1
|
Pragnere S, Courtial EJ, Dubreuil F, Errazuriz-Cerda E, Marquette C, Petiot E, Pailler-Mattei C. Tuning viscoelasticity and stiffness in bioprinted hydrogels for enhanced 3D cell culture: A multi-scale mechanical analysis. J Mech Behav Biomed Mater 2024; 159:106696. [PMID: 39205347 DOI: 10.1016/j.jmbbm.2024.106696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 04/26/2024] [Accepted: 08/18/2024] [Indexed: 09/04/2024]
Abstract
Bioprinted hydrogels are extensively studied to provide an artificial matrix for 3D cell culture. The success of bioprinting hydrogels relies on fine-tuning their rheology and composition to achieve shear-thinning behavior. However, a challenge arises from the limited viscoelastic and stiffness range accessible from a single hydrogel formulation. Nevertheless, hydrogel mechanical properties are recognized as essential cues influencing cell phenotype, migration, and differentiation. Thus, it is crucial to develop a system to easily modulate bioprinted hydrogels' mechanical behaviors. In this work, we modulated the viscoelastic properties and stiffness of bioprinted hydrogels composed of fibrinogen, alginate, and gelatin by tuning the crosslinking bath solution. Various concentrations of calcium ionically crosslinked alginate, while transglutaminase crosslinked gelatin. Subsequently, we characterized the mechanical behavior of our bioprinted hydrogels from the nanoscale to the macroscale. This approach enabled the production of diverse bioprinted constructs, either with similar elastic behavior but different elastic moduli or with similar elastic moduli but different viscoelastic behavior from the same hydrogel formulation. Culturing fibroblasts in the hydrogels for 33 days revealed a preference for cell growth and matrix secretion in the viscoelastic hydrogels. This work demonstrates the suitability of the method to decouple the effects of material mechanical from biochemical composition cues on 3D cultured cells.
Collapse
Affiliation(s)
- Sarah Pragnere
- Laboratory of Tribology and System Dynamics UMR-CNRS 5513, Ecole Centrale de, Lyon, France; Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, the Netherlands
| | - Edwin-Joffrey Courtial
- 3d.FAB, Univ Lyon, Université Lyon 1, CNRS, INSA, CPE-Lyon, ICBMS, UMR 5246, 43, Bd Du 11, Villeurbanne cedex, France
| | - Frédéric Dubreuil
- Laboratory of Tribology and System Dynamics UMR-CNRS 5513, Ecole Centrale de, Lyon, France
| | | | - Christophe Marquette
- 3d.FAB, Univ Lyon, Université Lyon 1, CNRS, INSA, CPE-Lyon, ICBMS, UMR 5246, 43, Bd Du 11, Villeurbanne cedex, France
| | - Emma Petiot
- 3d.FAB, Univ Lyon, Université Lyon 1, CNRS, INSA, CPE-Lyon, ICBMS, UMR 5246, 43, Bd Du 11, Villeurbanne cedex, France
| | - Cyril Pailler-Mattei
- Laboratory of Tribology and System Dynamics UMR-CNRS 5513, Ecole Centrale de, Lyon, France; University of Lyon, Université Claude Bernard Lyon 1, ISPB-Faculté de Pharmacie de, Lyon, France.
| |
Collapse
|
2
|
López-Serrano C, Côté-Paradis Y, Habenstein B, Loquet A, Le Coz C, Ruel J, Laroche G, Durrieu MC. Integrating Mechanics and Bioactivity: A Detailed Assessment of Elasticity and Viscoelasticity at Different Scales in 2D Biofunctionalized PEGDA Hydrogels for Targeted Bone Regeneration. ACS APPLIED MATERIALS & INTERFACES 2024; 16:39165-39180. [PMID: 39041490 DOI: 10.1021/acsami.4c10755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Methods for promoting and controlling the differentiation of human mesenchymal stem cells (hMSCs) in vitro before in vivo transplantation are crucial for the advancement of tissue engineering and regenerative medicine. In this study, we developed poly(ethylene glycol) diacrylate (PEGDA) hydrogels with tunable mechanical properties, including elasticity and viscoelasticity, coupled with bioactivity achieved through the immobilization of a mixture of RGD and a mimetic peptide of the BMP-2 protein. Despite the key relevance of hydrogel mechanical properties for cell culture, a standard for its characterization has not been proposed, and comparisons between studies are challenging due to the different techniques employed. Here, a comprehensive approach was employed to characterize the elasticity and viscoelasticity of these hydrogels, integrating compression testing, rheology, and atomic force microscopy (AFM) microindentation. Distinct mechanical behaviors were observed across different PEGDA compositions, and some consistent trends across multiple techniques were identified. Using a photoactivated cross-linker, we controlled the functionalization density independently of the mechanical properties. X-ray photoelectrin spectroscopy and fluorescence microscopy were employed to evaluate the functionalization density of the materials before the culturing of hMSCs on them. The cells cultured on all functionalized hydrogels expressed an early osteoblast marker (Runx2) after 2 weeks, even in the absence of a differentiation-inducing medium compared to our controls. Additionally, after only 1 week of culture with osteogenic differentiation medium, cells showed accelerated differentiation, with clear morphological differences observed among cells in the different conditions. Notably, cells on stiff but stress-relaxing hydrogels exhibited an overexpression of the osteocyte marker E11. This suggests that the combination of the functionalization procedure with the mechanical properties of the hydrogel provides a potent approach to promoting the osteogenic differentiation of hMSCs.
