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Sebastian JA, Strohm EM, Baranger J, Villemain O, Kolios MC, Simmons CA. Assessing engineered tissues and biomaterials using ultrasound imaging: In vitro and in vivo applications. Biomaterials 2023; 296:122054. [PMID: 36842239 DOI: 10.1016/j.biomaterials.2023.122054] [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: 07/12/2022] [Revised: 01/24/2023] [Accepted: 02/11/2023] [Indexed: 02/18/2023]
Abstract
Quantitative assessment of the structural, functional, and mechanical properties of engineered tissues and biomaterials is fundamental to their development for regenerative medicine applications. Ultrasound (US) imaging is a non-invasive, non-destructive, and cost-effective technique capable of longitudinal and quantitative monitoring of tissue structure and function across centimeter to sub-micron length scales. Here we present the fundamentals of US to contextualize its application for the assessment of biomaterials and engineered tissues, both in vivo and in vitro. We review key studies that demonstrate the versatility and broad capabilities of US for clinical and pre-clinical biomaterials research. Finally, we highlight emerging techniques that further extend the applications of US, including for ultrafast imaging of biomaterials and engineered tissues in vivo and functional monitoring of stem cells, organoids, and organ-on-a-chip systems in vitro.
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Affiliation(s)
- Joseph A Sebastian
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada.
| | - Eric M Strohm
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada
| | - Jérôme Baranger
- Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Olivier Villemain
- Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Michael C Kolios
- Department of Physics, Toronto Metropolitan University, Toronto, Canada; Institute of Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Canada
| | - Craig A Simmons
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.
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Sebastian JA, Strohm EM, Chérin E, Mirani B, Démoré CEM, Kolios MC, Simmons CA. High-frequency quantitative ultrasound for the assessment of the acoustic properties of engineered tissues in vitro. Acta Biomater 2023; 157:288-296. [PMID: 36521676 DOI: 10.1016/j.actbio.2022.12.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 11/07/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022]
Abstract
Acoustic properties of biomaterials and engineered tissues reflect their structure and cellularity. High-frequency ultrasound (US) can non-invasively characterize and monitor these properties with sub-millimetre resolution. We present an approach to estimate the speed of sound, acoustic impedance, and acoustic attenuation of cell-laden hydrogels that accounts for frequency-dependent effects of attenuation in coupling media, hydrogel thickness, and interfacial transmission/reflection coefficients of US waves, all of which can bias attenuation estimates. Cell-seeded fibrin hydrogel disks were raster-scanned using a 40 MHz US transducer. Thickness, speed of sound, acoustic impedance, and acoustic attenuation coefficients were determined from the difference in the time-of-flight and ratios of the magnitudes of US signals, interfacial transmission/reflection coefficients, and acoustic properties of the coupling media. With this approach, hydrogel thickness was accurately measured by US, with agreement to confocal microscopy (r2 = 0.97). Accurate thickness measurement enabled acoustic property measurements that were independent of hydrogel thickness, despite up to 60% reduction in thickness due to cell-mediated contraction. Notably, acoustic attenuation coefficients increased with increasing cell concentration (p < 0.001), reflecting hydrogel cellularity independent of contracted hydrogel thickness. This approach enables accurate measurement of the intrinsic acoustic properties of biomaterials and engineered tissues to provide new insights into their structure and cellularity. STATEMENT OF SIGNIFICANCE: High-frequency ultrasound can measure the acoustic properties of engineered tissues non-invasively and non-destructively with µm-scale resolution. Acoustic properties, including acoustic attenuation, are related to intrinsic material properties, such as scatterer density. We developed an analytical approach to estimate the acoustic properties of cell-laden hydrogels that accounts for the frequency-dependent effects of attenuation in coupling media, the reflection/transmission of ultrasound waves at the coupling interfaces, and the dependency of measurements on hydrogel thickness. Despite up to 60% reduction in hydrogel thickness due to cell-mediated contraction, our approach enabled measurements of acoustic properties that were substantially independent of thickness. Acoustic attenuation increased significantly with increasing cell concentration (p < 0.001), demonstrating the ability of acoustic attenuation to reflect intrinsic physical properties of engineered tissues.
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Affiliation(s)
- Joseph A Sebastian
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada.
| | - Eric M Strohm
- Department of Physics, Toronto Metropolitan University, Toronto, Canada; Institute of Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Canada
| | | | - Bahram Mirani
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada
| | - Christine E M Démoré
- Sunnybrook Research Institute, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Michael C Kolios
- Department of Physics, Toronto Metropolitan University, Toronto, Canada; Institute of Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Canada
| | - Craig A Simmons
- Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.
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Li L, Zhang X, Zhou J, Zhang L, Xue J, Tao W. Non-Invasive Thermal Therapy for Tissue Engineering and Regenerative Medicine. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2107705. [PMID: 35475541 DOI: 10.1002/smll.202107705] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 03/11/2022] [Indexed: 06/14/2023]
Abstract
Owing to the development of nanotechnology and noninvasive treatment, thermal therapy in combination with external stimuli has been applied for tissue engineering and regenerative medicine (TERM), which has attracted more and more attention in recent years. In this review, the recent progress of applying a variety of non-invasive thermal therapeutic modalities for TERM, including photothermal therapy, magnetic thermotherapy, and ultrasound thermotherapy, as well as other thermal therapeutics are discussed. The parameters and conditions that need to be considered and regulated to realize a well-controlled thermal therapy for tissue regeneration are also discussed. Afterwards, the current concerns and challenges of putting thermal therapy into clinical applications are pointed out. At last, perspectives are provided for the future development directions, aiming to providing opportunities and a novel pathway for TERM.
