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Long T, Vemaganti K, Hawes JE, Lin CY. An experimental study of the heterogeneity and anisotropy of porcine meniscal ultimate tensile strength. J Mech Behav Biomed Mater 2024; 157:106649. [PMID: 39024732 DOI: 10.1016/j.jmbbm.2024.106649] [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] [Received: 03/25/2024] [Revised: 06/19/2024] [Accepted: 07/01/2024] [Indexed: 07/20/2024]
Abstract
Characterizing the ultimate tensile strength (UTS) of the meniscus is critical in studying knee damage and pathology. This study aims to determine the UTS of the meniscus with an emphasis on its heterogeneity and anisotropy. We performed tensile tests to failure on the menisci of six month old Yorkshire pigs at a low strain rate. Specimens from the anterior, middle and posterior regions of the meniscus were tested in the radial and circumferential directions. Then the UTS was obtained for each specimen and the data were analyzed statistically, leading to a comprehensive view of the variations in porcine meniscal strength. The middle region has the highest average strength in the circumferential (43.3 ± 4.7 MPa) and radial (12.6 ± 2.2 MPa) directions. This is followed by the anterior and posterior regions, which present similar average values (about 34.0MPa) in circumferential direction. The average strength of each region in the radial direction is approximately one-fourth to one-third of the value in the circumferential direction. This study is novel as it is the first work to focus on the experimental methods to investigate the heterogeneity and anisotropy only for porcine meniscus.
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Affiliation(s)
- Teng Long
- Department of Mechanical and Materials Engineering, College of Engineering and Applied Science, University of Cincinnati, 2901 Woodside Drive, Cincinnati, 45221-0072, OH, USA
| | - Kumar Vemaganti
- Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, 87123, NM, USA
| | - James Edward Hawes
- Department of Biomedical Engineering, College of Engineering and Applied Science, University of Cincinnati, 2901 Woodside Drive, Cincinnati, 45221-0012, OH, USA
| | - Chia-Ying Lin
- Department of Orthopaedic Surgery, College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, 45267-0212, OH, USA.
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2
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Valente R, Mourato A, Xavier J, Sousa P, Domingues T, Tavares P, Avril S, Tomás A, Fragata J. Experimental Protocols to Test Aortic Soft Tissues: A Systematic Review. Bioengineering (Basel) 2024; 11:745. [PMID: 39199703 PMCID: PMC11351783 DOI: 10.3390/bioengineering11080745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Accepted: 07/18/2024] [Indexed: 09/01/2024] Open
Abstract
Experimental protocols are fundamental for quantifying the mechanical behaviour of soft tissue. These data are crucial for advancing the understanding of soft tissue mechanics, developing and calibrating constitutive models, and informing the development of more accurate and predictive computational simulations and artificial intelligence tools. This paper offers a comprehensive review of experimental tests conducted on soft aortic tissues, employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, based on the Scopus, Web of Science, IEEE, Google Scholar and PubMed databases. This study includes a detailed overview of the test method protocols, providing insights into practical methodologies, specimen preparation and full-field measurements. The review also briefly discusses the post-processing methods applied to extract material parameters from experimental data. In particular, the results are analysed and discussed providing representative domains of stress-strain curves for both uniaxial and biaxial tests on human aortic tissue.
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Affiliation(s)
- Rodrigo Valente
- UNIDEMI, Department of Mechanical and Industrial Engineering, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (R.V.); (A.M.)
| | - André Mourato
- UNIDEMI, Department of Mechanical and Industrial Engineering, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (R.V.); (A.M.)
| | - José Xavier
- UNIDEMI, Department of Mechanical and Industrial Engineering, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (R.V.); (A.M.)
- Intelligent Systems Associate Laboratory, LASI, 4800-058 Guimarães, Portugal
| | - Pedro Sousa
- INEGI, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (P.S.); (P.T.)
| | - Tiago Domingues
- INEGI, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (P.S.); (P.T.)
| | - Paulo Tavares
- INEGI, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (P.S.); (P.T.)
| | - Stéphane Avril
- Mines Saint-Etienne, University of Lyon, Inserm, Sainbiose U1059, Campus Santé Innovation, 10, rue de la Marandière, 42270 Saint-Priest-en-Jarez, France;
| | - António Tomás
- Department of Cardiothoracic Surgery, Santa Marta Hospital, Rua de Santa Marta, 1169-024 Lisboa, Portugal; (A.T.); (J.F.)
| | - José Fragata
- Department of Cardiothoracic Surgery, Santa Marta Hospital, Rua de Santa Marta, 1169-024 Lisboa, Portugal; (A.T.); (J.F.)
- Department of Surgery and Human Morphology, NOVA Medical School, Universidade NOVA de Lisboa, Campo Mártires da Pátria, 1169-056 Lisboa, Portugal
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Brecs I, Skuja S, Kasyanov V, Groma V, Kalejs M, Svirskis S, Ozolanta I, Stradins P. From Biomechanical Properties to Morphological Variations: Exploring the Interplay between Aortic Valve Cuspidity and Ascending Aortic Aneurysm. J Clin Med 2024; 13:4225. [PMID: 39064264 PMCID: PMC11277922 DOI: 10.3390/jcm13144225] [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: 06/12/2024] [Revised: 07/11/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Background: This research explores the biomechanical and structural characteristics of ascending thoracic aortic aneurysms (ATAAs), focusing on the differences between bicuspid aortic valve aneurysms (BAV-As) and tricuspid aortic valve aneurysms (TAV-As) with non-dilated aortas to identify specific traits of ATAAs. Methods: Clinical characteristics, laboratory indices, and imaging data from 26 adult patients operated on for aneurysms (BAV-A: n = 12; TAV-A: n = 14) and 13 controls were analyzed. Biomechanical parameters (maximal aortic diameter, strain, and stress) and structural analyses (collagen fiber organization, density, fragmentation, adipocyte deposits, and immune cell infiltration) were assessed. Results: Significant differences in biomechanical parameters were observed. Median maximal strain was 40.0% (control), 63.4% (BAV-A), and 45.3% (TAV-A); median maximal stress was 0.59 MPa (control), 0.78 MPa (BAV-A), and 0.48 MPa (TAV-A). BAV-A showed higher tangential modulus and smaller diameter, with substantial collagen fragmentation (p < 0.001 vs. TAV and controls). TAV-A exhibited increased collagen density (p = 0.025), thickening between media and adventitia layers, and disorganized fibers (p = 0.036). BAV-A patients had elevated adipocyte deposits and immune cell infiltration. Conclusions: This study highlights distinct pathological profiles associated with different valve anatomies. BAV-A is characterized by smaller diameters, higher biomechanical stress, and significant collagen deterioration, underscoring the necessity for tailored clinical strategies for effective management of thoracic aortic aneurysm.
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Affiliation(s)
- Ivars Brecs
- Faculty of Medicine, Riga Stradins University, 16 Dzirciema Street, LV-1007 Riga, Latvia; (V.K.); (M.K.); (I.O.); (P.S.)
- Centre of Cardiac Surgery, Pauls Stradins Clinical University Hospital, 13 Pilsonu Street, LV-1002 Riga, Latvia
| | - Sandra Skuja
- Joint Laboratory of Electron Microscopy, Riga Stradins University, 9 Kronvalda Boulevard, LV-1010 Riga, Latvia; (S.S.); (V.G.)
| | - Vladimir Kasyanov
- Faculty of Medicine, Riga Stradins University, 16 Dzirciema Street, LV-1007 Riga, Latvia; (V.K.); (M.K.); (I.O.); (P.S.)
- Laboratory of Biomechanics, Riga Stradins University, 5a Ratsupites Street, LV-1067 Riga, Latvia
| | - Valerija Groma
- Joint Laboratory of Electron Microscopy, Riga Stradins University, 9 Kronvalda Boulevard, LV-1010 Riga, Latvia; (S.S.); (V.G.)
| | - Martins Kalejs
- Faculty of Medicine, Riga Stradins University, 16 Dzirciema Street, LV-1007 Riga, Latvia; (V.K.); (M.K.); (I.O.); (P.S.)
- Centre of Cardiac Surgery, Pauls Stradins Clinical University Hospital, 13 Pilsonu Street, LV-1002 Riga, Latvia
| | - Simons Svirskis
- Institute of Microbiology and Virology, Riga Stradins University, 5 Ratsupites Street, LV-1067 Riga, Latvia;
| | - Iveta Ozolanta
- Faculty of Medicine, Riga Stradins University, 16 Dzirciema Street, LV-1007 Riga, Latvia; (V.K.); (M.K.); (I.O.); (P.S.)