Collapse
Affiliation(s)
- Cristina López-Serrano
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Pessac 33600, France
- Laboratoire d'Ingénierie de Surface, Centre de Recherche sur les Matériaux Avancés, Département de Génie des Mines, de la Métallurgie et des Matériaux, Université Laval, Québec, QC G1 V 0A6, Canada
- Axe médecine régénératrice, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, Québec, QC G1L 3L5, Canada
| | - Yeva Côté-Paradis
- Laboratoire d'Ingénierie de Surface, Centre de Recherche sur les Matériaux Avancés, Département de Génie des Mines, de la Métallurgie et des Matériaux, Université Laval, Québec, QC G1 V 0A6, Canada
- Axe médecine régénératrice, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, Québec, QC G1L 3L5, Canada
| | - Birgit Habenstein
- Univ. Bordeaux, CNRS, INSERM, IECB, US1, UAR 3033, F-33600 Pessac, France
| | - Antoine Loquet
- Univ. Bordeaux, CNRS, INSERM, IECB, US1, UAR 3033, F-33600 Pessac, France
| | - Cédric Le Coz
- Univ. Bordeaux, CNRS, Bordeaux INP, LCPO, UMR 5629, F-33600 Pessac, France
| | - Jean Ruel
- Département de Génie Mécanique, Université Laval, Québec, QC G1V 0A6, Canada
| | - Gaétan Laroche
- Laboratoire d'Ingénierie de Surface, Centre de Recherche sur les Matériaux Avancés, Département de Génie des Mines, de la Métallurgie et des Matériaux, Université Laval, Québec, QC G1 V 0A6, Canada
- Axe médecine régénératrice, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Hôpital St-François d'Assise, Québec, QC G1L 3L5, Canada
| | | |
Collapse
|
3
|
Narasimhan BN, Fraley SI. Degradability tunes ECM stress relaxation and cellular mechanics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.28.605514. [PMID: 39131364 PMCID: PMC11312499 DOI: 10.1101/2024.07.28.605514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
In native extracellular matrices (ECM), cells can use matrix metalloproteinases (MMPs) to degrade and remodel their surroundings. Likewise, synthetic matrices have been engineered to facilitate MMP-mediated cleavage that enables cell spreading, migration, and interactions. However, the intersection of matrix degradability and mechanical properties has not been fully considered. We hypothesized that immediate mechanical changes result from the action of MMPs on the ECM and that these changes are sensed by cells. Using atomic force microscopy (AFM) to measure cell-scale mechanical properties, we find that both fibrillar collagen and synthetic degradable matrices exhibit enhanced stress relaxation after MMP exposure. Cells respond to these relaxation differences by altering their spreading and focal adhesions. We demonstrate that stress relaxation can be tuned through the rational design of matrix degradability. These findings establish a fundamental link between matrix degradability and stress relaxation, which may impact a range of biological applications.
Collapse
Affiliation(s)
| | - Stephanie I. Fraley
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
4
|
Hartmann B, Fleischhauer L, Nicolau M, Jensen THL, Taran FA, Clausen-Schaumann H, Reuten R. Profiling native pulmonary basement membrane stiffness using atomic force microscopy. Nat Protoc 2024; 19:1498-1528. [PMID: 38429517 DOI: 10.1038/s41596-024-00955-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 11/27/2023] [Indexed: 03/03/2024]
Abstract
Mammalian cells sense and react to the mechanics of their immediate microenvironment. Therefore, the characterization of the biomechanical properties of tissues with high spatial resolution provides valuable insights into a broad variety of developmental, homeostatic and pathological processes within living organisms. The biomechanical properties of the basement membrane (BM), an extracellular matrix (ECM) substructure measuring only ∼100-400 nm across, are, among other things, pivotal to tumor progression and metastasis formation. Although the precise assignment of the Young's modulus E of such a thin ECM substructure especially in between two cell layers is still challenging, biomechanical data of the BM can provide information of eminent diagnostic potential. Here we present a detailed protocol to quantify the elastic modulus of the BM in murine and human lung tissue, which is one of the major organs prone to metastasis. This protocol describes a streamlined workflow to determine the Young's modulus E of the BM between the endothelial and epithelial cell layers shaping the alveolar wall in lung tissues using atomic force microscopy (AFM). Our step-by-step protocol provides instructions for murine and human lung tissue extraction, inflation of these tissues with cryogenic cutting medium, freezing and cryosectioning of the tissue samples, and AFM force-map recording. In addition, it guides the reader through a semi-automatic data analysis procedure to identify the pulmonary BM and extract its Young's modulus E using an in-house tailored user-friendly AFM data analysis software, the Center for Applied Tissue Engineering and Regenerative Medicine processing toolbox, which enables automatic loading of the recorded force maps, conversion of the force versus piezo-extension curves to force versus indentation curves, calculation of Young's moduli and generation of Young's modulus maps, where the pulmonary BM can be identified using a semi-automatic spatial filtering tool. The entire protocol takes 1-2 d.
Collapse
Affiliation(s)
- Bastian Hartmann
- Munich University of Applied Sciences, Center for Applied Tissue Engineering and Regenerative Medicine - CANTER, Munich, Germany
- Center for Nanoscience, Munich, Germany
| | - Lutz Fleischhauer
- Munich University of Applied Sciences, Center for Applied Tissue Engineering and Regenerative Medicine - CANTER, Munich, Germany
- Center for Nanoscience, Munich, Germany
| | - Monica Nicolau
- Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg, Germany
- Department of Obstetrics and Gynecology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Thomas Hartvig Lindkær Jensen
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Pathology, Rigshospitalet, Copenhagen, Denmark
| | - Florin-Andrei Taran
- Department of Obstetrics and Gynecology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Hauke Clausen-Schaumann
- Munich University of Applied Sciences, Center for Applied Tissue Engineering and Regenerative Medicine - CANTER, Munich, Germany.
- Center for Nanoscience, Munich, Germany.
| | - Raphael Reuten
- Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg, Germany.
- Department of Obstetrics and Gynecology, Medical Center, University of Freiburg, Freiburg, Germany.
| |
Collapse
|
5
|
Khalili M, Williams CJ, Micallef C, Duarte-Martinez F, Afsar A, Zhang R, Wilson S, Dossi E, Impey SA, Goel S, Aria AI. Nanoindentation Response of 3D Printed PEGDA Hydrogels in a Hydrated Environment. ACS APPLIED POLYMER MATERIALS 2023; 5:1180-1190. [PMID: 36817334 PMCID: PMC9926483 DOI: 10.1021/acsapm.2c01700] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 12/27/2022] [Indexed: 05/09/2023]
Abstract
Hydrogels are commonly used materials in tissue engineering and organ-on-chip devices. This study investigated the nanomechanical properties of monolithic and multilayered poly(ethylene glycol) diacrylate (PEGDA) hydrogels manufactured using bulk polymerization and layer-by-layer projection lithography processes, respectively. An increase in the number of layers (or reduction in layer thickness) from 1 to 8 and further to 60 results in a reduction in the elastic modulus from 5.53 to 1.69 and further to 0.67 MPa, respectively. It was found that a decrease in the number of layers induces a lower creep index (CIT) in three-dimensional (3D) printed PEGDA hydrogels. This reduction is attributed to mesoscale imperfections that appear as pockets of voids at the interfaces of the multilayered hydrogels attributed to localized regions of unreacted prepolymers, resulting in variations in defect density in the samples examined. An increase in the degree of cross-linking introduced by a higher dosage of ultraviolet (UV) exposure leads to a higher elastic modulus. This implies that the elastic modulus and creep behavior of hydrogels are governed and influenced by the degree of cross-linking and defect density of the layers and interfaces. These findings can guide an optimal manufacturing pathway to obtain the desirable nanomechanical properties in 3D printed PEGDA hydrogels, critical for the performance of living cells and tissues, which can be engineered through control of the fabrication parameters.