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Affiliation(s)
- Longfei Li
- Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Xiaodi Zhang
- Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, United States
| | - Jun Zhou
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, United States
| | - Liqun Zhang
- Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Jiajia Xue
- Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Wei Tao
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, United States
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Guo T, He C, Venado A, Zhou Y. Extracellular Matrix Stiffness in Lung Health and Disease. Compr Physiol 2022; 12:3523-3558. [PMID: 35766837 PMCID: PMC10088466 DOI: 10.1002/cphy.c210032] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The extracellular matrix (ECM) provides structural support and imparts a wide variety of environmental cues to cells. In the past decade, a growing body of work revealed that the mechanical properties of the ECM, commonly known as matrix stiffness, regulate the fundamental cellular processes of the lung. There is growing appreciation that mechanical interplays between cells and associated ECM are essential to maintain lung homeostasis. Dysregulation of ECM-derived mechanical signaling via altered mechanosensing and mechanotransduction pathways is associated with many common lung diseases. Matrix stiffening is a hallmark of lung fibrosis. The stiffened ECM is not merely a sequelae of lung fibrosis but can actively drive the progression of fibrotic lung disease. In this article, we provide a comprehensive view on the role of matrix stiffness in lung health and disease. We begin by summarizing the effects of matrix stiffness on the function and behavior of various lung cell types and on regulation of biomolecule activity and key physiological processes, including host immune response and cellular metabolism. We discuss the potential mechanisms by which cells probe matrix stiffness and convert mechanical signals to regulate gene expression. We highlight the factors that govern matrix stiffness and outline the role of matrix stiffness in lung development and the pathogenesis of pulmonary fibrosis, pulmonary hypertension, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. We envision targeting of deleterious matrix mechanical cues for treatment of fibrotic lung disease. Advances in technologies for matrix stiffness measurements and design of stiffness-tunable matrix substrates are also explored. © 2022 American Physiological Society. Compr Physiol 12:3523-3558, 2022.
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Affiliation(s)
- Ting Guo
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Alabama, USA.,Department of Respiratory Medicine, the Second Xiangya Hospital, Central-South University, Changsha, Hunan, China
| | - Chao He
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Alabama, USA
| | - Aida Venado
- Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California, USA
| | - Yong Zhou
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Alabama, USA
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Constitutive Equations for Analyzing Stress Relaxation and Creep of Viscoelastic Materials Based on Standard Linear Solid Model Derived with Finite Loading Rate. Polymers (Basel) 2022; 14:polym14102124. [PMID: 35632006 PMCID: PMC9143375 DOI: 10.3390/polym14102124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 02/06/2023] Open
Abstract
The viscoelastic properties of materials such as polymers can be quantitatively evaluated by measuring and analyzing the viscoelastic behaviors such as stress relaxation and creep. The standard linear solid model is a classical and commonly used mathematical model for analyzing stress relaxation and creep behaviors. Traditionally, the constitutive equations for analyzing stress relaxation and creep behaviors based on the standard linear solid model are derived using the assumption that the loading is a step function, implying that the loading rate used in the loading process of stress relaxation and creep tests is infinite. Using such constitutive equations may cause significant errors in analyses since the loading rate must be finite (no matter how fast it is) in a real stress relaxation or creep experiment. The purpose of this paper is to introduce the constitutive equations for analyzing stress relaxation and creep behaviors based on the standard linear solid model derived with a finite loading rate. The finite element computational simulation results demonstrate that the constitutive equations derived with a finite loading rate can produce accurate results in the evaluation of all viscoelastic parameters regardless of the loading rate in most cases. It is recommended that the constitutive equations derived with a finite loading rate should replace the traditional ones derived with an infinite loading rate to analyze stress relaxation and creep behaviors for quantitatively evaluating the viscoelastic properties of materials.
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Duan X, Li N, Chen X, Zhu N. Characterization of Tissue Scaffolds Using Synchrotron Radiation Microcomputed Tomography Imaging. Tissue Eng Part C Methods 2021; 27:573-588. [PMID: 34670397 DOI: 10.1089/ten.tec.2021.0155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Distinguishing from other traditional imaging, synchrotron radiation microcomputed tomography (SR-μCT) imaging allows for the visualization of three-dimensional objects of interest in a nondestructive and/or in situ way with better spatial resolution, deep penetration, relatively fast speed, and/or high contrast. SR-μCT has been illustrated promising for visualizing and characterizing tissue scaffolds for repairing or replacing damaged tissue or organs in tissue engineering (TE), which is of particular advance for longitudinal monitoring and tracking the success of scaffolds once implanted in animal models and/or human patients. This article presents a comprehensive review on recent studies of characterization of scaffolds based on SR-μCT and takes scaffold architectural properties, mechanical properties, degradation, swelling and wettability, and biological properties as five separate sections to introduce SR-μCT wide applications. We also discuss and highlight the unique opportunities of SR-μCT in various TE applications; conclude this article with the suggested future research directions, including the prospective applications of SR-μCT, along with its challenges and methods for improvement in the field of TE.
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Affiliation(s)
- Xiaoman Duan
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Naitao Li
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Xiongbiao Chen
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
- Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Ning Zhu
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
- Department of Chemical and Biological Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
- Canadian Light Source, Saskatoon, Canada
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Valera-Calero JA, Úbeda-D'Ocasar E, Caballero-Corella M, Fernández-de-Las-Peñas C, Sendarrubias GMG, Arias-Buría JL. Cervical Multifidus Morphology and Quality is not Associated with Clinical Variables in Women with Fibromyalgia: An Observational Study. PAIN MEDICINE 2021; 23:1138-1143. [PMID: 34633451 DOI: 10.1093/pm/pnab297] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 10/01/2021] [Accepted: 10/06/2021] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Some studies have reported the presence of histological alterations such as myofibers disorganization and abnormalities in the number and shape of mitochondria in patients with fibromyalgia syndrome (FMS). Although Ultrasound imaging (US) is used to quantitatively characterize muscle tissues, US studies in patients with FMS are lacking. Therefore, we aimed to describe morphological and qualitative cervical multifidus (CM) muscle US features in women with FMS and to assess their correlation with clinical indicators. DESIGN Observational study. SETTING AFINSYFACRO Fibromyalgia Association (Madrid, Spain). SUBJECTS Forty-five women with FMS participated. METHODS Sociodemographic (e.g., age, height, weight, and BMI), clinical (e.g., pain -NPRS-, evolution time, related-disability -FIQ-) outcomes were collected. Images were acquired bilaterally at the cervical spine (C4-C5 level) and measured by an experienced examiner for assessing muscle morphology (e.g., cross-sectional area -CSA-, perimeter and shape) and quality (mean echo-intensity -EI- and intramuscular fatty infiltration -FI-). Side-to-side comparisons and a correlational analysis were conducted. RESULTS No significant side-to-side differences were found for morphology nor quality features (P > 0.05). None of the clinical indicators were associated with US characteristics (all, P > 0.05). CONCLUSION Our results showed no side-to-side differences for CM morphology and quality as assessed with US. No associations between CM muscle morphology nor quality with FIQ, PPT, NPRS nor evolution time were observed. Our preliminary data suggest that muscle morphology is not directly related to pain and related-disability in women with FMS.