- Laboratory of Biomechanics, Riga Stradins University, 5a Ratsupites Street, LV-1067 Riga, Latvia
| | - Peteris Stradins
- Faculty of Medicine, Riga Stradins University, 16 Dzirciema Street, LV-1007 Riga, Latvia; (V.K.); (M.K.); (I.O.); (P.S.)
- Centre of Cardiac Surgery, Pauls Stradins Clinical University Hospital, 13 Pilsonu Street, LV-1002 Riga, Latvia
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van der Laan KWF, Reesink KD, Lambrichts S, Bitsch NJJE, van der Taelen L, Foulquier S, Delhaas T, Spronck B, Giudici A. Effect of rapid cooling, frozen storage, and thawing on the passive viscoelastic properties and structure of the rat aorta. J Biomech 2024; 171:112190. [PMID: 38897049 DOI: 10.1016/j.jbiomech.2024.112190] [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] [Received: 11/21/2023] [Revised: 05/21/2024] [Accepted: 06/07/2024] [Indexed: 06/21/2024]
Abstract
Biological tissues decay over time after harvesting, which alters their biomechanical properties. This poses logistical challenges for studies investigating passive arterial biomechanics as tissues need to be characterized shortly after excision. Freezing and cryopreservation methods can help alleviate the need for biomechanical testing of fresh tissue in human ex vivo studies. However, these methods tend to eliminate or reduce arterial cell functionality and affect passive biomechanics. Furthermore, their impact on dynamic arterial biomechanics remains unknown despite arterial viscoelastic properties being an integral component contributing to arterial stiffness under in vivo loading conditions. The present study aims to investigate the impact of rapid cooling and subsequent storage at -80 °C on the passive viscoelastic properties of arterial tissue and aid in ascertaining whether this is a suitable method to delay tissue analysis for studies investigating passive arterial biomechanics. Control and frozen abdominal rat aorta segments were quasi-statically and dynamically tested using a biaxial testing set-up. The results were modeled using a constituent-based quasi-linear viscoelastic modeling framework, yielding directional stiffness parameters, individual constituent biomechanical contributions, and a quantification of viscoelastic stiffening under dynamic pressurization conditions. Frozen samples displayed significantly decreased wall thickness, viscoelastic dissipation, viscoelastic stiffening, and significantly decreased circumferential deformation with changes in luminal pressure. Furthermore, frozen samples displayed significantly increased circumferential stiffness, pulse wave velocity, and collagen load bearing. Consequently, these changes should be considered when utilizing this tissue preservation method to delay biomechanical characterization of rat aortic tissue.
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Affiliation(s)
- Koen W F van der Laan
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Koen D Reesink
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Sara Lambrichts
- Department of Pharmacology & Toxicology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; MHENS School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | | | - Laura van der Taelen
- Department of Pharmacology & Toxicology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Sébastien Foulquier
- Department of Pharmacology & Toxicology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; MHENS School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Tammo Delhaas
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Bart Spronck
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Alessandro Giudici
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; GROW School for Oncology and Reproduction, Maastricht University, Maastricht, The Netherlands.
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5
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Kostelnik CJ, Crouse KJ, Goldsmith JD, Eberth JF. Impact of cryopreservation on elastomuscular artery mechanics. J Mech Behav Biomed Mater 2024; 154:106503. [PMID: 38522154 DOI: 10.1016/j.jmbbm.2024.106503] [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] [Received: 01/19/2024] [Revised: 03/04/2024] [Accepted: 03/08/2024] [Indexed: 03/26/2024]
Abstract
Low temperatures slow or halt undesired biological and chemical processes, protecting cells, tissues, and organs during storage. Cryopreservation techniques, including controlled media exchange and regulated freezing conditions, aim to mitigate the physical consequences of freezing. Dimethyl sulfoxide (DMSO), for example, is a penetrating cryoprotecting agent (CPA) that minimizes ice crystal growth by replacing intracellular water, while polyvinyl alcohol (PVA) is a nonpenetrating CPA that prevents recrystallization during thawing. Since proteins and ground substance dominate the passive properties of soft biological tissues, we studied how different freezing rates, storage temperatures, storage durations, and the presence of cryoprotecting agents (5% [v/v] DMSO + 1 mg/mL PVA) impact the histomechanical properties of the internal thoracic artery (ITA), a clinically relevant blood vessel with both elastic and muscular characteristics. Remarkably, biaxial mechanical analyses failed to reveal significant differences among the ten groups tested, suggesting that mechanical properties are virtually independent of the cryopreservation technique. Scanning electron microscopy revealed minor CPA-independent delamination in rapidly frozen samples, while cryoprotected ITAs had better post-thaw viability than their unprotected counterparts using methyl thiazole-tetrazolium (MTT) metabolic assays, especially when frozen at a controlled rate. These results can be used to inform ongoing and future studies in vascular engineering, physiology, and mechanics.
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Affiliation(s)
- Colton J Kostelnik
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, TX, USA; Biomedical Engineering Program, University of South Carolina, Columbia, SC, USA
| | - Kiersten J Crouse
- Mechanical Engineering Department, University of South Carolina, Columbia, SC, USA
| | - Jackson D Goldsmith
- Mechanical Engineering Department, University of South Carolina, Columbia, SC, USA
| | - John F Eberth
- Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA.
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6
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Spek RW, Hoogervorst LA, Brink RC, Schoones JW, van Deurzen DF, van den Bekerom MP. Ten technical aspects of baseplate fixation in reverse total shoulder arthroplasty for patients without glenoid bone loss: a systematic review. Clin Shoulder Elb 2024; 27:88-107. [PMID: 38147872 PMCID: PMC10938023 DOI: 10.5397/cise.2023.00493] [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: 06/17/2023] [Revised: 08/08/2023] [Accepted: 08/17/2023] [Indexed: 12/28/2023] Open
Abstract
The aim of this systematic review was to collect evidence on the following 10 technical aspects of glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA): screw insertion angles; screw orientation; screw quantity; screw length; screw type; baseplate tilt; baseplate position; baseplate version and rotation; baseplate design; and anatomical safe zones. Five literature libraries were searched for eligible clinical, cadaver, biomechanical, virtual planning, and finite element analysis studies. Studies including patients >16 years old in which at least one of the ten abovementioned technical aspects was assessed were suitable for analysis. We excluded studies of patients with: glenoid bone loss; bony increased offset-reversed shoulder arthroplasty; rTSA with bone grafts; and augmented baseplates. Quality assessment was performed for each included study. Sixty-two studies were included, of which 41 were experimental studies (13 cadaver, 10 virtual planning, 11 biomechanical, and 7 finite element studies) and 21 were clinical studies (12 retrospective cohorts and 9 case-control studies). Overall, the quality of included studies was moderate or high. The majority of studies agreed upon the use of a divergent screw fixation pattern, fixation with four screws (to reduce micromotions), and inferior positioning in neutral or anteversion. A general consensus was not reached on the other technical aspects. Most surgical aspects of baseplate fixation can be decided without affecting fixation strength. There is not a single strategy that provides the best outcome. Therefore, guidelines should cover multiple surgical options that can achieve adequate baseplate fixation.