Collapse
Affiliation(s)
- Mohammad
Hakim Khalili
- Surface
Engineering and Precision Centre, School of Aerospace, Transport and
Manufacturing, Cranfield University, Cranfield MK43 0AL, U.K.
| | - Craig J. Williams
- The
Henry Royce Institute, Department of Materials, The University of Manchester, Manchester M13 9PL, U.K.
| | - Christian Micallef
- Surface
Engineering and Precision Centre, School of Aerospace, Transport and
Manufacturing, Cranfield University, Cranfield MK43 0AL, U.K.
| | - Fabian Duarte-Martinez
- Surface
Engineering and Precision Centre, School of Aerospace, Transport and
Manufacturing, Cranfield University, Cranfield MK43 0AL, U.K.
| | - Ashfaq Afsar
- School
of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K.
- Centre
for Defence Chemistry, Cranfield University, Shrivenham, Swindon SN6 8LA, U.K.
| | - Rujing Zhang
- Sophion
Bioscience A/S, Baltorpvej 154, 2750 Ballerup, Denmark
| | - Sandra Wilson
- Sophion
Bioscience A/S, Baltorpvej 154, 2750 Ballerup, Denmark
| | - Eleftheria Dossi
- Centre
for Defence Chemistry, Cranfield University, Shrivenham, Swindon SN6 8LA, U.K.
| | - Susan A. Impey
- Surface
Engineering and Precision Centre, School of Aerospace, Transport and
Manufacturing, Cranfield University, Cranfield MK43 0AL, U.K.
| | - Saurav Goel
- London South
Bank University, 103
Borough Road, London SE1
0AA, U.K.
- University
of Petroleum and Energy Studies, Dehradun 248007, India
| | - Adrianus Indrat Aria
- Surface
Engineering and Precision Centre, School of Aerospace, Transport and
Manufacturing, Cranfield University, Cranfield MK43 0AL, U.K.
| |
Collapse
|
6
|
Berardi M, Gnanachandran K, Jiang J, Bielawski K, Visser CW, Lekka M, Akca BI. Dynamic mechanical analysis of suspended soft bodies via hydraulic force spectroscopy. SOFT MATTER 2023; 19:615-624. [PMID: 36445288 DOI: 10.1039/d2sm01173e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The rheological characterization of soft suspended bodies, such as cells, organoids, or synthetic microstructures, is particularly challenging, even with state-of-the-art methods (e.g. atomic force microscopy, AFM). Providing well-defined boundary conditions for modeling typically requires fixating the sample on a substrate, which is a delicate and time-consuming procedure. Moreover, it needs to be tuned for each chemistry and geometry. Here, we validate a novel technique, called hydraulic force spectroscopy (HFS), against AFM dynamic indentation taken as the gold standard. Combining experimental data with finite element modeling, we show that HFS gives results comparable to AFM microrheology over multiple decades, while obviating any sample preparation requirements.
Collapse
Affiliation(s)
- Massimiliano Berardi
- LaserLab, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
- Optics11, Hettenheuvelweg 37-39, 1101 BM, Amsterdam, The Netherlands
| | - Kajangi Gnanachandran
- Department of Biophysical Microstructures, Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342, Kraków, Poland
| | - Jieke Jiang
- Engineering Fluid Dynamics group, Department of Thermal and Fluid Engineering, Faculty of Engineering Technology, University of Twente, 7500 AE, Enschede, The Netherlands
| | - Kevin Bielawski
- Optics11, Hettenheuvelweg 37-39, 1101 BM, Amsterdam, The Netherlands
| | - Claas W Visser
- Engineering Fluid Dynamics group, Department of Thermal and Fluid Engineering, Faculty of Engineering Technology, University of Twente, 7500 AE, Enschede, The Netherlands
| | - Małgorzata Lekka
- Department of Biophysical Microstructures, Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342, Kraków, Poland
| | - B Imran Akca
- LaserLab, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
| |
Collapse
|
7
|
Todros S, Spadoni S, Barbon S, Stocco E, Confalonieri M, Porzionato A, Pavan PG. Compressive Mechanical Behavior of Partially Oxidized Polyvinyl Alcohol Hydrogels for Cartilage Tissue Repair. BIOENGINEERING (BASEL, SWITZERLAND) 2022; 9:bioengineering9120789. [PMID: 36550995 PMCID: PMC9774902 DOI: 10.3390/bioengineering9120789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/06/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Polyvinyl alcohol (PVA) hydrogels are extensively used as scaffolds for tissue engineering, although their biodegradation properties have not been optimized yet. To overcome this limitation, partially oxidized PVA has been developed by means of different oxidizing agents, obtaining scaffolds with improved biodegradability. The oxidation reaction also allows tuning the mechanical properties, which are essential for effective use in vivo. In this work, the compressive mechanical behavior of native and partially oxidized PVA hydrogels is investigated, to evaluate the effect of different oxidizing agents, i.e., potassium permanganate, bromine, and iodine. For this purpose, PVA hydrogels are tested by means of indentation tests, also considering the time-dependent mechanical response. Indentation results show that the oxidation reduces the compressive stiffness from about 2.3 N/mm for native PVA to 1.1 ÷ 1.4 N/mm for oxidized PVA. During the consolidation, PVA hydrogels exhibit a force reduction of about 40% and this behavior is unaffected by the oxidizing treatment. A poroviscoelastic constitutive model is developed to describe the time-dependent mechanical response, accounting for the viscoelastic polymer matrix properties and the flow of water molecules within the matrix during long-term compression. This model allows to estimate the long-term Young's modulus of PVA hydrogels in drained conditions (66 kPa for native PVA and 34-42 kPa for oxidized PVA) and can be exploited to evaluate their performances under compressive stress in vivo, as in the case of cartilage tissue engineering.