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Affiliation(s)
| | - Edurne Úbeda-D'Ocasar
- Department of Physical Therapy, Universidad Camilo José Cela, Villanueva de la Cañada, Madrid, Spain
| | - Mario Caballero-Corella
- Department of Physical Therapy, Universidad Camilo José Cela, Villanueva de la Cañada, Madrid, Spain
| | - Cesar Fernández-de-Las-Peñas
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, Alcorcón, Spain.,Cátedra Institucional en Docencia, Clínica e Investigación en Fisioterapia: Terapia Manual, Punción Seca y Ejercicio Terapéutico, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain
| | | | - José Luis Arias-Buría
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, Alcorcón, Spain.,Cátedra Institucional en Docencia, Clínica e Investigación en Fisioterapia: Terapia Manual, Punción Seca y Ejercicio Terapéutico, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain
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Lin CY, Kang JH. Mechanical Properties of Compact Bone Defined by the Stress-Strain Curve Measured Using Uniaxial Tensile Test: A Concise Review and Practical Guide. MATERIALS (BASEL, SWITZERLAND) 2021; 14:4224. [PMID: 34361418 PMCID: PMC8347989 DOI: 10.3390/ma14154224] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 12/03/2022]
Abstract
Mechanical properties are crucial parameters for scaffold design for bone tissue engineering; therefore, it is important to understand the definitions of the mechanical properties of bones and relevant analysis methods, such that tissue engineers can use this information to properly design the mechanical properties of scaffolds for bone tissue engineering. The main purpose of this article is to provide a review and practical guide to understand and analyze the mechanical properties of compact bone that can be defined and extracted from the stress-strain curve measured using uniaxial tensile test until failure. The typical stress-strain curve of compact bone measured using uniaxial tensile test until failure is a bilinear, monotonically increasing curve. The associated mechanical properties can be obtained by analyzing this bilinear stress-strain curve. In this article, a computer programming code for analyzing the bilinear stress-strain curve of compact bone for quantifying the associated mechanical properties is provided, such that the readers can use this computer code to perform the analysis directly. In addition to being applied to compact bone, the information provided by this article can also be applied to quantify the mechanical properties of any material having a bilinear stress-strain curve, such as a whole bone, some metals and biomaterials. The information provided by this article can be applied by tissue engineers, such that they can have a reference to properly design the mechanical properties of scaffolds for bone tissue engineering. The information can also be applied by researchers in biomechanics and orthopedics to compare the mechanical properties of bones in different physiological or pathological conditions.
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Affiliation(s)
- Che-Yu Lin
- Institute of Applied Mechanics, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Jiunn-Horng Kang
- Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, 252 Wuxing Str., Taipei 11031, Taiwan
- Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Str., Taipei 11031, Taiwan
- Research Center of Artificial Intelligence in Medicine, Taipei Medical University, 250 Wuxing Str., Taipei 11031, Taiwan
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Effects of Loading and Boundary Conditions on the Performance of Ultrasound Compressional Viscoelastography: A Computational Simulation Study to Guide Experimental Design. MATERIALS 2021; 14:ma14102590. [PMID: 34065764 PMCID: PMC8156541 DOI: 10.3390/ma14102590] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/10/2021] [Accepted: 05/12/2021] [Indexed: 01/01/2023]
Abstract
Most biomaterials and tissues are viscoelastic; thus, evaluating viscoelastic properties is important for numerous biomedical applications. Compressional viscoelastography is an ultrasound imaging technique used for measuring the viscoelastic properties of biomaterials and tissues. It analyzes the creep behavior of a material under an external mechanical compression. The aim of this study is to use finite element analysis to investigate how loading conditions (the distribution of the applied compressional pressure on the surface of the sample) and boundary conditions (the fixation method used to stabilize the sample) can affect the measurement accuracy of compressional viscoelastography. The results show that loading and boundary conditions in computational simulations of compressional viscoelastography can severely affect the measurement accuracy of the viscoelastic properties of materials. The measurement can only be accurate if the compressional pressure is exerted on the entire top surface of the sample, as well as if the bottom of the sample is fixed only along the vertical direction. These findings imply that, in an experimental validation study, the phantom design should take into account that the surface area of the pressure plate must be equal to or larger than that of the top surface of the sample, and the sample should be placed directly on the testing platform without any fixation (such as a sample container). The findings indicate that when applying compressional viscoelastography to real tissues in vivo, consideration should be given to the representative loading and boundary conditions. The findings of the present simulation study will provide a reference for experimental phantom designs regarding loading and boundary conditions, as well as guidance towards validating the experimental results of compressional viscoelastography.
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Berry DB, Englund EK, Chen S, Frank LR, Ward SR. Medical imaging of tissue engineering and regenerative medicine constructs. Biomater Sci 2021; 9:301-314. [PMID: 32776044 PMCID: PMC8262082 DOI: 10.1039/d0bm00705f] [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] [Indexed: 12/13/2022]
Abstract
Advancement of tissue engineering and regenerative medicine (TERM) strategies to replicate tissue structure and function has led to the need for noninvasive assessment of key outcome measures of a construct's state, biocompatibility, and function. Histology based approaches are traditionally used in pre-clinical animal experiments, but are not always feasible or practical if a TERM construct is going to be tested for human use. In order to transition these therapies from benchtop to bedside, rigorously validated imaging techniques must be utilized that are sensitive to key outcome measures that fulfill the FDA standards for TERM construct evaluation. This review discusses key outcome measures for TERM constructs and various clinical- and research-based imaging techniques that can be used to assess them. Potential applications and limitations of these techniques are discussed, as well as resources for the processing, analysis, and interpretation of biomedical images.
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Affiliation(s)
- David B Berry
- Departments of NanoEngineering, University of California, San Diego, USA.
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11
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Sorriento A, Poliziani A, Cafarelli A, Valenza G, Ricotti L. A novel quantitative and reference-free ultrasound analysis to discriminate different concentrations of bone mineral content. Sci Rep 2021; 11:301. [PMID: 33432022 PMCID: PMC7801603 DOI: 10.1038/s41598-020-79365-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 12/07/2020] [Indexed: 12/19/2022] Open
Abstract
Bone fracture is a continuous process, during which bone mineral matrix evolves leading to an increase in hydroxyapatite and calcium carbonate content. Currently, no gold standard methods are available for a quantitative assessment of bone fracture healing. Moreover, the available tools do not provide information on bone composition. Whereby, there is a need for objective and non-invasive methods to monitor the evolution of bone mineral content. In general, ultrasound can guarantee a quantitative characterization of tissues. However, previous studies required measurements on reference samples. In this paper we propose a novel and reference-free parameter, based on the entropy of the phase signal calculated from the backscattered data in combination with amplitude information, to also consider absorption and scattering phenomena. The proposed metric was effective in discriminating different hydroxyapatite (from 10 to 50% w/v) and calcium carbonate (from 2 to 6% w/v) concentrations in bone-mimicking phantoms without the need for reference measurements, paving the way to their translational use for the diagnosis of tissue healing. To the best of our knowledge this is the first time that the phase entropy of the backscattered ultrasound signals is exploited for monitoring changes in the mineral content of bone-like materials.