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Affiliation(s)
- Reinier W.A. Spek
- Department of Orthopaedic Surgery, Flinders University and Flinders Medical Center, Adelaide, Australia
- Department of Orthopaedic Surgery, OLVG Amsterdam, Amsterdam, the Netherlands
- Department of Orthopaedic Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Lotje A. Hoogervorst
- Department of Orthopaedics, Leiden University Medical Center, Leiden, the Netherlands
- Department of Biomedical Data Sciences and Medical Decision Making, Leiden University Medical Center, Leiden, the Netherlands
| | - Rob C. Brink
- Department of Orthopaedic Surgery, OLVG Amsterdam, Amsterdam, the Netherlands
| | - Jan W. Schoones
- Walaeus Library, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Michel P.J. van den Bekerom
- Department of Orthopaedic Surgery, OLVG Amsterdam, Amsterdam, the Netherlands
- Shoulder and Elbow Expertise Center, Amsterdam, the Netherlands
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
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7
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Lee CW, Lee C, Baek S, Akkoyun E, Ryu D. Investigating the influence of collagen cross-linking on mechanical properties of thoracic aortic tissue. Front Bioeng Biotechnol 2024; 12:1305128. [PMID: 38476969 PMCID: PMC10928930 DOI: 10.3389/fbioe.2024.1305128] [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: 09/30/2023] [Accepted: 02/07/2024] [Indexed: 03/14/2024] Open
Abstract
Vascular diseases, such as abdominal aortic aneurysms, are associated with tissue degeneration of the aortic wall, resulting in variations in mechanical properties, such as tissue ultimate stress and a high slope. Variations in the mechanical properties of tissues may be associated with an increase in the number of collagen cross-links. Understanding the effect of collagen cross-linking on tissue mechanical properties can significantly aid in predicting diseased aortic tissue rupture and improve the clarity of decisions regarding surgical procedures. Therefore, this study focused on increasing the density of the aortic tissue through cross-linking and investigating the mechanical properties of the thoracic aortic tissue in relation to density. Uniaxial tensile tests were conducted on the porcine thoracic aorta in four test regions (anterior, posterior, distal, and proximal), two loading directions (circumferential and longitudinal), and density increase rates (0%-12%). As a result, the PPC (Posterior/Proximal/Circumferential) group experienced a higher ultimate stress than the PDC (Posterior/Distal/Circumferential) group. However, this relationship reversed when the specimen density exceeded 3%. In addition, the ultimate stress of the ADC (Anterior/Distal/Circumferential) and PPC group was greater than that of the APC (Anterior/Proximal/Circumferential) group, while these findings were reversed when the specimen density exceeded 6% and 9%, respectively. Finally, the high slope of the PDL (Posterior/Distal/Longitudinal) group was lower than that of the ADL (Anterior/Distal/Longitudinal) group, but the high slope of the PDL group appeared larger due to the stabilization treatment. This highlights the potential impact of density variations on the mechanical properties of specific specimen groups.
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Affiliation(s)
- Chung Won Lee
- Department of Thoracic and Cardiovascular Surgery, School of Medicine, Pusan National University, Busan, Republic of Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
| | - Chiseung Lee
- Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
- Department of Convergence Medicine and Biomedical Engineering, School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Seungik Baek
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, United States
| | - Emrah Akkoyun
- TÜBITAK-ULAKBIM, Turkish Academic Network and Information Center, Ankara, Türkiye
| | - Dongman Ryu
- Medical Research Institute, Pusan National University, Busan, Republic of Korea
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Garcia M, Momenzadah K, Shariyate MJ, Kheir N, Khak M, Villarreal JB, Abbasian M, Flaherty AF, Hanna P, Ramappa A, Paschos NK, Nazarian A. Plastic and elastic biomechanical properties of anterior cruciate ligament autografts. BMC Musculoskelet Disord 2024; 25:157. [PMID: 38373917 PMCID: PMC10875842 DOI: 10.1186/s12891-024-07262-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 02/05/2024] [Indexed: 02/21/2024] Open
Abstract
BACKGROUND Anterior cruciate ligament (ACL) rupture is a common orthopedic injury, occurring in roughly 68.6 per 100,000 persons annually, with the primary treatment option being ACL reconstruction. However, debate remains about the appropriate graft type for restoring the native biomechanical properties of the knee. Furthermore, plastic graft elongation may promote increased knee laxity and instability without rupture. This study aims to investigate the plastic properties of common ACL-R graft options. METHODS Patellar tendon (PT), hamstring tendon (HT), and quadriceps tendon (QT) grafts were harvested from 11 cadaveric knees (6 male and 5 female) with a mean age of 71(range 55-81). All grafts were mechanically tested under uniaxial tension until failure to determine each graft's elastic and plastic biomechanical properties. RESULTS Mechanically, the QT graft was the weakest, exhibiting the lowest failure force and the lowest failure stress (QT < HT, p = 0.032). The PT was the stiffest of the grafts, having a significantly higher stiffness (PT > QT, p = 0.0002) and Young's modulus (PT > QT, p = 0.001; PT > HT, p = 0.041). The HT graft had the highest plastic elongation at 4.01 ± 1.32 mm (HT > PT, p = 0.002). The post-yield behavior of the HT tendon shows increased energy storage capabilities with the highest plastic energy storage (HT > QT, p = 0.012) and the highest toughness (HT > QT, p = 0.032). CONCLUSION Our study agrees with prior studies indicating that the failure load of all grafts is above the requirements for everyday activities. However, grafts may be susceptible to yielding before failure during daily activities. This may result in the eventual loss of functionality for the neo-ACL, resulting in increased knee laxity and instability.
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Affiliation(s)
- Mason Garcia
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
- Mechanical Engineering Department, Boston University, Boston, MA, USA
| | - Kaveh Momenzadah
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
- Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Mohammad Javad Shariyate
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
- Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Nadim Kheir
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
| | - Mohammad Khak
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
- Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Juan B Villarreal
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
- Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Mohammadreza Abbasian
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
| | - Alexandra F Flaherty
- Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Philip Hanna
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA
- Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Arun Ramappa
- Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Nikolaos K Paschos
- Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Ara Nazarian
- Musculoskeletal Translational Innovation Initiative, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, RN123, Boston, MA, 02115, USA.
- Mechanical Engineering Department, Boston University, Boston, MA, USA.
- Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
- Department of Orthopaedic Surgery, Yerevan State Medical University, Yerevan, Armenia.
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9
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Illi J, Ilic M, Stark AW, Amstutz C, Burger J, Zysset P, Haeberlin A, Gräni C. Mechanical testing and comparison of porcine tissue, silicones and 3D-printed materials for cardiovascular phantoms. Front Bioeng Biotechnol 2023; 11:1274673. [PMID: 38107617 PMCID: PMC10725245 DOI: 10.3389/fbioe.2023.1274673] [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: 08/11/2023] [Accepted: 11/20/2023] [Indexed: 12/19/2023] Open
Abstract
Background: Cardiovascular phantoms for patient education, pre-operative planning, surgical training, haemodynamic simulation, and device testing may help improve patient care. However, currently used materials may have different mechanical properties compared to biological tissue. Methods/Aim: The aim of this study was to investigate the mechanical properties of 3D-printing and silicone materials in comparison to biological cardiovascular tissues. Uniaxial cyclic tension testing was performed using dumbbell samples from porcine tissue (aorta, pulmonary artery, right and left ventricle). Flexible testing materials included 15 silicone (mixtures) and three 3D-printing materials. The modulus of elasticity was calculated for different deformation ranges. Results: The modulus of elasticity (0%-60%) for the aorta ranged from 0.16 to 0.18 N/mm2, for the pulmonary artery from 0.07 to 0.09 N/mm2, and for the right ventricle as well as the left ventricle short-axis from 0.1 to 0.16 N/mm2. For silicones the range of modulus of elasticity was 0.02-1.16 N/mm2, and for the 3D-printed materials from 0.85 to 1.02 N/mm2. The stress-strain curves of all tissues showed a non-linear behaviour in the cyclic tensile testing, with a distinct toe region, followed by exponential strain hardening behaviour towards the peak elongation. The vessel samples showed a more linear behaviour comparted to myocardial samples. The silicones and 3D printing materials exhibited near-linearity at higher strain ranges, with a decrease in stiffness following the initial deformation. All samples showed a deviation between the loading and unloading curves (hysteresis), and a reduction in peak force over the first few cycles (adaptation effect) at constant deformation. Conclusion: The modulus of elasticity of silicone mixtures is more in agreement to porcine cardiovascular tissues than 3D-printed materials. All synthetic materials showed an almost linear behaviour in the mechanical testing compared to the non-linear behaviour of the biological tissues, probably due to fibre recruitment mechanism in the latter.