Collapse
Affiliation(s)
- Silvia Todros
- Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy
| | - Silvia Spadoni
- Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy
- Correspondence:
| | - Silvia Barbon
- Department of Neurosciences, Section of Human Anatomy, University of Padova, via A. Gabelli 65, 35121 Padova, Italy
- L.i.f.e.L.a.b. Program, Consorzio per la Ricerca Sanitaria (CORIS), Regione Veneto, via N. Giustiniani 2, 35128 Padova, Italy
| | - Elena Stocco
- Department of Neurosciences, Section of Human Anatomy, University of Padova, via A. Gabelli 65, 35121 Padova, Italy
- L.i.f.e.L.a.b. Program, Consorzio per la Ricerca Sanitaria (CORIS), Regione Veneto, via N. Giustiniani 2, 35128 Padova, Italy
| | - Marta Confalonieri
- Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy
| | - Andrea Porzionato
- Department of Neurosciences, Section of Human Anatomy, University of Padova, via A. Gabelli 65, 35121 Padova, Italy
- L.i.f.e.L.a.b. Program, Consorzio per la Ricerca Sanitaria (CORIS), Regione Veneto, via N. Giustiniani 2, 35128 Padova, Italy
| | - Piero Giovanni Pavan
- Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy
| |
Collapse
|
8
|
Surface characterization of an ultra-soft contact lens material using an atomic force microscopy nanoindentation method. Sci Rep 2022; 12:20013. [PMID: 36411325 PMCID: PMC9678857 DOI: 10.1038/s41598-022-24701-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
As new ultra-soft materials are being developed for medical devices and biomedical applications, the comprehensive characterization of their physical and mechanical properties is both critical and challenging. To characterize the very low surface modulus of the novel biomimetic lehfilcon A silicone hydrogel contact lens coated with a layer of a branched polymer brush structure, an improved atomic force microscopy (AFM) nanoindentation method has been applied. This technique allows for precise contact-point determination without the effects of viscous squeeze-out upon approaching the branched polymer. Additionally, it allows individual brush elements to be mechanically characterized in the absence of poroelastic effects. This was accomplished by selecting an AFM probe with a design (tip size, geometry, and spring constant) that was especially suited to measuring the properties of soft materials and biological samples. The enhanced sensitivity and accuracy of this method allows for the precise measurement of the very soft lehfilcon A material, which has an extremely low elastic modulus in the surface region (as low as 2 kPa) and extremely high elasticity (nearly 100%) in an aqueous environment. The surface-characterization results not only reveal the ultra-soft nature of the lehfilcon A lens surface but also demonstrate that the elastic modulus exhibits a 30 kPa/200 nm gradient with depth due to the disparity between the modulus of the branched polymer brushes and the SiHy substrate. This surface-characterization methodology may be applied to other ultra-soft materials and medical devices.
Collapse
|
9
|
Parvini E, Hajalilou A, Lopes PA, Tiago MSM, de Almeida AT, Tavakoli M. Triple crosslinking conductive hydrogels with digitally printable and outstanding mechanical stability for high-resolution conformable bioelectronics. SOFT MATTER 2022; 18:8486-8503. [PMID: 36321471 DOI: 10.1039/d2sm01103d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Soft, conductive, and stretchable hydrogels offer a broad variety of applications, including skin-interfacing electrodes, biomonitoring patches, and electrostimulation. Despite rapid developments over the last decades, a combination of good electrical and mechanical properties, low-cost fabrication, and biocompatibility is yet to be demonstrated. Also, the current methods for deposition and patterning of these hydrogels are manual, and there is a need toward autonomous and digital fabrication techniques. In this work, we demonstrate a novel Gallium (Ga) embedded sodium-alginate-polyacrylamide-LAPONITE® (Ga-SA-PAAM-La) hydrogel, that is ultra-stretchable (Maximum strain tolerance of∼985%), tough (toughness ∼30 kJ m-3), bio-adhesive (adhesion energy ∼216 J m-2), conductive, and digitally printable. Ga nanoparticles are used as radical initiators. By adjusting the sonication parameters, we control the solution viscosity and curing time, thus allowing us to prepare pre-polymers with the desired properties for casting, or digital printing. These hydrogels benefit from a triple-network structure due to the role of Ga droplets as crosslinkers besides BIS (N,N'-methylene-bis-acrylamide) and LAPONITE®, thus resulting in tough composite hydrogels. The inclusion of LAPONITE® into the hydrogel network improved its electrical conductivity, adhesion, digital printability, and its mechanical properties, (>6× compared to the same hydrogel without LAPONITE®). As electrodes in the electrocardiogram, the signal-to-noise ratio was surprisingly higher than the medical-grade Ag/AgCl electrodes, which are applied for monitoring muscles, heart, respiration, and body joint angle through EMG, ECG, and bioimpedance measurements. The results obtained prove that such digitally printed conductive and tough hydrogels can be used as potential electrodes and sensors in practical applications in the next generation of printed wearable computing devices.
Collapse
Affiliation(s)
- Elahe Parvini
- Institute of Systems and Robotics, Department of Electrical Engineering, University of Coimbra, Coimbra, 3030-290, Portugal.
| | - Abdollah Hajalilou
- Institute of Systems and Robotics, Department of Electrical Engineering, University of Coimbra, Coimbra, 3030-290, Portugal.
| | - Pedro Alhais Lopes
- Institute of Systems and Robotics, Department of Electrical Engineering, University of Coimbra, Coimbra, 3030-290, Portugal.
| | - Miguel Soares Maranha Tiago
- Institute of Systems and Robotics, Department of Electrical Engineering, University of Coimbra, Coimbra, 3030-290, Portugal.
| | - Anibal T de Almeida
- Institute of Systems and Robotics, Department of Electrical Engineering, University of Coimbra, Coimbra, 3030-290, Portugal.
| | - Mahmoud Tavakoli
- Institute of Systems and Robotics, Department of Electrical Engineering, University of Coimbra, Coimbra, 3030-290, Portugal.
| |
Collapse
|
10
|
Symons HE, Galanti A, Surmon JC, Trask RS, Rochat S, Gobbo P. Automated analysis of soft material microindentation. SOFT MATTER 2022; 18:8302-8314. [PMID: 36286486 DOI: 10.1039/d2sm00857b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
An understanding of the mechanical properties of soft hydrogel materials over multiple length scales is important for their application in many fields. Typical measurement methods provide either bulk mechanical properties (compression, tensile, rheology) or probing of nano or microscale properties and heterogeneity (nanoindentation, AFM). In this work we demonstrate the complementarity of instrumented microindentation to these techniques, as it provides representative Young's moduli for soft materials with minimal influence of the experimental parameters chosen, and allows mechanical property mapping across macroscopic areas. To enable automated analysis of the large quantities of data required for these measurements, we develop a new fitting algorithm to process indentation data. This method allows for the determination of Young's moduli from imperfect data by automatic selection of a region of the indentation curve which does not display inelastic deformation or substrate effects. We demonstrate the applicability of our approach with a range of hydrogels, including materials with patterns and gradients in stiffness, and expect the techniques described here to be useful developments for the mechanical analysis of a wide range of soft and biological systems.