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Affiliation(s)
- A Sorriento
- The BioRobotics Institute, Scuola Superiore Sant'Anna, 56127, Pisa, Italy.
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, 56127, Pisa, Italy.
| | - A Poliziani
- The BioRobotics Institute, Scuola Superiore Sant'Anna, 56127, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, 56127, Pisa, Italy
| | - A Cafarelli
- The BioRobotics Institute, Scuola Superiore Sant'Anna, 56127, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, 56127, Pisa, Italy
| | - G Valenza
- Bioengineerring and Robotics Research Centre E Piaggio, University of Pisa, 56122, Pisa, Italy
- Department of Information Engineering, University of Pisa, 56123, Pisa, Italy
| | - L Ricotti
- The BioRobotics Institute, Scuola Superiore Sant'Anna, 56127, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, 56127, Pisa, Italy
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Mercuri M, Fernandez Rivas D. Challenges and opportunities for small volumes delivery into the skin. BIOMICROFLUIDICS 2021; 15:011301. [PMID: 33532017 PMCID: PMC7826167 DOI: 10.1063/5.0030163] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 01/09/2021] [Indexed: 05/04/2023]
Abstract
Each individual's skin has its own features, such as strength, elasticity, or permeability to drugs, which limits the effectiveness of one-size-fits-all approaches typically found in medical treatments. Therefore, understanding the transport mechanisms of substances across the skin is instrumental for the development of novel minimal invasive transdermal therapies. However, the large difference between transport timescales and length scales of disparate molecules needed for medical therapies makes it difficult to address fundamental questions. Thus, this lack of fundamental knowledge has limited the efficacy of bioengineering equipment and medical treatments. In this article, we provide an overview of the most important microfluidics-related transport phenomena through the skin and versatile tools to study them. Moreover, we provide a summary of challenges and opportunities faced by advanced transdermal delivery methods, such as needle-free jet injectors, microneedles, and tattooing, which could pave the way to the implementation of better therapies and new methods.
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Affiliation(s)
- Magalí Mercuri
- Instituto de Nanociencia y Nanotecnología (CNEA-CONICET), Av. Gral. Paz 1499, 1650 San Martín, Buenos Aires, Argentina
| | - David Fernandez Rivas
- Mesoscale Chemical Systems Group, MESA+ Institute, TechMed Centre and Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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13
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Gnyawali SC, Sinha M, El Masry MS, Wulff B, Ghatak S, Soto-Gonzalez F, Wilgus TA, Roy S, Sen CK. High resolution ultrasound imaging for repeated measure of wound tissue morphometry, biomechanics and hemodynamics under fetal, adult and diabetic conditions. PLoS One 2020; 15:e0241831. [PMID: 33227015 PMCID: PMC7682876 DOI: 10.1371/journal.pone.0241831] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 10/21/2020] [Indexed: 02/07/2023] Open
Abstract
Non-invasive, repeated interrogation of the same wound is necessary to understand the tissue repair continuum. In this work, we sought to test the significance of non-invasive high-frequency high-resolution ultrasound technology for such interrogation. High-frequency high-resolution ultrasound imaging was employed to investigate wound healing under fetal and adult conditions. Quantitative tissue cellularity and elastic strain was obtained for visualization of unresolved inflammation using Vevo strain software. Hemodynamic properties of the blood flow in the artery supplying the wound-site were studied using color Doppler flow imaging. Non-invasive monitoring of fetal and adult wound healing provided unprecedented biomechanical and functional insight. Fetal wounds showed highly accelerated closure with transient perturbation of wound tissue cellularity. Fetal hemodynamics was unique in that sharp fall in arterial pulse pressure (APP) which was rapidly restored within 48h post-wounding. In adults, APP transiently increased post-wounding before returning to the pre-wounding levels by d10 post-wounding. The pattern of change in the elasticity of wound-edge tissue of diabetics was strikingly different. Severe strain acquired during the early inflammatory phase persisted with a slower recovery of elasticity compared to that of the non-diabetic group. Wound bed of adult diabetic mice (db/db) showed persistent hypercellularity compared to littermate controls (db/+) indicative of prolonged inflammation. Normal skin strain of db/+ and db/db were asynchronous. In db/db, severe strain acquired during the early inflammatory phase persisted with a slower recovery of elasticity compared to that of non-diabetics. This study showcases a versatile clinically relevant imaging platform suitable for real-time analyses of functional wound healing.
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Affiliation(s)
- Surya C. Gnyawali
- Department of Surgery, Davis Heart and Lung Research Institute, Center for Regenerative Medicine & Cell-Based Therapies, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
| | - Mithun Sinha
- Department of Surgery, Davis Heart and Lung Research Institute, Center for Regenerative Medicine & Cell-Based Therapies, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
- Department of Surgery, IUH Comprehensive Wound Center, Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Mohamed S. El Masry
- Department of Surgery, Davis Heart and Lung Research Institute, Center for Regenerative Medicine & Cell-Based Therapies, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
- Department of Surgery, IUH Comprehensive Wound Center, Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Department of Plastic and Reconstructive Surgery, Zagazig University, Zagazig, Egypt
| | - Brian Wulff
- Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
| | - Subhadip Ghatak
- Department of Surgery, Davis Heart and Lung Research Institute, Center for Regenerative Medicine & Cell-Based Therapies, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
- Department of Surgery, IUH Comprehensive Wound Center, Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Fidel Soto-Gonzalez
- Department of Surgery, Davis Heart and Lung Research Institute, Center for Regenerative Medicine & Cell-Based Therapies, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
| | - Traci A. Wilgus
- Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
| | - Sashwati Roy
- Department of Surgery, Davis Heart and Lung Research Institute, Center for Regenerative Medicine & Cell-Based Therapies, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
- Department of Surgery, IUH Comprehensive Wound Center, Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Chandan K. Sen
- Department of Surgery, Davis Heart and Lung Research Institute, Center for Regenerative Medicine & Cell-Based Therapies, The Ohio State University Wexner Medical Center, Columbus, OH, United States of America
- Department of Surgery, IUH Comprehensive Wound Center, Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, United States of America
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14
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Lin CY. Ramp-Creep Ultrasound Viscoelastography for Measuring Viscoelastic Parameters of Materials. MATERIALS 2020; 13:ma13163593. [PMID: 32823881 PMCID: PMC7475984 DOI: 10.3390/ma13163593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/07/2020] [Accepted: 08/12/2020] [Indexed: 12/21/2022]
Abstract
Several ultrasound-based methods have been developed to evaluate the viscoelastic properties of materials. The purpose of this study is to introduce a novel viscoelastography method based on ultrasound acoustic radiation force for measuring the parameters relevant to the viscoelastic properties of materials, named ramp-creep ultrasound viscoelastography (RC viscoelastography). RC viscoelastography uses two different ultrasound excitation modes to cause ramp and creep strain responses in the material. By combining and analyzing the information obtained from these two modes of excitation, the viscoelastic parameters of the material can be quantitatively evaluated. Finite element computer simulation demonstrated that RC viscoelastography can accurately evaluate the viscoelastic parameters of the material, including the relaxation and creep time constants as well as the ratio of viscous fluids to solids in the material, except for the region near the top surface of the material. The novelty of RC viscoelastography is that there is no need to know the magnitude of acoustic radiation force and induced stress in the material in order to evaluate the viscoelastic parameters. In the future, experiments are necessary to test the performance of RC viscoelastography in real biomaterials and biological tissues.