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Affiliation(s)
- Joël Illi
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marc Ilic
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Anselm Walter Stark
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Cornelia Amstutz
- School of Biomedical and Precision Engineering, University of Bern, Bern, Switzerland
| | - Juergen Burger
- School of Biomedical and Precision Engineering, University of Bern, Bern, Switzerland
| | - Philippe Zysset
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - Andreas Haeberlin
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
- Translational Imaging Center, Sitem Center, University of Bern, Bern, Switzerland
| | - Christoph Gräni
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Translational Imaging Center, Sitem Center, University of Bern, Bern, Switzerland
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10
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Grosha J, Cho JH, Pasley S, Kilbride P, Zylberberg C, Rolle MW. Engineered Test Tissues: A Model for Quantifying the Effects of Cryopreservation Parameters. ACS Biomater Sci Eng 2023; 9:6198-6207. [PMID: 37802599 DOI: 10.1021/acsbiomaterials.3c00752] [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: 10/10/2023]
Abstract
Engineered tissues are showing promise as implants to repair or replace damaged tissues in vivo or as in vitro tools to discover new therapies. A major challenge of the tissue engineering field is the sample preservation and storage until their transport and desired use. To successfully cryopreserve tissue, its viability, structure, and function must be retained post-thaw. The outcome of cryopreservation is impacted by several parameters, including the cryopreserving agent (CPA) utilized, the cooling rate, and the storage temperature. Although a number of CPAs are commercially available for cell cryopreservation, there are few CPAs designed specifically for tissue cryostorage and recovery. In this study, we present a flexible, relatively high-throughput method that utilizes engineered tissue rings as test tissues for screening the commercially available CPAs and cryopreservation parameters. Engineered test tissues can be fabricated with low batch-to-batch variability and characteristic morphology due to their endogenous extracellular matrix, and they have mechanical properties and a ring format suitable for testing with standard methods. The tissues were grown for 7 days in standard 48-well plates and cryopreserved in standard cryovials. The method allowed for the quantification of metabolic recovery, tissue apoptosis/necrosis, morphology, and mechanical properties. In addition to establishing the method, we tested different CPA formulations, freezing rates, and freezing points. Our proposed method enables timely preliminary screening of CPA formulations and cryopreservation parameters that may improve the storage of engineered tissues.
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Affiliation(s)
- Jonian Grosha
- Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
| | - Jun-Hung Cho
- Akron Biotech, Boca Raton, Florida 33487, United States
| | | | | | | | - Marsha W Rolle
- Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
- The Roux Institute, Northeastern University, Portland, Maine 04101, United States
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11
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Recco DP, Kizilski SB, Marshall LE, Earley PD, Kneier NE, del Nido PJ, Hammer PE, Hoganson DM. Mechanical failure analysis of patch materials used in aortic arch reconstruction: implications for clinical practice. Eur J Cardiothorac Surg 2023; 64:ezad366. [PMID: 37897688 PMCID: PMC11005168 DOI: 10.1093/ejcts/ezad366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/17/2023] [Accepted: 10/27/2023] [Indexed: 10/30/2023] Open
Abstract
OBJECTIVES Thick-patch pulmonary homograft, autologous pericardium and CardioCel Neo are common patch materials for aortic arch reconstruction. Insufficient data exist on sutured patch strength and limits of use. We evaluated failure strength of these materials to develop a failure prediction model for clinical guidance. METHODS Patch failure strength was evaluated via sutured uniaxial and burst pressure testing. In sutured uniaxial testing, patches were sutured to aortic or Dacron tabs and pulled to failure. In burst pressure testing, patches were sewn into porcine aortas or Dacron grafts and pressurized to failure. Failure membrane tension was calculated. A prediction model of membrane tension versus vessel diameter was generated to guide clinical patch selection. RESULTS Combining sutured uniaxial and burst pressure test data, pulmonary homograft failure strength {0.61 [interquartile range (IQR): 0.44, 0.78] N/mm, n = 21} was less than half that of autologous pericardium [2.22 (IQR: 1.65, 2.78) N/mm, n = 15] and CardioCel Neo [1.31 (IQR: 1.20, 1.42) N/mm, n = 20]. Pulmonary homograft burst pressure [245 (IQR: 202, 343) mmHg, n = 7] was significantly lower than autologous pericardium [863 (IQR: 802, 919) mmHg, n = 6] and CardioCel Neo [766 (IQR: 721, 833) mmHg, n = 6]. Our model predicts failure limits for each patch material and outlines safety margins for combinations of aortic diameter and pressure. CONCLUSIONS Sutured failure strength of thick-patch pulmonary homograft was significantly lower than autologous pericardium and CardioCel Neo. Patient selection (predicted postoperative arch diameter and haemodynamics) and blood pressure management must be considered when choosing patch material for arch reconstruction. In older children and adolescents, autologous or bovine pericardium may be more suitable materials for aortic patch augmentation to minimize the risk of postoperative patch failure.
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Affiliation(s)
- Dominic P Recco
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Shannen B Kizilski
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Lauren E Marshall
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
| | - Patrick D Earley
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
| | - Nicholas E Kneier
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
| | - Pedro J del Nido
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Peter E Hammer
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - David M Hoganson
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
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12
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Mikhail J, Funabashi M, Sobczak S, Descarreaux M, Pagé I. Investigation of the factors influencing spinal manipulative therapy force transmission through the thorax: a cadaveric study. Chiropr Man Therap 2023; 31:24. [PMID: 37550682 PMCID: PMC10405484 DOI: 10.1186/s12998-023-00493-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/16/2023] [Indexed: 08/09/2023] Open
Abstract
BACKGROUND Spinal manipulative therapy (SMT) clinical effects are believed to be linked to its force-time profile characteristics. Previous studies have revealed that the force measured at the patient-table interface is most commonly greater than the one applied at the clinician-patient interface. The factors explaining this force amplification remains unclear. OBJECTIVE To determine the difference between the force applied to a cadaveric specimen's thoracic spine and the resulting force measured by a force-sensing table, as well as to evaluate the relationship between this difference and both the SMT force-time characteristics and the specimens' characteristics. METHODS Twenty-five SMTs with different force-time profiles were delivered by an apparatus at the T7 vertebra of nine human cadaveric specimens lying prone on a treatment table equipped with a force plate. The difference between the force applied by the apparatus and the resulting force measured by the force plate was calculated in absolute force (Fdiff) and as the percentage of the applied force (Fdiff%). Kinematics markers were inserted into T6 to T8 spinous and transverse processes to evaluate vertebral displacements during the SMT thrusts. Mixed-effects linear models were run to evaluate the variance in Fdiff and Fdiff% explained by SMT characteristics (peak force, thrust duration and force application rate), T6 to T8 relative and total displacements, and specimens' characteristics (BMI, height, weight, kyphosis angle, thoracic thickness). RESULTS Sixty percent of the trials showed lower force measured at the force plate than the one applied at T7. Fdiff¸ was significantly predicted (R2marginal = 0.54) by peak force, thrust duration, thoracic thickness and T6-T7 relative displacement in the z-axis (postero-anterior). Fdiff% was significantly predicted (R2marginal = 0.56) by force application rate, thoracic thickness and total T6 displacements. For both dependant variables, thoracic thickness showed the highest R2marginal out of all predictors. CONCLUSION Difference in force between the clinician-patient and the patient-table interfaces is influenced by SMT force-time characteristics and by thoracic thickness. How these differences in force are associated with vertebral displacements remains unclear. Although further studies are needed, clinicians should consider thorax thickness as a possible modulator of forces being transmitted through it during prone SMT procedures.
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Affiliation(s)
- Jérémie Mikhail
- Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada
- Research Group on Neuromusculoskeletal Disorders, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada
| | - Martha Funabashi
- Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada
- Canadian Memorial Chiropractic College, 6100 Leslie St, North York, ON, M2H 3J1, Canada
| | - Stéphane Sobczak
- Research Group on Neuromusculoskeletal Disorders, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada
- Department of Anatomy, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada
- Research Chair in Functional Anatomy, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, QC, G8Z 4M3, Trois-Rivières, Canada
| | - Martin Descarreaux
- Research Group on Neuromusculoskeletal Disorders, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada
- Department of Human Kinetics, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada
| | - Isabelle Pagé
- Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada.
- Research Group on Neuromusculoskeletal Disorders, Université du Québec à Trois-Rivières, 3351 Boul. des Forges, Trois-Rivières, QC, G8Z 4M3, Canada.
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), Centre Intégré Universitaire de Santé et de Services Sociaux de la Capitale-Nationale (CIUSSS-CN), 525 Boul. Wilfrid-Hamel, Québec City, QC, G1M 2S8, Canada.