Collapse
Affiliation(s)
- Henry E Symons
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
| | - Agostino Galanti
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Giorgieri 1, 34127, Trieste, Italy.
| | - Joseph C Surmon
- Department of Aerospace Engineering and Bristol Composites Institute, School of Civil, Aerospace, and Mechanical Engineering, University of Bristol, Bristol, BS8 1TR, UK
| | - Richard S Trask
- Department of Aerospace Engineering and Bristol Composites Institute, School of Civil, Aerospace, and Mechanical Engineering, University of Bristol, Bristol, BS8 1TR, UK
| | - Sebastien Rochat
- School of Chemistry, Department of Engineering Mathematics, and Bristol Composites Institute, University of Bristol, Bristol, BS8 1TS, UK
| | - Pierangelo Gobbo
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Giorgieri 1, 34127, Trieste, Italy.
| |
Collapse
|
11
|
Xu D, Harvey T, Begiristain E, Domínguez C, Sánchez-Abella L, Browne M, Cook RB. Measuring the elastic modulus of soft biomaterials using nanoindentation. J Mech Behav Biomed Mater 2022; 133:105329. [PMID: 35753160 DOI: 10.1016/j.jmbbm.2022.105329] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 06/14/2022] [Accepted: 06/18/2022] [Indexed: 10/18/2022]
Abstract
The measurement of the elastic modulus of soft biomaterials via nanoindentation relies on the accurate determination of the zero-point of the tip-sample interaction on which the depth of penetration into the sample is based. Non-cantilever based nanoindentation systems were originally designed for hard materials, and therefore monitoring the zero-point contact presents a significant challenge for the characterisation of very soft biomaterials. This study investigates the ability of non-cantilever based nanoindentation to differentiate between hydrogels with elastic moduli on the order of single kiloPascals (kPa) using a bespoke soft contact protocol and low flexural stiffness of instrument. Polyethylene glycol (PEG) hydrogels were fabricated as a model system with a range of elastic moduli by varying the polymer concentration and degree of crosslinking. Elastic modulus values were calculated using the Oliver-Pharr method, Hertzian contact model, as well as a viscoelastic model to account for the time-dependent behaviour of the gels. The stiffness measurements were validated by measuring cantilever beams with the equivalent flexural stiffness to that of the PEG hydrogels being tested. The results demonstrated a high repeatability of the measurements, enabling differentiation between hydrogels with elastic moduli in the single kPa to hundreds of kPa range.
Collapse
Affiliation(s)
- Dichu Xu
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, SO17 1BJ, UK; Bioengineering Science Research Group, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Terence Harvey
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, SO17 1BJ, UK
| | - Eider Begiristain
- CIDETEC, Basque Research and Technology Alliance (BRTA), Parque Científico y Tecnológico de Gipuzkoa, Miramón Pasealekua, 196, Donostia-San, Sebastián, 20014, Spain
| | - Cristina Domínguez
- CIDETEC, Basque Research and Technology Alliance (BRTA), Parque Científico y Tecnológico de Gipuzkoa, Miramón Pasealekua, 196, Donostia-San, Sebastián, 20014, Spain
| | - Laura Sánchez-Abella
- CIDETEC, Basque Research and Technology Alliance (BRTA), Parque Científico y Tecnológico de Gipuzkoa, Miramón Pasealekua, 196, Donostia-San, Sebastián, 20014, Spain
| | - Martin Browne
- Bioengineering Science Research Group, University of Southampton, Southampton, SO17 1BJ, UK
| | - Richard B Cook
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, SO17 1BJ, UK
| |
Collapse
|
12
|
Ahn SY, Kim J, Vellampatti S, Oh S, Lim YT, Park SH, Luo D, Chung J, Um SH. Protein-Encoding Free-Standing RNA Hydrogel for Sub-Compartmentalized Translation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2110424. [PMID: 35263477 DOI: 10.1002/adma.202110424] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/20/2022] [Indexed: 06/14/2023]
Abstract
RNA can self-fold into complex structures that can serve as major biological regulators in protein synthesis and in catalysis. Due to the abundance of structural primitives and functional diversity, RNA has been utilized for designing nature-defined goals despite its intrinsic chemical instability and lack of technologies. Here, a robust, free-standing RNA hydrogel is developed through a sequential process involving both ligation and rolling circle transcription to form RNA G-quadruplexes, capable of both catalytic activity and enhancing expression of several proteins in sub-compartmentalized, phase-separated translation environments. The observations suggest that this hydrogel will expand RNA research and impact practical RNA principles and applications.
Collapse
Affiliation(s)
- So Yeon Ahn
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
| | - Jeonghun Kim
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
| | | | - Sung Oh
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
| | - Yong Taik Lim
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
| | - Sung Ha Park
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- Department of Physics, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
| | - Dan Luo
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, 14850, USA
| | - Junho Chung
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Soong Ho Um
- Progeneer Incorporation, 12, Digital-ro 31-gil, Guro-gu, Seoul, 08380, Korea
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
- Institute of Quantum Biophysics (IQB), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Korea
| |
Collapse
|
13
|
Schulte MF, Izak-Nau E, Braun S, Pich A, Richtering W, Göstl R. Microgels react to force: mechanical properties, syntheses, and force-activated functions. Chem Soc Rev 2022; 51:2939-2956. [PMID: 35319064 DOI: 10.1039/d2cs00011c] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microgels are colloidal polymer networks with high molar mass and properties between rigid particles, flexible macromolecules, and micellar aggregates. Their unique stimuli-responsiveness in conjunction with their colloidal phase behavior render them useful for many applications ranging from engineering to biomedicine. In many scenarios either the microgel's mechanical properties or its interactions with mechanical force play an important role. Here, we firstly explain microgel mechanical properties and how these are measured by atomic force microscopy (AFM), then we equip the reader with the synthetic background to understand how specific architectures and chemical functionalities enable these mechanical properties, and eventually we elucidate how the interaction of force with microgels can lead to the activation of latent functionality. Since the interaction of microgels with force is a multiscale and multidisciplinary subject, we introduce and interconnect the different research areas that contribute to the understanding of this emerging field in this Tutorial Review.
Collapse
Affiliation(s)
- M Friederike Schulte
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany.
| | - Emilia Izak-Nau
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
| | - Susanne Braun
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany. .,Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Andrij Pich
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany. .,Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.,Maastricht University, Aachen Maastricht Institute for Biobased Materials (AMIBM), Brightlands Chemelot Campus, 6167 RD Geleen, The Netherlands
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany.
| | - Robert Göstl
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
| |
Collapse
|
14
|
Joshi J, Homburg SV, Ehrmann A. Atomic Force Microscopy (AFM) on Biopolymers and Hydrogels for Biotechnological Applications-Possibilities and Limits. Polymers (Basel) 2022; 14:1267. [PMID: 35335597 PMCID: PMC8949482 DOI: 10.3390/polym14061267] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/15/2022] [Accepted: 03/19/2022] [Indexed: 02/01/2023] Open
Abstract
Atomic force microscopy (AFM) is one of the microscopic techniques with the highest lateral resolution. It can usually be applied in air or even in liquids, enabling the investigation of a broader range of samples than scanning electron microscopy (SEM), which is mostly performed in vacuum. Since it works by following the sample surface based on the force between the scanning tip and the sample, interactions have to be taken into account, making the AFM of irregular samples complicated, but on the other hand it allows measurements of more physical parameters than pure topography. This is especially important for biopolymers and hydrogels used in tissue engineering and other biotechnological applications, where elastic properties, surface charges and other parameters influence mammalian cell adhesion and growth as well as many other effects. This review gives an overview of AFM modes relevant for the investigations of biopolymers and hydrogels and shows several examples of recent applications, focusing on the polysaccharides chitosan, alginate, carrageenan and different hydrogels, but depicting also a broader spectrum of materials on which different AFM measurements are reported in the literature.