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Affiliation(s)
- Che-Yu Lin
- Institute of Applied Mechanics, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
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15
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Norris EG, Dalecki D, Hocking DC. Using Acoustic Fields to Fabricate ECM-Based Biomaterials for Regenerative Medicine Applications. RECENT PROGRESS IN MATERIALS 2020; 2:1-24. [PMID: 33604591 PMCID: PMC7889011 DOI: 10.21926/rpm.2003018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ultrasound is emerging as a promising tool for both characterizing and fabricating engineered biomaterials. Ultrasound-based technologies offer a diverse toolbox with outstanding capacity for optimization and customization within a variety of therapeutic contexts, including improved extracellular matrix-based materials for regenerative medicine applications. Non-invasive ultrasound fabrication tools include the use of thermal and mechanical effects of acoustic waves to modify the structure and function of extracellular matrix scaffolds both directly, and indirectly via biochemical and cellular mediators. Materials derived from components of native extracellular matrix are an essential component of engineered biomaterials designed to stimulate cell and tissue functions and repair or replace injured tissues. Thus, continued investigations into biological and acoustic mechanisms by which ultrasound can be used to manipulate extracellular matrix components within three-dimensional hydrogels hold much potential to enable the production of improved biomaterials for clinical and research applications.
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Affiliation(s)
- Emma G Norris
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - Diane Dalecki
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA
| | - Denise C Hocking
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA
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16
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Zareei A, Jiang H, Chittiboyina S, Zhou J, Marin BP, Lelièvre SA, Rahimi R. A lab-on-chip ultrasonic platform for real-time and nondestructive assessment of extracellular matrix stiffness. LAB ON A CHIP 2020; 20:778-788. [PMID: 31951245 DOI: 10.1039/c9lc00926d] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Extracellular matrix (ECM) mechanical stiffness and its dynamic change is one of the main cues that directly affects the differentiation and proliferation of normal cells as well as the progression of disease processes such as fibrosis and cancer. Recent advancements in biomaterials have enabled a wide range of polymer matrices that could mimic the ECM of different tissues for a wide range of in vitro basic research and drug discovery. However, most of the technologies utilized to quantify the stiffness of such ECM are either destructive or expensive, and therefore are unsuitable for the in situ, long-term monitoring of variations in ECM stiffness for on-chip cell culture applications. This work demonstrates a novel noninvasive on-chip platform for characterization of ECM stiffness in vitro, by monitoring ultrasonic wave attenuation through the targeted material. The device is composed of a pair of millimeter scale ultrasonic transmitter and receiver transducers with the test medium placed in between them. The transmitter generates an ultrasonic wave that propagates through the material, triggers the piezoelectric receiver and generates a corresponding electrical signal. The characterization reveals a linear (r2 = 0.86) decrease in the output voltage of the piezoelectric receiver with an average sensitivity of -15.86 μV kPa-1 by increasing the stiffnesses of hydrogels (from 4.3 kPa to 308 kPa made with various dry-weight concentrations of agarose and gelatin). The ultrasonic stiffness sensing is also demonstrated to successfully monitor dynamic changes in a simulated in vitro tissue by gradually changing the polymerization density of an agarose gel, as a proof-of-concept towards future use for 3D cell culture and drug screening. In situ long-term ultrasonic signal stability and thermal assessment of the device demonstrates its high robust performance even after two days of continuous operation, with negligible (<0.5 °C) heating of the hydrogel in contact with the piezoelectric transducers. In vitro biocompatibility assessment of the device with mammary fibroblasts further assures that the materials used in the platform did not produce a toxic response and cells remained viable under the applied ultrasound signals in the device.
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Affiliation(s)
- Amin Zareei
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA
| | - Hongjie Jiang
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA and School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Shirisha Chittiboyina
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA and Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Jiawei Zhou
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA and School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Beatriz Plaza Marin
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Sophie A Lelièvre
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA and Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA and Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Rahim Rahimi
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA. and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA
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17
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Guenther E, Klein N, Mikus P, Botea F, Pautov M, Lugnani F, Macchioro M, Popescu I, Stehling MK, Rubinsky B. Toward a clinical real time tissue ablation technology: combining electroporation and electrolysis (E2). PeerJ 2020; 8:e7985. [PMID: 31998549 PMCID: PMC6977482 DOI: 10.7717/peerj.7985] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 10/03/2019] [Indexed: 01/05/2023] Open
Abstract
Background Percutaneous image-guided tissue ablation (IGA) plays a growing role in the clinical management of solid malignancies. Electroporation is used for IGA in several modalities: irreversible electroporation (IRE), and reversible electroporation with chemotoxic drugs, called electrochemotherapy (ECT). It was shown that the combination of electrolysis and electroporation—E2—affords tissue ablation with greater efficiency, that is, lower voltages, lower energy and shorter procedure times than IRE and without the need for chemotoxic additives as in ECT. Methods A new E2 waveform was designed that delivers optimal doses of electroporation and electrolysis in a single waveform. A series of experiments were performed in the liver of pigs to evaluate E2 in the context of clinical applications. The goal was to find initial parameter boundaries in terms of electrical field, pulse duration and charge as well as tissue behavior to enable real time tissue ablation of clinically relevant volumes. Results Histological results show that a single several hundred millisecond long E2 waveform can ablate large volume of tissue at relatively low voltages while preserving the integrity of large blood vessels and lumen structures in the ablation zone without the use of chemotoxic drugs or paralyzing drugs during anesthesia. This could translate clinically into much shorter treatment times and ease of use compared to other techniques that are currently applied.