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13
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Arnold KM, Sicard D, Tschumperlin DJ, Westendorf JJ. Atomic Force Microscopy Micro-Indentation Methods for Determining the Elastic Modulus of Murine Articular Cartilage. SENSORS (BASEL, SWITZERLAND) 2023; 23:1835. [PMID: 36850434 PMCID: PMC9967621 DOI: 10.3390/s23041835] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/20/2023] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
The mechanical properties of biological tissues influence their function and can predict degenerative conditions before gross histological or physiological changes are detectable. This is especially true for structural tissues such as articular cartilage, which has a primarily mechanical function that declines after injury and in the early stages of osteoarthritis. While atomic force microscopy (AFM) has been used to test the elastic modulus of articular cartilage before, there is no agreement or consistency in methodologies reported. For murine articular cartilage, methods differ in two major ways: experimental parameter selection and sample preparation. Experimental parameters that affect AFM results include indentation force and cantilever stiffness; these are dependent on the tip, sample, and instrument used. The aim of this project was to optimize these experimental parameters to measure murine articular cartilage elastic modulus by AFM micro-indentation. We first investigated the effects of experimental parameters on a control material, polydimethylsiloxane gel (PDMS), which has an elastic modulus on the same order of magnitude as articular cartilage. Experimental parameters were narrowed on this control material, and then finalized on wildtype C57BL/6J murine articular cartilage samples that were prepared with a novel technique that allows for cryosectioning of epiphyseal segments of articular cartilage and long bones without decalcification. This technique facilitates precise localization of AFM measurements on the murine articular cartilage matrix and eliminates the need to separate cartilage from underlying bone tissues, which can be challenging in murine bones because of their small size. Together, the new sample preparation method and optimized experimental parameters provide a reliable standard operating procedure to measure microscale variations in the elastic modulus of murine articular cartilage.
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Affiliation(s)
- Katherine M. Arnold
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
| | - Delphine Sicard
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
| | - Daniel J. Tschumperlin
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
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14
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Kang JS, Navindaran K, Phillips J, Kenny K, Moon KS. Characterization of mechanical properties of soft tissues using sub-microscale tensile testing and 3D-Printed sample holder. J Mech Behav Biomed Mater 2023; 138:105581. [PMID: 36463810 DOI: 10.1016/j.jmbbm.2022.105581] [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: 06/12/2022] [Revised: 08/17/2022] [Accepted: 11/16/2022] [Indexed: 11/20/2022]
Abstract
Obtaining the mechanical properties of soft tissues is critical in many medical fields, such as regenerative medicine and surgical simulation training. Although various tissue-characterization methods have been developed, such as AFM, indentation, and elastography, there remain some limitations on their accuracy and validity for measuring small and fragile soft tissues. This paper presents a tensile testing technique to measure the mechanical properties of soft tissues directly and accurately. Tensile testing was chosen as the primary method because of its simple procedure and ability to derive mechanical properties without requiring many assumptions or complicated models. However, tensile testing on soft tissues presents challenges related to gripping the tissue sample without affecting its inherent properties, applying minuscule forces to the sample, and measuring the cross-section area and strain of the sample. To solve these issues, this study presents a sub-micro scale tensile testing system that uses a flexure mechanism and a novel 3D-printed sample holder for gripping the tissue samples. The system also measures tested samples' cross-section area and strain using two high-resolution cameras. The system was validated by testing standard materials and used to characterize the elastic modulus, yield stress, and yield strain of lung tissue slices from six different mice. The results from the validation tests showed a less than 2.5% error for elastic modulus values measured using the tensile tester. At the same time, results from the mice lung tissue measurements revealed qualitative findings that closely matched those seen in the literature and displayed low coefficient of variation values, demonstrating the high repeatability of the system.
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Affiliation(s)
- John S Kang
- The Department of Mechanical Engineering, San Diego State University, San Diego, CA, 92182, CA, USA
| | - Kishev Navindaran
- The Department of Mechanical Engineering, San Diego State University, San Diego, CA, 92182, CA, USA
| | - J Phillips
- The Department of Biology, San Diego State University, San Diego, CA, 92182, CA, USA
| | - K Kenny
- The Department of Biology, San Diego State University, San Diego, CA, 92182, CA, USA
| | - Kee S Moon
- The Department of Mechanical Engineering, San Diego State University, San Diego, CA, 92182, CA, USA.
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15
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Techniques for characterizing mechanical properties of soft tissues. J Mech Behav Biomed Mater 2023; 138:105575. [PMID: 36470112 DOI: 10.1016/j.jmbbm.2022.105575] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/16/2022] [Accepted: 11/15/2022] [Indexed: 11/21/2022]
Abstract
The characterization of soft tissues remains a vital need for various bioengineering and medical fields. Developing areas such as regenerative medicine, robot-aided surgery, and surgical simulations all require accurate knowledge about the mechanical properties of soft tissues to replicate their mechanics. Mechanical properties can be characterized through several different characterization techniques such as atomic force microscopy, compression testing, and tensile testing. However, many of these methods contain considerable differences in ability to accurately characterize the mechanical properties of soft tissues. As a result of these variations, there are often discrepancies in the reported values for numerous studies. This paper reviews common characterization methods that have been applied to obtain the mechanical properties of soft tissues and highlights their advantages as well as disadvantages. The limitations, accuracies, repeatability, in-vivo testing capability, and types of properties measurable for each method are also discussed.
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16
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Silva-Verissimo W, El Louali F, Godio-Raboutet Y, Leblond L, Sourdon J, Rapacchi S, Evin M. Traction mechanical characterization of porcine mitral valve annulus. J Biomech 2023; 146:111396. [PMID: 36459849 DOI: 10.1016/j.jbiomech.2022.111396] [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: 05/20/2022] [Revised: 11/07/2022] [Accepted: 11/16/2022] [Indexed: 11/21/2022]
Abstract
The Mitral Annulus (MA) is an anisotropic, fibrous, flexible and dynamical structure. While MA dynamics are well documented, its passive mechanical properties remain poorly investigated to complete the design of adequate prostheses. Mechanical properties in traction on four sections of the MA (aortic, left, posterior and right segments) were assessed using a traction test system with a 30 N load cell and pulling jaws for sample fixation. Samples were submitted to a 1.5 N pre-load, 10 pre-conditioning cycles. Three strain rates were tested (5 %/min, 7 %/min and 13 %/min), the first two up to 10 % strain and the last until rupture. High-resolution diffusion-MRI provided microstructural mapping of fractional anisotropy and mean diffusion within muscle and collagen fibres. Ten MA from porcine hearts were excised resulting in 40 tested samples, out of which 28 were frozen prior to testing. Freezing samples significantly increased Young Moduli for all strain rates. No significant differences were found between Young Moduli at different strain rates (fresh samples 2.4 ± 1.1 MPa, 3.8 ± 2.2 MPa and 3.1 ± 1.8 MPa for increasing strain rates in fresh samples), while significant differences were found when comparing aortic with posterior and posterior with lateral (p < 0.012). Aortic segments deformed the most (24.1 ± 9.4 %) while lateral segments endured the highest stress (>0.3 MPa), corresponding to higher collagen fraction (0.46) and fractional anisotropy. Passive machinal properties differed between aortic and lateral segments of the MA. The process of freezing samples altered their mechanical properties. Underlying microstructural differences could be linked to changes in strain response.
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Affiliation(s)
| | - F El Louali
- Aix Marseille Univ, Univ Gustave Eiffel, LBA, Marseille, France; AP-HM, Marseille, France
| | | | | | - Joevin Sourdon
- Aix-Marseille University, CNRS, CRMBM, Marseille, France
| | - S Rapacchi
- Aix-Marseille University, CNRS, CRMBM, Marseille, France
| | - Morgane Evin
- Aix Marseille Univ, Univ Gustave Eiffel, LBA, Marseille, France.
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17
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Pukaluk A, Wolinski H, Viertler C, Regitnig P, Holzapfel GA, Sommer G. Changes in the microstructure of the human aortic medial layer under biaxial loading investigated by multi-photon microscopy. Acta Biomater 2022; 151:396-413. [PMID: 35970481 DOI: 10.1016/j.actbio.2022.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/29/2022] [Accepted: 08/08/2022] [Indexed: 11/01/2022]
Abstract
Understanding the correlation between tissue architecture, health status, and mechanical properties is essential for improving material models and developing tissue engineering scaffolds. Since structural-based material models are state of the art, there is an urgent need for experimentally obtained structural parameters. For this purpose, the medial layer of nine human abdominal aortas was simultaneously subjected to equibiaxial loading and multi-photon microscopy. At each loading interval of 0.02, collagen and elastin fibers were imaged based on their second-harmonic generation signal and two-photon excited autofluorescence, respectively. The structural alterations in the fibers were quantified using the parameters of orientation, diameter, and waviness. The results of the mechanical tests divided the sample cohort into the ruptured and non-ruptured, and stiff and non-stiff groups, which were covered by the findings from histological investigations. The alterations in structural parameters provided an explanation for the observed mechanical behavior. In addition, the waviness parameters of both collagen and elastin fibers showed the potential to serve as indicators of tissue strength. The data provided address deficiencies in current material models and bridge multiscale mechanisms in the aortic media. STATEMENT OF SIGNIFICANCE: Available material models can reproduce, but cannot predict, the mechanical behavior of human aortas. This deficiency could be overcome with the help of experimentally validated structural parameters as provided in this study. Simultaneous multi-photon microscopy and biaxial extension testing revealed the microstructure of human aortic media at different stretch levels. Changes in the arrangement of collagen and elastin fibers were quantified using structural parameters such as orientation, diameter and waviness. For the first time, structural parameters of human aortic tissue under continuous loading conditions have been obtained. In particular, the waviness parameters at the reference configuration have been associated with tissue stiffness, brittleness, and the onset of atherosclerosis.