Collapse
Affiliation(s)
- Jnanada Joshi
- Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences, 33619 Bielefeld, Germany
| | - Sarah Vanessa Homburg
- Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences, 33619 Bielefeld, Germany
| | - Andrea Ehrmann
- Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences, 33619 Bielefeld, Germany
| |
Collapse
|
15
|
Weigel T, Malkmus C, Weigel V, Wußmann M, Berger C, Brennecke J, Groeber-Becker F, Hansmann J. Fully Synthetic 3D Fibrous Scaffolds for Stromal Tissues-Replacement of Animal-Derived Scaffold Materials Demonstrated by Multilayered Skin. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106780. [PMID: 34933407 DOI: 10.1002/adma.202106780] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/14/2021] [Indexed: 06/14/2023]
Abstract
The extracellular matrix (ECM) of soft tissues in vivo has remarkable biological and structural properties. Thereby, the ECM provides mechanical stability while it still can be rearranged via cellular remodeling during tissue maturation or healing processes. However, modern synthetic alternatives fail to provide these key features among basic properties. Synthetic matrices are usually completely degraded or are inert regarding cellular remodeling. Based on a refined electrospinning process, a method is developed to generate synthetic scaffolds with highly porous fibrous structures and enhanced fiber-to-fiber distances. Since this approach allows for cell migration, matrix remodeling, and ECM synthesis, the scaffold provides an ideal platform for the generation of soft tissue equivalents. Using this matrix, an electrospun-based multilayered skin equivalent composed of a stratified epidermis, a dermal compartment, and a subcutis is able to be generated without the use of animal matrix components. The extension of classical dense electrospun scaffolds with high porosities and motile fibers generates a fully synthetic and defined alternative to collagen-gel-based tissue models and is a promising system for the construction of tissue equivalents as in vitro models or in vivo implants.
Collapse
Affiliation(s)
- Tobias Weigel
- Translational Center for Regenerative Therapies (TLC-RT), Fraunhofer Institute for Silicate Research (ISC), 97082, Würzburg, Germany
- Department for Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, 97070, Würzburg, Germany
| | - Christoph Malkmus
- Department for Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, 97070, Würzburg, Germany
| | - Verena Weigel
- Translational Center for Regenerative Therapies (TLC-RT), Fraunhofer Institute for Silicate Research (ISC), 97082, Würzburg, Germany
- Department for Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, 97070, Würzburg, Germany
| | - Maximiliane Wußmann
- Translational Center for Regenerative Therapies (TLC-RT), Fraunhofer Institute for Silicate Research (ISC), 97082, Würzburg, Germany
| | - Constantin Berger
- Department for Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, 97070, Würzburg, Germany
| | - Julian Brennecke
- Department for Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, 97070, Würzburg, Germany
| | - Florian Groeber-Becker
- Translational Center for Regenerative Therapies (TLC-RT), Fraunhofer Institute for Silicate Research (ISC), 97082, Würzburg, Germany
- Department for Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, 97070, Würzburg, Germany
| | - Jan Hansmann
- Department for Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, 97070, Würzburg, Germany
- Faculty of Electrical Engineering, University of Applied Sciences Würzburg-Schweinfurt, 97421, Schweinfurt, Germany
| |
Collapse
|
16
|
Alhudaithy S, Hoshino K. Biocompatible micro tweezers for 3D hydrogel organoid array mechanical characterization. PLoS One 2022; 17:e0262950. [PMID: 35073389 PMCID: PMC8786121 DOI: 10.1371/journal.pone.0262950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 01/08/2022] [Indexed: 11/24/2022] Open
Abstract
This study presents novel biocompatible Polydimethylsiloxane (PDMS)-based micromechanical tweezers (μTweezers) capable of the stiffness characterization and manipulation of hydrogel-based organoids. The system showed great potential for complementing established mechanical characterization methods such as Atomic Force Microscopy (AFM), parallel plate compression (PPC), and nanoindentation, while significantly reducing the volume of valuable hydrogels used for testing. We achieved a volume reduction of ~0.22 μl/sample using the μTweezers vs. ~157 μl/sample using the PPC, while targeting high-throughput measurement of widely adopted micro-mesoscale (a few hundred μm-1500 μm) 3D cell cultures. The μTweezers applied and measured nano-millinewton forces through cantilever' deflection with high linearity and tunability for different applications; the assembly is compatible with typical inverted optical microscopes and fit on standard tissue culture Petri dishes, allowing mechanical compression characterization of arrayed 3D hydrogel-based organoids in a high throughput manner. The average achievable output per group was 40 tests per hour, where 20 organoids and 20 reference images in one 35 mm petri dish were tested, illustrating efficient productivity to match the increasing demand on 3D organoids' applications. The changes in stiffness of collagen I hydrogel organoids in four conditions were measured, with ovarian cancer cells (SKOV3) or without (control). The Young's modulus of the control group (Control-day 0, E = 407± 146, n = 4) measured by PPC was used as a reference modulus, where the relative elastic compressive modulus of the other groups based on the stiffness measurements was also calculated (control-day 0, E = 407 Pa), (SKOV3-day 0, E = 318 Pa), (control-day 5, E = 528 Pa), and (SKOV3-day 5, E = 376 Pa). The SKOV3-embedded hydrogel-based organoids had more shrinkage and lowered moduli on day 0 and day 5 than controls, consistently, while SKOV3 embedded organoids increased in stiffness in a similar trend to the collagen I control from day 0 to day 5. The proposed method can contribute to the biomedical, biochemical, and regenerative engineering fields, where bulk mechanical characterization is of interest. The μTweezers will also provide attractive design and application concepts to soft membrane-micro 3D robotics, sensors, and actuators.
Collapse
Affiliation(s)
- Soliman Alhudaithy
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States of America
- Department of Biomedical Technology, King Saud University, Riyadh, KSA
| | - Kazunori Hoshino
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States of America
| |
Collapse
|
17
|
Töpfer U, Guerra Santillán KY, Fischer-Friedrich E. Stiffness Measurement of Drosophila Egg Chambers by Atomic Force Microscopy. Methods Mol Biol 2022; 2540:301-315. [PMID: 35980585 DOI: 10.1007/978-1-0716-2541-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Drosophila egg chamber development requires cellular and molecular mechanisms controlling morphogenesis. Previous research has shown that the mechanical properties of the basement membrane contribute to tissue elongation of the egg chamber. Here, we discuss how indentation with the microindenter of an atomic force microscope can be used to determine an effective stiffness value of a Drosophila egg chamber. We provide information on the preparation of egg chambers prior to the measurement, dish coating, the actual atomic force microscope measurement process, and data analysis. Furthermore, we discuss how to interpret acquired data and which mechanical components are expected to influence measured stiffness values.