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Affiliation(s)
- Enric Guenther
- Biophysics, Inter Science GmbH, Gisikon, Lucerne, Switzerland.,Department of Bioengineering and Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA, USA.,Institut fur Bildgebende Diagnostik, Offenbach, Germany
| | - Nina Klein
- Biophysics, Inter Science GmbH, Gisikon, Lucerne, Switzerland.,Institut fur Bildgebende Diagnostik, Offenbach, Germany.,Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Paul Mikus
- Biophysics, Inter Science GmbH, Gisikon, Lucerne, Switzerland
| | - Florin Botea
- Center of General Surgery and Liver Transplantation, Fundeni Clinical Institute, Bucharest, Romania.,Center of Translational Medicine, Fundeni Clinical Institute, Bucharest, Romania
| | - Mihail Pautov
- Center of General Surgery and Liver Transplantation, Fundeni Clinical Institute, Bucharest, Romania.,Center of Translational Medicine, Fundeni Clinical Institute, Bucharest, Romania
| | | | | | - Irinel Popescu
- Center of General Surgery and Liver Transplantation, Fundeni Clinical Institute, Bucharest, Romania.,Center of Translational Medicine, Fundeni Clinical Institute, Bucharest, Romania
| | - Michael K Stehling
- Biophysics, Inter Science GmbH, Gisikon, Lucerne, Switzerland.,Department of Bioengineering and Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA, USA.,Institut fur Bildgebende Diagnostik, Offenbach, Germany
| | - Boris Rubinsky
- Biophysics, Inter Science GmbH, Gisikon, Lucerne, Switzerland.,Department of Bioengineering and Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA, USA
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18
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Contrast enhanced computed tomography for real-time quantification of glycosaminoglycans in cartilage tissue engineered constructs. Acta Biomater 2019; 100:202-212. [PMID: 31580960 DOI: 10.1016/j.actbio.2019.09.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/06/2019] [Accepted: 09/11/2019] [Indexed: 12/14/2022]
Abstract
Tissue engineering and regenerative medicine are two therapeutic strategies to treat, and to potentially cure, diseases affecting cartilaginous tissues, such as osteoarthritis and cartilage defects. Insights into the processes occurring during regeneration are essential to steer and inform development of the envisaged regenerative strategy, however tools are needed for longitudinal and quantitative monitoring of cartilage matrix components. In this study, we introduce a contrast-enhanced computed tomography (CECT)-based method using a cationic iodinated contrast agent (CA4+) for longitudinal quantification of glycosaminoglycans (GAG) in cartilage-engineered constructs. CA4+ concentration and scanning protocols were first optimized to ensure no cytotoxicity and a facile procedure with minimal radiation dose. Chondrocyte and mesenchymal stem cell pellets, containing different GAG content were generated and exposed to CA4+. The CA4+ content in the pellets, as determined by micro computed tomography, was plotted against GAG content, as measured by 1,9-dimethylmethylene blue analysis, and showed a high linear correlation. The established equation was used for longitudinal measurements of GAG content over 28 days of pellet culture. Importantly, this method did not adversely affect cell viability or chondrogenesis. Additionally, the CA4+ distribution accurately matched safranin-O staining on histological sections. Hence, we show proof-of-concept for the application of CECT, utilizing a positively charged contrast agent, for longitudinal and quantitative imaging of GAG distribution in cartilage tissue-engineered constructs. STATEMENT OF SIGNIFICANCE: Tissue engineering and regenerative medicine are promising therapeutic strategies for different joint pathologies such as cartilage defects or osteoarthritis. Currently, in vitro assessment on the quality and composition of the engineered cartilage mainly relies on destructive methods. Therefore, there is a need for the development of techniques that allow for longitudinal and quantitative imaging and monitoring of cartilage-engineered constructs. This work harnesses the electrostatic interactions between the negatively-charged glycosaminoglycans (GAGs) and a positively-charged contrast agent for longitudinal and non-destructive quantification of GAGs, providing valuable insight on GAG development and distribution in cartilage engineered constructs. Such technique can advance the development of regenerative strategies, not only by allowing continuous monitoring but also by serving as a pre-implantation screening tool.
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19
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Gil CJ, Tomov ML, Theus AS, Cetnar A, Mahmoudi M, Serpooshan V. In Vivo Tracking of Tissue Engineered Constructs. MICROMACHINES 2019; 10:E474. [PMID: 31315207 PMCID: PMC6680880 DOI: 10.3390/mi10070474] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/10/2019] [Accepted: 07/13/2019] [Indexed: 02/06/2023]
Abstract
To date, the fields of biomaterials science and tissue engineering have shown great promise in creating bioartificial tissues and organs for use in a variety of regenerative medicine applications. With the emergence of new technologies such as additive biomanufacturing and 3D bioprinting, increasingly complex tissue constructs are being fabricated to fulfill the desired patient-specific requirements. Fundamental to the further advancement of this field is the design and development of imaging modalities that can enable visualization of the bioengineered constructs following implantation, at adequate spatial and temporal resolution and high penetration depths. These in vivo tracking techniques should introduce minimum toxicity, disruption, and destruction to treated tissues, while generating clinically relevant signal-to-noise ratios. This article reviews the imaging techniques that are currently being adopted in both research and clinical studies to track tissue engineering scaffolds in vivo, with special attention to 3D bioprinted tissue constructs.
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Affiliation(s)
- Carmen J Gil
- Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, GA 30322, USA
| | - Martin L Tomov
- Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, GA 30322, USA
| | - Andrea S Theus
- Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, GA 30322, USA
| | - Alexander Cetnar
- Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, GA 30322, USA
| | - Morteza Mahmoudi
- Precision Health Program, Michigan State University, East Lansing, MI 48824, USA
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Vahid Serpooshan
- Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology, Atlanta, GA 30322, USA.
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30309, USA.
- Children's Healthcare of Atlanta, Atlanta, GA 30322, USA.