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Affiliation(s)
- Anna Pukaluk
- Institute of Biomechanics, Graz University of Technology, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, University of Graz, Austria; Field of Excellence BioHealth - University of Graz, Austria
| | | | - Peter Regitnig
- Institute of Pathology, Medical University of Graz, Austria
| | - Gerhard A Holzapfel
- Institute of Biomechanics, Graz University of Technology, Austria; Department of Structural Engineering, NTNU, Trondheim, Norway
| | - Gerhard Sommer
- Institute of Biomechanics, Graz University of Technology, Austria.
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18
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Experiments and hyperelastic modeling of porcine meniscus show heterogeneity at high strains. Biomech Model Mechanobiol 2022; 21:1641-1658. [PMID: 35882676 DOI: 10.1007/s10237-022-01611-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 07/01/2022] [Indexed: 11/02/2022]
Abstract
Constitutive modeling of the meniscus is critical in areas like knee surgery and tissue engineering. At low strain rates, the meniscus can be described using a hyperelastic model. Calibration of hyperelastic material models of the meniscus is challenging on many fronts due to material variability and friction. In this study, we present a framework to determine the hyperelastic material parameters of porcine meniscus (and similar soft tissues) using no-slip uniaxial compression experiments. Because of the nonhomogeneous deformation in the specimens, a finite element solution is required at each step of the iterative calibration process. We employ a Bayesian calibration approach to account for the inherent material variability and a Bayesian optimization approach to minimize the resulting cost function in the material parameter space. Cylindrical specimens of porcine meniscus from the anterior, middle and posterior regions are tested up to 30% compressive strain and the Yeoh form of hyperelastic strain energy density function is used to describe the material response. The results show that the Yeoh form is able to accurately describe the compressive response of porcine meniscus and that the Bayesian calibration and optimization approaches are able to calibrate the model in a computationally efficient manner while taking into account the inherent material variability. The results also show that the shear modulus or the initial stiffness is roughly uniform across the different areas of the meniscus, but there is significant spatial heterogeneity in the response at high strains. In particular, the middle region is considerably stiffer at high strains. This heterogeneity is important to consider in modeling the response of the meniscus for clinical applications.
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19
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Koser J, Chirvi S, Banerjee A, Pintar FA, Hampton C, Kleinberger M. Repeated measures analysis of projectile penetration in porcine legs as a function of storage condition. J Forensic Leg Med 2022; 90:102395. [PMID: 35863258 DOI: 10.1016/j.jflm.2022.102395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 12/30/2022]
Abstract
Buried blast explosions create small projectiles which can become lodged in the tissue of personnel as far away as hundreds of meters. Without appropriate treatment, these lodged projectiles can become a source of infection and prolonged injury to soldiers in modern combat. Human cadavers can be used as surrogates for living humans for ballistic penetration testing, but human cadavers are frozen during transport and storage. The process of freezing and thawing the tissue before testing may change the biomechanical properties of the tissue. The goal of the current study was to understand penetration threshold differences between fresh, refrigerated, and frozen tissue and investigate factors that may contribute to these differences. A custom-built pneumatic launcher was used to accelerate 3/16″ stainless steel ball bearings toward porcine legs that were either tested fresh, following refrigerated storage, or following frozen storage. A generalized linear mixed model, accounting for within-animal dependence, owing to repeated observations, was found to be the most appropriate for these data and was used for analysis. The "generalized" model accommodated non-continuous observations, provided a straight-forward way to implement the repeated measures, and provided a risk estimate for projectile penetration. Both storage condition (p = 0.48) and leg (p = 0.07) were shown to be not significant and the confidence intervals for those variables were overlapping. As all covariates were found to be non-significant, a single model containing all impacts was used to develop a V50, or velocity at which 50% of impacts are expected to penetrate. From this model, 50% probability of penetration occurs at 137.3 m/s with 95% confidence intervals at 132.0 and 144.0 m/s. In this study, the fresh legs and previously frozen legs allowed penetration at similar velocities indicating that previously frozen legs were acceptable surrogates for fresh legs. This study only compared the penetration threshold in tissues that had been stored in differing conditions. To truly study penetration, more conditions will need to be studied including the effects of projectile mass and material, the effects of projectile shape, and the effects of clothing or protective layers on penetration threshold.
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Affiliation(s)
- Jared Koser
- Medical College of Wisconsin, Milwaukee, WI, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA; Marquette University, Milwaukee, WI, USA.
| | - Sajal Chirvi
- Medical College of Wisconsin, Milwaukee, WI, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
| | | | - Frank A Pintar
- Medical College of Wisconsin, Milwaukee, WI, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA; Marquette University, Milwaukee, WI, USA
| | - Carolyn Hampton
- DEVCOM Army Research Laboratory, Aberdeen Proving Ground, MD, USA
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20
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van Soldt BJ, Wang T, Filogonio R, Danielsen CC. The mechanical and morphological properties of systemic and pulmonary arteries differ in the earth boa, a snake without ventricular pressure separation. J Exp Biol 2022; 225:275580. [PMID: 35642934 DOI: 10.1242/jeb.244419] [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: 04/13/2022] [Accepted: 05/27/2022] [Indexed: 11/20/2022]
Abstract
The walls of the mammalian aorta and pulmonary artery are characterized by diverging morphologies and mechanical properties, which has been correlated with high systemic and low pulmonary blood pressures, as a result of intraventricular pressure separation. However, the relation between intraventricular pressure separation and diverging aortic and pulmonary artery wall morphologies and mechanical characteristics is not understood. The snake cardiovascular system poses a unique model for the study of this question, since representatives both with and without intraventricular pressure separation exist. In this study we perform uniaxial tensile testing on vessel samples taken from the aortas and pulmonary arteries of the earth boa, Acrantophis madagascariensis, a species without intraventricular pressure separation. We then compare these morphological and mechanical characteristics with samples from the ball python, Python regius, and the yellow anaconda, Eunectes notaeus, species with and without intraventricular pressure separation, respectively. Our data suggest that although the aortas and pulmonary arteries of A. madagascariensis respond similarly to the same intramural blood pressures, they diverge in morphology, and that this attribute extends to E. notaeus. In contrast, P. regius aortas and pulmonary arteries diverge both morphologically and in terms of their mechanical properties. Our data indicate that intraventricular pressure separation cannot fully explain diverging aortic and pulmonary artery morphologies. Following the Law of Laplace, we propose that pulmonary arteries of small luminal diameter represent a mechanism to protect the fragile pulmonary vasculature by reducing the blood volume that passes through, to which genetic factors may contribute more strongly than physiological parameters.
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Affiliation(s)
- Benjamin J van Soldt
- Gladstone Institute of Cardiovascular Disease, J. David Gladstone Institutes, 1650 Owns St, San Francisco, CA, 94158, USA
| | - Tobias Wang
- Aarhus Institute of Advanced Sciences (AIAS), Aarhus University, 8000 Aarhus C, Denmark
| | - Renato Filogonio
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP 13565-905, Brazil
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21
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Cavelier S, Quarrington RD, Jones CF. Mechanical properties of porcine spinal dura mater and pericranium. J Mech Behav Biomed Mater 2021; 126:105056. [PMID: 34953436 DOI: 10.1016/j.jmbbm.2021.105056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND The objective of this study was to characterize and compare the mechanical properties of porcine pericranium and spinal dura mater, to evaluate the mechanical suitability of pericranium as a dural graft. METHOD Eighty-eight spinal dura (cervical, thoracic, and lumbar regions, in ventral longitudinal, dorsal longitudinal and circumferential orientations) and eighteen pericranium samples (ventral-dorsal, and lateral orientations) from four pigs, were harvested and subjected to uniaxial loading while hydrated. The stiffness, strain at toe-linear regions transition, strain at linear-yield regions transition and other structural and mechanical properties were measured. Stress-strain curves were fitted to a one-term Ogden model and Ogden parameters were calculated. Linear regression models with cluster-robust standard errors were used to assess the effect of region and orientation on material and structural properties. RESULTS Both spinal dura and pericranium exhibited distinct anisotropy and were stiffer in the longitudinal direction. The tissues exhibited structural and mechanical similarities especially in terms of stiffness and strains in the linear region. Stiffness ranged from 1.28 to 5.32 N/mm for spinal dura and 2.42-3.90 N/mm for pericranium. In the circumferential and longitudinal directions, the stiffness of spinal dura specimens was statistically similar to that of pericranium in the same orientation. The strain at the upper bound of the linear region of longitudinal pericranium (28.0%) was statistically similar to that of any spinal dura specimens (24.4-32.9%). CONCLUSIONS Autologous pericranium has advantageous physical properties for spinal duraplasty. The present study demonstrated that longitudinally oriented pericranium is mechanically compatible with spinal duraplasty procedures. Autologous pericranium grafts will likely support the mechanical loads transmitted from the spinal dura, but further biomechanical analyses are required to study the effect of the lower yield strain of circumferential pericranium compared to spinal dura. Finally, the Ogden parameters calculated for pericranium, and the spinal dura at each spinal level, will be useful for computational models incorporating these soft tissues.