Collapse
Affiliation(s)
- Uwe Töpfer
- Institute of Genetics, Technische Universität Dresden, Dresden, Germany
| | - Karla Yanín Guerra Santillán
- Institute of Genetics, Technische Universität Dresden, Dresden, Germany
- Biotechnology Center, Technische Universität Dresden, Dresden, Germany
- Cluster of Excellence Physics of Life, Technische Universität Dresden, Dresden, Germany
| | - Elisabeth Fischer-Friedrich
- Biotechnology Center, Technische Universität Dresden, Dresden, Germany.
- Cluster of Excellence Physics of Life, Technische Universität Dresden, Dresden, Germany.
| |
Collapse
|
18
|
Quantifying force transmission through fibroblasts: changes of traction forces under external shearing. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2021; 51:157-169. [PMID: 34713316 PMCID: PMC8964583 DOI: 10.1007/s00249-021-01576-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 10/06/2021] [Accepted: 10/10/2021] [Indexed: 11/17/2022]
Abstract
Mammalian cells have evolved complex mechanical connections to their microenvironment, including focal adhesion clusters that physically connect the cytoskeleton and the extracellular matrix. This mechanical link is also part of the cellular machinery to transduce, sense and respond to external forces. Although methods to measure cell attachment and cellular traction forces are well established, these are not capable of quantifying force transmission through the cell body to adhesion sites. We here present a novel approach to quantify intracellular force transmission by combining microneedle shearing at the apical cell surface with traction force microscopy at the basal cell surface. The change of traction forces exerted by fibroblasts to underlying polyacrylamide substrates as a response to a known shear force exerted with a calibrated microneedle reveals that cells redistribute forces dynamically under external shearing and during sequential rupture of their adhesion sites. Our quantitative results demonstrate a transition from dipolar to monopolar traction patterns, an inhomogeneous distribution of the external shear force to the adhesion sites as well as dynamical changes in force loading prior to and after the rupture of single adhesion sites. Our strategy of combining traction force microscopy with external force application opens new perspectives for future studies of force transmission and mechanotransduction in cells.
Collapse
|
19
|
Kahl M, Schneidereit D, Bock N, Friedrich O, Hutmacher DW, Meinert C. MechAnalyze: An Algorithm for Standardization and Automation of Compression Test Analysis. Tissue Eng Part C Methods 2021; 27:529-542. [PMID: 34541882 DOI: 10.1089/ten.tec.2021.0170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The mechanical properties of hydrogels, as well as native and engineered tissues are key parameters frequently assessed in biomaterial science and tissue engineering research. However, a lack of standardized methods and user-independent data analysis has impacted the research community for many decades and contributes to poor reproducibility and comparability of datasets, representing a significant issue often neglected in publications. In this study, we provide a software package, MechAnalyze, facilitating the standardized and automated analysis of force-displacement data generated in unconfined compression tests. Using comparative studies of datasets analyzed manually and with MechAnalyze, we demonstrate that the software reliably determines the compressive moduli, failure stress and failure strain of hydrogels, as well as engineered and native tissues, while providing an intuitive user interface that requires minimal user input. MechAnalyze provides a fast and user-independent data analysis method and advances process standardization, reproducibility, and comparability of data for the mechanical characterization of biomaterials as well as native and engineered tissues. Impact statement Mechanical properties of hydrogels are crucial parameters in the development of new materials for tissue engineering. However, manual assessment is tedious, not standardized and suffers under user-to-user bias. Hence, the here presented stand-alone software package provides analysis and statistics of force-displacement and material geometry data to determine the compressive moduli, failure stress, and failure strain in a standardized, robust, and automated fashion. MechAnalyze will substantially support biomechanical testing of hydrogels as well as engineered and native tissues and will thus, be of appreciable value to a broad target group in regenerative medicine, tissue engineering, but also life sciences and biomedicine.
Collapse
Affiliation(s)
- Melanie Kahl
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.,Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,Faculty of Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Dominik Schneidereit
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Nathalie Bock
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,Faculty of Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia.,Translational Research Institute, Queensland University of Technology, Woolloongabba, Australia
| | - Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.,Centre for Biomedical Technologies, Science and Engineering Faculty, School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, Australia
| | - Dietmar W Hutmacher
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,Faculty of Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia.,Centre for Biomedical Technologies, Science and Engineering Faculty, School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, Australia.,ARC ITTC in Additive Biomanufacturing, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,ARC Training Centre for Cell and Tissue Engineering Technologies, Queensland University of Technology, Brisbane, Australia
| | - Christoph Meinert
- Centre in Regenerative Medicine, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,Centre for Biomedical Technologies, Science and Engineering Faculty, School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, Australia.,Herston Biofabrication Institute, Metro North Hospital and Health Services, Brisbane, Australia
| |
Collapse
|
20
|
Marin-Tapia HA, Romero-Salazar L, Arteaga-Arcos JC, Rosales-Ibáñez R, Mayorga-Rojas M. Micro-mechanical properties of corneal scaffolds from two different bio-models obtained by an efficient chemical decellularization. J Mech Behav Biomed Mater 2021; 119:104510. [PMID: 33872923 DOI: 10.1016/j.jmbbm.2021.104510] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 03/12/2021] [Accepted: 04/03/2021] [Indexed: 10/21/2022]
Abstract
The present study elucidates the impact of detergent-based chemical decellularization on the micro-mechanical properties of porcine and rabbit corneas for the purpose of extracellular matrix (ECM) derived scaffolds. Aiming to optimize the decellularization process, different concentrations of Sodium Dodecyl Sulfate (SDS), Triton X-100 and CHAPS detergents were assessed on their ability to decellularize corneas from both bio-models at incubation periods of 12 and 24h. We evaluated the effect of decellularization on corneal ECM Young's Modulus and various area's roughness parameters (topography features) at a microscale by using Atomic Force Microscopy (AFM). Only SDS presented adequate decellularization properties at the selected concentrations (0.2, 0.5 and 1%) and incubation periods. All topography features displayed by native corneas were preserved after SDS treatments, while no statistically significant differences were identified for the average value of Young's Modulus between the control samples and those treated with 0.2% SDS (rabbit corneas) and 0.5% SDS (porcine corneas) after 12h. In this sense, cornea decellularization procedures can be improved by simultaneously reducing SDS concentration and incubation period. AFM is a useful tool to perform biomechanical analysis of the effect of decellularization on scaffold micro-mechanics. Evaluation of the scaffold mechanical behavior at a microscale could help in understanding cell-scaffold interactions in terms of mechanotransduction, complementing macroscale techniques (e.g. tensile tests) relevant for tissue engineering quality control and decision-making.