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20
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Byra M, Wan L, Wong JH, Du J, Shah SB, Andre MP, Chang EY. Quantitative Ultrasound and B-Mode Image Texture Features Correlate with Collagen and Myelin Content in Human Ulnar Nerve Fascicles. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1830-1840. [PMID: 30987909 DOI: 10.1016/j.ultrasmedbio.2019.02.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/16/2019] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
We investigate the usefulness of quantitative ultrasound and B-mode texture features for characterization of ulnar nerve fascicles. Ultrasound data were acquired from cadaveric specimens using a nominal 30-MHz probe. Next, the nerves were extracted to prepare histology sections. Eighty-five fascicles were matched between the B-mode images and the histology sections. For each fascicle image, we selected an intra-fascicular region of interest. We used histology sections to determine features related to the concentration of collagen and myelin and ultrasound data to calculate the backscatter coefficient (-24.89 ± 8.31 dB), attenuation coefficient (0.92 ± 0.04 db/cm-MHz), Nakagami parameter (1.01 ± 0.18) and entropy (6.92 ± 0.83), as well as B-mode texture features obtained via the gray-level co-occurrence matrix algorithm. Significant Spearman rank correlations between the combined collagen and myelin concentrations were obtained for the backscatter coefficient (R = -0.68), entropy (R = -0.51) and several texture features. Our study indicates that quantitative ultrasound may potentially provide information on structural components of nerve fascicles.
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Affiliation(s)
- Michal Byra
- Research Service, VA San Diego Healthcare System, San Diego, California, USA; Department of Radiology, University of California, San Diego, California, USA; Department of Ultrasound, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland.
| | - Lidi Wan
- Research Service, VA San Diego Healthcare System, San Diego, California, USA; Department of Radiology, University of California, San Diego, California, USA
| | - Jonathan H Wong
- Research Service, VA San Diego Healthcare System, San Diego, California, USA; Department of Radiology, University of California, San Diego, California, USA
| | - Jiang Du
- Research Service, VA San Diego Healthcare System, San Diego, California, USA; Department of Radiology, University of California, San Diego, California, USA
| | - Sameer B Shah
- Research Service, VA San Diego Healthcare System, San Diego, California, USA; Departments of Orthopedic Surgery and Bioengineering, University of California, San Diego, California, USA
| | - Michael P Andre
- Research Service, VA San Diego Healthcare System, San Diego, California, USA; Department of Radiology, University of California, San Diego, California, USA
| | - Eric Y Chang
- Research Service, VA San Diego Healthcare System, San Diego, California, USA; Department of Radiology, University of California, San Diego, California, USA
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21
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Ruland A, Gilmore KJ, Daikuara LY, Fay CD, Yue Z, Wallace GG. Quantitative ultrasound imaging of cell-laden hydrogels and printed constructs. Acta Biomater 2019; 91:173-185. [PMID: 31055120 DOI: 10.1016/j.actbio.2019.04.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/02/2019] [Accepted: 04/25/2019] [Indexed: 12/17/2022]
Abstract
In the present work we have revisited the application of quantitative ultrasound imaging (QUI) to cellular hydrogels, by using the reference phantom method (RPM) in combination with a local attenuation compensation algorithm. The investigated biological samples consisted of cell-laden collagen hydrogels with PC12 neural cells. These cell-laden hydrogels were used to calibrate the integrated backscattering coefficient (IBC) as a function of cell density, which was then used to generate parametric images of local cell density. The image resolution used for QUI and its impact on the relative IBC error was also investigated. Another important contribution of our work was the monitoring of PC12 cell proliferation. The cell number estimates obtained via the calibrated IBC compared well with data obtained using a conventional quantitative method, the MTS assay. Evaluation of spectral changes as a function of culture time also provided additional information on the cell cluster size, which was found to be in close agreement with that observed by microscopy. Last but not least, we also applied QUI on a 3D printed cellular construct in order to illustrate its capabilities for the evaluation of bioprinted structures. STATEMENT OF SIGNIFICANCE: While there is intensive research in the areas of polymer science, biology, and 3D bio-printing, there exists a gap in available characterisation tools for the non-destructive inspection of biological constructs in the three-dimensional domain, on the macroscopic scale, and with fast data acquisition times. Quantitative ultrasound imaging is a suitable characterization technique for providing essential information on the development of tissue engineered constructs. These results provide a detailed and comprehensive guide on the capabilities and limitations of the technique.
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22
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Hong X, Annamalai RT, Kemerer TS, Deng CX, Stegemann JP. Multimode ultrasound viscoelastography for three-dimensional interrogation of microscale mechanical properties in heterogeneous biomaterials. Biomaterials 2018; 178:11-22. [PMID: 29902533 DOI: 10.1016/j.biomaterials.2018.05.057] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 05/02/2018] [Accepted: 05/31/2018] [Indexed: 02/07/2023]
Abstract
Both static and time-dependent mechanical factors can have a profound impact on cell and tissue function, but it is challenging to measure the mechanical properties of soft materials at the scale which cells sense. Multimode ultrasound viscoelastography (MUVE) uses focused ultrasound pulses to both generate and image deformations within soft hydrogels non-invasively, at sub-millimeter resolution, and in 3D. The deformation and strain over time data are used to extract quantitative parameters that describe both the elastic and viscoelastic properties of the material. MUVE was used in creep mode to characterize the viscoelastic properties of 3D agarose, collagen, and fibrin hydrogels. Quantitative comparisons were made by extracting characteristic viscoelastic parameters using Burger's lumped parameter constitutive model. Spatial resolution of the MUVE technique was found to be approximately 200 μm, while detection sensitivity, defined as the capability to differentiate between materials based on mechanical property differences, was approximately 0.2 kPa using agarose hydrogels. MUVE was superior to nanoindentation and shear rheometry in generating consistent microscale measurements of viscoelastic behavior in soft materials. These results demonstrate that MUVE is a rapid, quantitative, and accurate method to measure the viscoelastic mechanical properties of soft 3D hydrogels at the microscale, and is a promising technique to study the development of native and engineered tissues over time.
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Affiliation(s)
- Xiaowei Hong
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, MI, MI 48109, USA
| | - Ramkumar T Annamalai
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, MI, MI 48109, USA
| | - Tyler S Kemerer
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, MI, MI 48109, USA
| | - Cheri X Deng
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, MI, MI 48109, USA.
| | - Jan P Stegemann
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, MI, MI 48109, USA.