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Affiliation(s)
- S Cavelier
- Spinal Research Group & Centre for Orthopaedic and Trauma Research, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia; Department of Mechanical Engineering, McGill University, 817 Rue Sherbrooke Ouest, Montréal, QC, H3A 0C3, Canada
| | - R D Quarrington
- Spinal Research Group & Centre for Orthopaedic and Trauma Research, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - C F Jones
- Spinal Research Group & Centre for Orthopaedic and Trauma Research, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia; School of Mechanical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia.
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22
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Chiu P, Lee HP, Dalal AR, Koyano T, Nguyen M, Connolly AJ, Chaudhuri O, Fischbein MP. Relative strain is a novel predictor of aneurysmal degeneration of the thoracic aorta: An ex vivo mechanical study. JVS Vasc Sci 2021; 2:235-246. [PMID: 34806052 PMCID: PMC8585654 DOI: 10.1016/j.jvssci.2021.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 08/28/2021] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE Current guidelines for prophylactic replacement of the thoracic aorta, primarily based on size alone, may not be adequate in identifying patients at risk for either progression of disease or aortic catastrophe. We undertook the current study to determine whether the mechanical properties of the aorta might be able to predict aneurysmal dilatation of the aorta using a clinical database and benchtop mechanical testing of human aortic tissue. METHODS Using over 400 samples from 31 patients, mechanical properties were studied in (a) normal aorta and then (b) between normal and diseased aorta using linear mixed-effects models. A machine learning technique was used to predict aortic growth rate over time using mechanical properties and baseline clinical characteristics. RESULTS Healthy aortic tissue under in vivo loading conditions, after accounting for aortic segment location, had lower longitudinal elastic modulus compared with circumferential elastic modulus: -166.8 kPa (95% confidence interval [CI]: -210.8 to -122.7, P < .001). Fracture toughness was also lower in the longitudinal vs circumferential direction: -201.2 J/m3 (95% CI: -272.9 to -129.5, P < .001). Finally, relative strain was lower in the longitudinal direction compared with the circumferential direction: -0.01 (95% CI: -0.02 to -0.004, P = .002). Patients with diseased aorta, after accounting for segment location and sample direction, had decreased toughness compared with normal aorta, -431.7 J/m3 (95% CI: -628.6 to -234.8, P < .001), and increased relative strain, 0.09 (95% CI: 0.04 to 0.14, P = .003). CONCLUSIONS Increasing relative strain was identified as a novel independent predictor of aneurysmal degeneration. Noninvasive measurement of relative strain may aid in the identification and monitoring of patients at risk for aneurysmal degeneration. (JVS-Vascular Science 2021;2:1-12.). CLINICAL RELEVANCE Aortic aneurysm surveillance and prophylactic surgical recommendations are based on computed tomographic angiogram aortic dimensions and growth rate measurements. However, aortic catastrophes may occur at small sizes, confounding current risk stratification models. Herein, we report that increasing aortic relative strain, that is, greater distensibility, is associated with growth over time, thus potentially identifying patients at risk for dissection/rupture.
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Affiliation(s)
- Peter Chiu
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford University, Stanford, Calif
| | - Hong-Pyo Lee
- Department of Mechanical Engineering, Stanford University, Stanford, Calif
| | - Alex R. Dalal
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford University, Stanford, Calif
| | - Tiffany Koyano
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford University, Stanford, Calif
| | - Marie Nguyen
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford University, Stanford, Calif
| | - Andrew J. Connolly
- Department of Pathology, University of California San Francisco, San Francisco, Calif
| | - Ovijit Chaudhuri
- Department of Mechanical Engineering, Stanford University, Stanford, Calif
| | - Michael P. Fischbein
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford University, Stanford, Calif
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23
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Xuan Y, Wisneski AD, Wang Z, Lum M, Kumar S, Pallone J, Flores N, Inman J, Lai L, Lin J, Guccione JM, Tseng EE, Ge L. Regional biomechanical and failure properties of healthy human ascending aorta and root. J Mech Behav Biomed Mater 2021; 123:104705. [PMID: 34454207 DOI: 10.1016/j.jmbbm.2021.104705] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/19/2021] [Accepted: 07/03/2021] [Indexed: 11/18/2022]
Abstract
PURPOSE Aortic dissection (AD) is a life-threatening event that occurs when the intimal entry tear propagates and separates inner from outer layers of the aorta. Diameter, the current criterion for aneurysm repair, is far from ideal and additional evidence to optimize clinical decision would be extremely beneficial. Biomechanical investigation of the regional failure properties of aortic tissue is essential to understand and proactively prevent AD. We previously studied biaxial mechanical properties of healthy human aorta. In this study, we investigated the regional failure properties of healthy human ascending aorta (AscAo) including sinuses of Valsalva (SOV), and sinotubular junction (STJ). RESULTS A total of 430 intact tissue samples were harvested from 19 healthy donors whose hearts were excluded from heart transplantation. The donors had mean age of 51 ± 11.7 years and nearly equal gender distribution. Samples were excised from aortic regions and subregions at defined locations. Tissue strips were subjected to either biaxial or uniaxial failure testing. Wall thickness varied regionally being thickest at AscAo (2.08 ± 0.66 mm) and thinnest at SOV (1.46 ± 0.31 mm). Biaxial testing demonstrated hyperplastic behavior of aortic tissues. Posterior and lateral STJ subregions were found to be stiffer than anterior and medial subregions in both circumferential and longitudinal directions. Failure stresses were significantly higher in the circumferential than longitudinal directions in each subregion of AscAo, STJ, and SOV. Longitudinal failure stresses were significantly greater in AscAo than those in STJ or SOV. Longitudinal failure stresses in AscAo were much smaller anteriorly than posteriorly, and medially than laterally. CONCLUSIONS The finding of weakest region at the sinotubular junction along the longitudinal direction corroborates clinical observations of that region being commonly involved as the initial site of intimal tear in aortic dissections. Failure stretch ratios correlated to elastic modulus at each region. Furthermore, strong correlation was seen between STJ failure stresses and elastic modulus at physiological pressure along both circumferential and longitudinal directions. Correlating in-vivo aortic elastic modulus based on in-vivo imaging with experimentally determined elastic modulus at physiological pressure and failure stresses may potentially provide valuable information regarding aortic wall strength. Better understanding of aortic biomechanics in normal physiologic and aneurysmal pathologic states may aid in determining risk factors for predicting dissection in patient-specific fashion.