Collapse
Affiliation(s)
- Hugo Arian Marin-Tapia
- Rheology, Nanofluids and Microfluidics Laboratory, Autonomous University of the State of Mexico, Faculty of Sciences, Campus Universitario ''El Cerrillo, Piedras Blancas", Carretera Toluca-Ixtlahuaca km 15.5, C.P. 50200 Estado de México, Mexico; Autonomous University of the State of Mexico, Faculty of Sciences, Campus Universitario ''El Cerrillo, Piedras Blancas", Carretera Toluca-Ixtlahuaca km 15.5, C.P. 50200 Estado de México, Mexico.
| | - Lorena Romero-Salazar
- Nanothermodynamics and Complex Systems Laboratory, Autonomous University of the State of Mexico, Faculty of Sciences, Campus Universitario ''El Cerrillo, Piedras Blancas", Carretera Toluca-Ixtlahuaca km 15.5, C.P. 50200 Estado de México, Mexico.
| | - Juan Carlos Arteaga-Arcos
- Micromechanics Laboratory, Autonomous University of the State of Mexico, Faculty of Sciences, Instituto Literario, No. 100 Ote., C.P, 50000, Toluca, State of Mexico, Mexico.
| | - Raúl Rosales-Ibáñez
- Tissue Engineering and Translational Medicine Laboratory, Faculty of Higher Studies (FES) Iztacala, National Autonomous University of Mexico, Tlalnepantla, 54090, Mexico City, Mexico.
| | - Miguel Mayorga-Rojas
- Rheology, Nanofluids and Microfluidics Laboratory, Autonomous University of the State of Mexico, Faculty of Sciences, Campus Universitario ''El Cerrillo, Piedras Blancas", Carretera Toluca-Ixtlahuaca km 15.5, C.P. 50200 Estado de México, Mexico.
| |
Collapse
|
21
|
Zaman R, Lombardo A, Sauvanet C, Viswanatha R, Awad V, Bonomo LER, McDermitt D, Bretscher A. Effector-mediated ERM activation locally inhibits RhoA activity to shape the apical cell domain. J Cell Biol 2021; 220:211973. [PMID: 33836044 PMCID: PMC8185690 DOI: 10.1083/jcb.202007146] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 02/07/2021] [Accepted: 03/09/2021] [Indexed: 12/21/2022] Open
Abstract
Activated ezrin-radixin-moesin (ERM) proteins link the plasma membrane to the actin cytoskeleton to generate apical structures, including microvilli. Among many kinases implicated in ERM activation are the homologues LOK and SLK. CRISPR/Cas9 was used to knock out all ERM proteins or LOK/SLK in human cells. LOK/SLK knockout eliminates all ERM-activating phosphorylation. The apical domains of cells lacking LOK/SLK or ERMs are strikingly similar and selectively altered, with loss of microvilli and with junctional actin replaced by ectopic myosin-II–containing apical contractile structures. Constitutively active ezrin can reverse the phenotypes of either ERM or LOK/SLK knockouts, indicating that a central function of LOK/SLK is to activate ERMs. Both knockout lines have elevated active RhoA with concomitant enhanced myosin light chain phosphorylation, revealing that active ERMs are negative regulators of RhoA. As RhoA-GTP activates LOK/SLK to activate ERM proteins, the ability of active ERMs to negatively regulate RhoA-GTP represents a novel local feedback loop necessary for the proper apical morphology of epithelial cells.
Collapse
Affiliation(s)
- Riasat Zaman
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Andrew Lombardo
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Cécile Sauvanet
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Raghuvir Viswanatha
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Valerie Awad
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Locke Ezra-Ros Bonomo
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - David McDermitt
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Anthony Bretscher
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| |
Collapse
|
22
|
Liamas E, Connell SD, Zembyla M, Ettelaie R, Sarkar A. Friction between soft contacts at nanoscale on uncoated and protein-coated surfaces. NANOSCALE 2021; 13:2350-2367. [PMID: 33367416 DOI: 10.1039/d0nr06527g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The understanding of friction on soft sliding biological surfaces at the nanoscale is poorly understood as hard interfaces are frequently used as model systems. Herein, we studied the influence of elastic modulus on the frictional properties of model surfaces at the nanoscale for the first time. We prepared model silicone-based elastomer surfaces with tuneable modulus ranging from hundreds of kPa to a few MPa, similar to those found in real biological surfaces, and employed atomic force microscopy to characterize their modulus, adhesion, and surface morphology. Consequently, we used friction force microscopy to investigate nanoscale friction in hard-soft and soft-soft contacts using spherical colloidal probes covered by adsorbed protein films. Unprecedented results from this study reveal that modulus of a surface can have a significant impact on the frictional properties of protein-coated surfaces with higher deformability leading to lower contact pressure and, consequently, decreased friction. These important results pave the way forward for designing new functional surfaces for serving as models of appropriate deformability to replicate the mechanical properties of the biological structures and processes for accurate friction measurements at nanoscale.
Collapse
Affiliation(s)
- Evangelos Liamas
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| | - Simon D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, UK.
| | - Morfo Zembyla
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| | - Rammile Ettelaie
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
| |
Collapse
|
23
|
Louf JF, Lu NB, O'Connell MG, Cho HJ, Datta SS. Under pressure: Hydrogel swelling in a granular medium. SCIENCE ADVANCES 2021; 7:7/7/eabd2711. [PMID: 33579709 PMCID: PMC7880600 DOI: 10.1126/sciadv.abd2711] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/23/2020] [Indexed: 05/28/2023]
Abstract
Hydrogels hold promise in agriculture as reservoirs of water in dry soil, potentially alleviating the burden of irrigation. However, confinement in soil can markedly reduce the ability of hydrogels to absorb water and swell, limiting their widespread adoption. Unfortunately, the underlying reason remains unknown. By directly visualizing the swelling of hydrogels confined in three-dimensional granular media, we demonstrate that the extent of hydrogel swelling is determined by the competition between the force exerted by the hydrogel due to osmotic swelling and the confining force transmitted by the surrounding grains. Furthermore, the medium can itself be restructured by hydrogel swelling, as set by the balance between the osmotic swelling force, the confining force, and intergrain friction. Together, our results provide quantitative principles to predict how hydrogels behave in confinement, potentially improving their use in agriculture as well as informing other applications such as oil recovery, construction, mechanobiology, and filtration.
Collapse
Affiliation(s)
- Jean-François Louf
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Nancy B Lu
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Margaret G O'Connell
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - H Jeremy Cho
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
- Department of Mechanical Engineering, University of Nevada, Las Vegas, NV 89154, USA
| | - Sujit S Datta
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
| |
Collapse
|