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23
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Shazeeb MS, Corazzini R, Konowicz PA, Fogle R, Bangari DS, Johnson J, Ying X, Dhal PK. Assessment of in vivo degradation profiles of hyaluronic acid hydrogels using temporal evolution of chemical exchange saturation transfer (CEST) MRI. Biomaterials 2018; 178:326-338. [PMID: 29861090 DOI: 10.1016/j.biomaterials.2018.05.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/19/2018] [Accepted: 05/22/2018] [Indexed: 12/22/2022]
Abstract
Hyaluronic acid (HA) hydrogels have found a wide range of applications in biomedicine: regenerative medicine to drug delivery applications. In vivo quantitative assessment of these hydrogels using magnetic resonance imaging (MRI) provides an effective, accurate, safe, and non-invasive translational approach to assess the biodegradability of HA hydrogels. Chemical exchange saturation transfer (CEST) is an MRI contrast enhancement technique that overcomes the concentration limitation of other techniques like magnetic resonance spectroscopy (MRS) by detecting metabolites at up to two orders of magnitude or higher. In this study, HA hydrogels were synthesized based on different crosslinking agents and assessed using CEST MRI to investigate the in vivo degradation profiles of these gels in a mouse subcutaneous injection model over a three-month period. Nature of crosslinking agents was found to influence their degradation profiles. Since CEST MRI provides a unique chemical signature to visualize HA hydrogels, our studies proved that this technique could be used as a guide in the hydrogel optimization process for drug delivery and regenerative medicine applications.
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Affiliation(s)
| | - Rubina Corazzini
- Diabetes Research, Sanofi Global R&D, 153 Second Avenue, Waltham, MA 02451, USA
| | - Paul A Konowicz
- Diabetes Research, Sanofi Global R&D, 153 Second Avenue, Waltham, MA 02451, USA
| | - Robert Fogle
- Bioimaging Research, Sanofi Global R&D, 49 New York Avenue, Framingham, MA 01701, USA
| | - Dinesh S Bangari
- Pathology Research, Sanofi Global R&D, 5 Mountain Road, Framingham, MA 01701, USA
| | - Jennifer Johnson
- Pathology Research, Sanofi Global R&D, 5 Mountain Road, Framingham, MA 01701, USA
| | - Xiaoyou Ying
- Bioimaging Research, Sanofi Global R&D, 49 New York Avenue, Framingham, MA 01701, USA.
| | - Pradeep K Dhal
- Diabetes Research, Sanofi Global R&D, 153 Second Avenue, Waltham, MA 02451, USA.
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Ranganathan K, Hong X, Cholok D, Habbouche J, Priest C, Breuler C, Chung M, Li J, Kaura A, Hsieh HHS, Butts J, Ucer S, Schwartz E, Buchman SR, Stegemann JP, Deng CX, Levi B. High-frequency spectral ultrasound imaging (SUSI) visualizes early post-traumatic heterotopic ossification (HO) in a mouse model. Bone 2018; 109:49-55. [PMID: 29412179 PMCID: PMC5955392 DOI: 10.1016/j.bone.2018.01.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 01/30/2018] [Accepted: 01/30/2018] [Indexed: 11/20/2022]
Abstract
PURPOSE Early treatment of heterotopic ossification (HO) is currently limited by delayed diagnosis due to limited visualization at early time points. In this study, we validate the use of spectral ultrasound imaging (SUSI) in an animal model to detect HO as early as one week after burn tenotomy. METHODS Concurrent SUSI, micro CT, and histology at 1, 2, 4, and 9weeks post-injury were used to follow the progression of HO after an Achilles tenotomy and 30% total body surface area burn (n=3-5 limbs per time point). To compare the use of SUSI in different types of injury models, mice (n=5 per group) underwent either burn/tenotomy or skin incision injury and were imaged using a 55MHz probe on VisualSonics VEVO 770 system at one week post injury to evaluate the ability of SUSI to distinguish between edema and HO. Average acoustic concentration (AAC) and average scatterer diameter (ASD) were calculated for each ultrasound image frame. Micro CT was used to calculate the total volume of HO. Histology was used to confirm bone formation. RESULTS Using SUSI, HO was visualized as early as 1week after injury. HO was visualized earliest by 4weeks after injury by micro CT. The average acoustic concentration of HO was 33% more than that of the control limb (n=5). Spectroscopic foci of HO present at 1week that persisted throughout all time points correlated with the HO present at 9weeks on micro CT imaging. CONCLUSION SUSI visualizes HO as early as one week after injury in an animal model. SUSI represents a new imaging modality with promise for early diagnosis of HO.
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Affiliation(s)
- Kavitha Ranganathan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Xiaowei Hong
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - David Cholok
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Joe Habbouche
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Caitlin Priest
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | | | - Michael Chung
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - John Li
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Arminder Kaura
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | | | - Jonathan Butts
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Serra Ucer
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Ean Schwartz
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Steven R Buchman
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Jan P Stegemann
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Cheri X Deng
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Benjamin Levi
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA.
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Xia T, Liu W, Yang L. A review of gradient stiffness hydrogels used in tissue engineering and regenerative medicine. J Biomed Mater Res A 2017; 105:1799-1812. [DOI: 10.1002/jbm.a.36034] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/30/2017] [Accepted: 02/08/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Tingting Xia
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College; Chongqing University; Chongqing 400044 China
| | - Wanqian Liu
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College; Chongqing University; Chongqing 400044 China
| | - Li Yang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College; Chongqing University; Chongqing 400044 China
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Koo H, Yamada KM. Dynamic cell-matrix interactions modulate microbial biofilm and tissue 3D microenvironments. Curr Opin Cell Biol 2016; 42:102-112. [PMID: 27257751 PMCID: PMC5064909 DOI: 10.1016/j.ceb.2016.05.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 05/07/2016] [Accepted: 05/10/2016] [Indexed: 01/22/2023]
Abstract
Microbial biofilms and most eukaryotic tissues consist of cells embedded in a three-dimensional extracellular matrix. This matrix serves as a scaffold for cell adhesion and a dynamic milieu that provides varying chemical and physical signals to the cells. Besides a vast array of specific molecular components, an extracellular matrix can provide locally heterogeneous microenvironments differing in porosity/diffusion, stiffness, pH, oxygen and metabolites or nutrient levels. Mechanisms of matrix formation, mechanosensing, matrix remodeling, and modulation of cell-cell or cell-matrix interactions and dispersal are being revealed. This perspective article aims to identify such concepts from the fields of biofilm or eukaryotic matrix biology relevant to the other field to help stimulate new questions, approaches, and insights.
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Affiliation(s)
- Hyun Koo
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, PA 19104, USA.
| | - Kenneth M Yamada
- Laboratory of Cell and Developmental Biology, Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
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Microscale characterization of the viscoelastic properties of hydrogel biomaterials using dual-mode ultrasound elastography. Biomaterials 2016; 88:12-24. [PMID: 26928595 DOI: 10.1016/j.biomaterials.2016.02.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/11/2016] [Accepted: 02/16/2016] [Indexed: 01/21/2023]
Abstract
Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger's viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials.
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