concentration increased, the effective diffusivity decreased, ranging from 1.6 × 10(-7) ± 3.2 × 10(-8) cm(2)/s at 0.3 μM to 1.4 × 10(-8) ± 1.9 × 10(-9) cm(2)/s at 300 μM. The results show that there is no significant difference in mean diffusivity obtained using the two measurement techniques on the same sample, 3.3 × 10(-8) ± 3.3 × 10(-9) cm(2)/s (sample immersion), compared to 4.4 × 10(-8) ± 1.1 × 10(-8) cm(2)/s (diffusion chamber).
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Affiliation(s)
- Kurt Farrell
- Department of Chemical and Biomedical Engineering, Cleveland State University, 2121 Euclid Ave, Cleveland, OH, 44141, USA,
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22
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Silvast TS, Jurvelin JS, Tiitu V, Quinn TM, Töyräs J. Bath Concentration of Anionic Contrast Agents Does Not Affect Their Diffusion and Distribution in Articular Cartilage In Vitro. Cartilage 2013; 4:42-51. [PMID: 26069649 PMCID: PMC4297109 DOI: 10.1177/1947603512451023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Differences in contrast agent diffusion reflect changes in composition and structure of articular cartilage. However, in clinical application the contrast agent concentration in the joint capsule varies, which may affect the reliability of contrast enhanced cartilage tomography (CECT). In the present study, effects of concentration of x-ray contrast agents on their diffusion and equilibrium distribution in cartilage were investigated. DESIGN Full-thickness cartilage discs (d = 4.0 mm, n = 120) were detached from bovine patellae (n = 24). The diffusion of various concentrations of ioxaglate (5, 10, 21, 50 mM) and iodide (30, 60, 126, 300 mM) was allowed only through the articular surface. Samples were imaged with a clinical peripheral quantitative computed tomography scanner before immersion in contrast agent, and after 1, 5, 9, 16, 25, and 29 hours in the bath. RESULTS Diffusion and partition coefficients were similar between different contrast agent concentrations. The diffusion coefficient of iodide (473 ± 133 µm(2)/s) was greater (P ≤ 0.001) than that of ioxaglate (92 ± 46 µm(2)/s). In full-thickness cartilage, the partition coefficient (at 29 h) of iodide (71 ± 5%) was greater (P ≤ 0.02 with most concentrations) than that of ioxaglate (62 ± 6%). CONCLUSIONS Significant differences in partition and diffusion coefficient of two similarly charged (-1) contrast agents were detected, which shows the effect of steric interactions. However, the increase in solute concentration did not increase its partition coefficient. In clinical application, it is important that contrast agent concentration does not affect the interpretation of CECT imaging.
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Affiliation(s)
- Tuomo S. Silvast
- SIB-Labs, University of Eastern Finland, Kuopio, Finland,Department of Applied Physics, University of Eastern Finland, Kuopio, Finland,Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland
| | - Jukka S. Jurvelin
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Virpi Tiitu
- Institute of Biomedicine, Anatomy, University of Eastern Finland, Kuopio, Finland
| | - Thomas M. Quinn
- Department of Chemical Engineering, McGill University, Montreal, Canada
| | - Juha Töyräs
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland,Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland
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23
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Ateshian GA, Albro MB, Maas S, Weiss JA. Finite element implementation of mechanochemical phenomena in neutral deformable porous media under finite deformation. J Biomech Eng 2012; 133:081005. [PMID: 21950898 DOI: 10.1115/1.4004810] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Biological soft tissues and cells may be subjected to mechanical as well as chemical (osmotic) loading under their natural physiological environment or various experimental conditions. The interaction of mechanical and chemical effects may be very significant under some of these conditions, yet the highly nonlinear nature of the set of governing equations describing these mechanisms poses a challenge for the modeling of such phenomena. This study formulated and implemented a finite element algorithm for analyzing mechanochemical events in neutral deformable porous media under finite deformation. The algorithm employed the framework of mixture theory to model the porous permeable solid matrix and interstitial fluid, where the fluid consists of a mixture of solvent and solute. A special emphasis was placed on solute-solid matrix interactions, such as solute exclusion from a fraction of the matrix pore space (solubility) and frictional momentum exchange that produces solute hindrance and pumping under certain dynamic loading conditions. The finite element formulation implemented full coupling of mechanical and chemical effects, providing a framework where material properties and response functions may depend on solid matrix strain as well as solute concentration. The implementation was validated using selected canonical problems for which analytical or alternative numerical solutions exist. This finite element code includes a number of unique features that enhance the modeling of mechanochemical phenomena in biological tissues. The code is available in the public domain, open source finite element program FEBio (http:∕∕mrl.sci.utah.edu∕software).
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Affiliation(s)
- Gerard A Ateshian
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
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24
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Chatterjee AP. Tracer diffusion in fibre networks: the impact of spatial fluctuations in the fibre distribution. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:375103. [PMID: 21878713 DOI: 10.1088/0953-8984/23/37/375103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A mean-field formalism that addresses spatial non-uniformities in fibre networks is combined with the cylindrical cell model to calculate the diffusion constant for a spherical tracer. Deviations from randomness in the fibre distribution are described by an operational distribution over volume fractions that is parametrized by mean values for the pore radii and void space chord lengths. Weight factors for elements with different radii in the cell model are assigned in a manner that enforces agreement with the distribution over pore sizes predicted by our treatment of heterogeneous networks. Illustrative calculations suggest that the tracer diffusion constant is quite sensitive to non-uniformities in the network, particularly for tracer particles with radii that are large compared to the fibre diameter.
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Affiliation(s)
- Avik P Chatterjee
- Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
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25
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Albro MB, Li R, Banerjee RE, Hung CT, Ateshian GA. Validation of theoretical framework explaining active solute uptake in dynamically loaded porous media. J Biomech 2010; 43:2267-73. [PMID: 20553797 DOI: 10.1016/j.jbiomech.2010.04.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 04/30/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
Abstract
Solute transport in biological tissues is a fundamental process necessary for cell metabolism. In connective soft tissues, such as articular cartilage, cells are embedded within a dense extracellular matrix that hinders the transport of solutes. However, according to a recent theoretical study (Mauck et al., 2003, J. Biomech. Eng. 125, 602-614), the convective motion of a dynamically loaded porous solid matrix can also impart momentum to solutes, pumping them into the tissue and giving rise to concentrations which exceed those achived under passive diffusion alone. In this study, the theoretical predictions of this model are verified against experimental measurements. The mechanical and transport properties of an agarose-dextran model system were characterized from independent measurements and substituted into the theory to predict solute uptake or desorption under dynamic mechanical loading for various agarose concentrations and dextran molecular weights, as well as different boundary and initial conditions. In every tested case, agreement was observed between experiments and theoretical predictions as assessed by coefficients of determination ranging from R(2)=0.61 to 0.95. These results provide strong support for the hypothesis that dynamic loading of a deformable porous tissue can produce active transport of solutes via a pumping mechanisms mediated by momentum exchange between the solute and solid matrix.
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Affiliation(s)
- Michael B Albro
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
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