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Affiliation(s)
- Yue Xuan
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Andrew D Wisneski
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Zhongjie Wang
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Matthew Lum
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Shalni Kumar
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Julia Pallone
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Nick Flores
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Justin Inman
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Lilian Lai
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Joanna Lin
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Julius M Guccione
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
| | - Elaine E Tseng
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA.
| | - Liang Ge
- Department of Surgery, University of California San Francisco and San Francisco VA Medical Centers, San Francisco, CA, USA
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24
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Vera L, Muylle S, Van Steenkiste G, Segers P, Decloedt A, Chiers K, van Loon G. Histological and biomechanical properties of systemic arteries in young and old Warmblood horses. PLoS One 2021; 16:e0253730. [PMID: 34252105 PMCID: PMC8274928 DOI: 10.1371/journal.pone.0253730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 06/13/2021] [Indexed: 11/18/2022] Open
Abstract
Arterial rupture is a well-recognized cause of sudden death in horses, which mainly affects older horses. The arterial wall is known to stiffen with age, although the underlying age-related histological and biomechanical changes remain unclear. The purpose of this study was to investigate the effect of aging by histological analysis of the arterial wall and examination of the arterial wall biomechanical properties using an inflation-extension test. Entire circular samples of the proximal and distal aorta, cranial and caudal common carotid, external iliac, femoral and median artery were collected from 6 young (6 years) and 14 old horses (≥15 years). Samples of all arteries were histologically examined and intima media thickness as well as area % of elastin, smooth muscle actin and collagen type I and III were determined. Older horses had a significantly larger intima media thickness and a significantly higher area % of smooth muscle actin compared to young horses. Samples of the proximal and distal aorta, the caudal common carotid and the external iliac artery were mechanically assessed using an in-house developed inflation-extension device with ultrasound analysis. Rupture occurred in a minority of arteries (8/78) at high pressures (between 250-300 mmHg), and mostly occurred in older horses (7/8). Pressure-area, pressure-compliance and pressure-distensibility curves were constructed. A significant difference in the pressure-area curves of the distal aorta, common carotid artery and external iliac artery, the pressure-compliance curves of the proximal aorta and carotid artery and the pressure-distensibility curve of the proximal aorta was observed between young and old horses. Results demonstrate an effect of age on the histological and biomechanical properties of the arterial wall, which might explain why arterial rupture occurs more often in older horses.
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Affiliation(s)
- Lisse Vera
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium
- * E-mail:
| | - Sofie Muylle
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Glenn Van Steenkiste
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium
| | | | - Annelies Decloedt
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium
| | - Koen Chiers
- Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gunther van Loon
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium
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25
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Cunnane CV, Croghan SM, Walsh MT, Cunnane EM, Davis NF, Flood HD, Mulvihill JJE. Cryopreservation of porcine urethral tissue: Storage at -20°C preserves the mechanical, failure and geometrical properties. J Mech Behav Biomed Mater 2021; 119:104516. [PMID: 33932753 DOI: 10.1016/j.jmbbm.2021.104516] [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] [Received: 12/03/2020] [Revised: 03/23/2021] [Accepted: 04/07/2021] [Indexed: 12/21/2022]
Abstract
Cryopreservation is required to preserve the native properties of tissue for prolonged periods of time. In this study, we evaluate the impact that 4 different cryopreservation protocols have on porcine urethral tissue, to identify a protocol that best preserves the native properties of the tissue. The cryopreservation protocols include storage in cryoprotective agents at -20 °C and -80 °C with a slow, gradual, and fast reduction in temperature. To evaluate the effects of cryopreservation, the tissue is mechanically characterised in uniaxial tension and the mechanical properties, failure mechanics, and tissue dimensions are compared fresh and following cryopreservation. The mechanical response of the tissue is altered following cryopreservation, yet the elastic modulus from the high stress, linear region of the Cauchy stress - stretch curves is unaffected by the freezing process. To further investigate the change in mechanical response following cryopreservation, the stretch at different tensile stress values was evaluated, which revealed that storage at -20 °C is the only protocol that does not significantly alter the mechanical properties of the tissue compared to the fresh samples. Conversely, the ultimate tensile strength and the stretch at failure were relatively unaffected by the freezing process, regardless of the cryopreservation protocol. However, there were alterations to the tissue dimensions following cryopreservation that were significantly different from the fresh samples for the tissue stored at -80 °C. Therefore, any study intent on preserving the mechanical, failure, and geometric properties of urethral tissue during cryopreservation should do so by freezing samples at -20 °C, as storage at -80 °C is shown here to significantly alter the tissue properties.
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Affiliation(s)
- Connor V Cunnane
- BioSciBer, Biomaterials Cluster, Bernal Institute, University of Limerick, Limerick, Ireland; School of Engineering, Faculty of Science and Engineering, University of Limerick, Limerick, Ireland
| | | | - Michael T Walsh
- BioSciBer, Biomaterials Cluster, Bernal Institute, University of Limerick, Limerick, Ireland; School of Engineering, Faculty of Science and Engineering, University of Limerick, Limerick, Ireland; Health Research Institute, University of Limerick, Limerick, Ireland
| | | | - Niall F Davis
- Department of Urology, Beaumont Hospital, Dublin, Ireland; Tissue Engineering Research Group, Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Hugh D Flood
- Class Medical Limited, Unit 1 D, Annacotty Business Park, Co. Limerick, Ireland
| | - John J E Mulvihill
- BioSciBer, Biomaterials Cluster, Bernal Institute, University of Limerick, Limerick, Ireland; School of Engineering, Faculty of Science and Engineering, University of Limerick, Limerick, Ireland; Health Research Institute, University of Limerick, Limerick, Ireland.
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26
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Influence of storage time and blending on irradiated sodium alginate–polyethylene oxide films modified by methyl acrylate monomer. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2936-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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27
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Burkert J, Kochová P, Tonar Z, Cimrman R, Blassová T, Jashari R, Fiala R, Špatenka J. The time has come to extend the expiration limit of cryopreserved allograft heart valves. Cell Tissue Bank 2020; 22:161-184. [PMID: 32583302 DOI: 10.1007/s10561-020-09843-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/13/2020] [Indexed: 12/12/2022]
Abstract
Despite the wide choice of commercial heart valve prostheses, cryopreserved semilunar allograft heart valves (C-AHV) are required, and successfully transplanted in selected groups of patients. The expiration limit (EL) criteria have not been defined yet. Most Tissue Establishments (TE) use the EL of 5 years. From physiological, functional, and surgical point of view, the morphology and mechanical properties of aortic and pulmonary roots represent basic features limiting the EL of C-AHV. The aim of this work was to review methods of AHV tissue structural analysis and mechanical testing from the perspective of suitability for EL validation studies. Microscopic structure analysis of great arterial wall and semilunar leaflets tissue should clearly demonstrate cells as well as the extracellular matrix components by highly reproducible and specific histological staining procedures. Quantitative morphometry using stereological grids has proved to be effective, as the exact statistics was feasible. From mechanical testing methods, tensile test was the most suitable. Young's moduli of elasticity, ultimate stress and strain were shown to represent most important AHV tissue mechanical characteristics, suitable for exact statistical analysis. C-AHV are prepared by many different protocols, so as each TE has to work out own EL for C-AHV.
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Affiliation(s)
- Jan Burkert
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Petra Kochová
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic. .,NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Technická 8, Pilsen, Czech Republic.
| | - Zbyněk Tonar
- NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Technická 8, Pilsen, Czech Republic.,Department of Histology and Embryology, Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Karlovarská 48, 301 66, Pilsen, Czech Republic
| | - Robert Cimrman
- NTIS - New Technologies for the Information Society, Faculty of Applied Sciences, University of West Bohemia, Technická 8, Pilsen, Czech Republic
| | - Tereza Blassová
- Department of Histology and Embryology, Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Karlovarská 48, 301 66, Pilsen, Czech Republic
| | - Ramadan Jashari
- European Homograft Bank, Saint-Jean Clinic, Rue du Meridien 100, 1210, Brussels, Belgium
| | - Radovan Fiala
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Jaroslav Špatenka
- Department of Transplantation and Tissue Banking, Czech National Allograft Heart Valve Bank, Department of Cardiovascular Surgery, Motol University Hospital, and Second Faculty of Medicine Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
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28
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Dahis D, Azhari H. Speed of Sound and Attenuation Temperature Dependence of Bovine Brain: Ex Vivo Study. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2020; 39:1175-1186. [PMID: 31868251 DOI: 10.1002/jum.15203] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/30/2019] [Accepted: 11/30/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES Brain treatments using focused ultrasound (FUS) offer a new range of noninvasive transcranial therapies. The acoustic energy deposition during these procedures may induce a temperature elevation in the tissue; therefore, noninvasive thermal monitoring is essential. Magnetic resonance imaging is the current adopted monitoring modality, but its high operational costs and limited availability may hinder the accessibility to FUS treatments. Aiming at the development of a thermometric ultrasound (US) method for the brain, the specific objective of this investigation was to study the acoustic thermal response of the speed of sound (SOS) and attenuation coefficient (AC) of different brain tissues: namely white matter (WM) and cortical matter. METHODS Sixteen ex vivo bovine brain samples were investigated. These included 7 WM and 9 cortical matter samples. The samples were gradually heated to about 45°C and then repeatedly scanned while cooling using a computerized US system in the through-transmission mode. The temperature was simultaneously registered with thermocouples. From the scans, the normalized SOS and AC for both tissues were calculated. RESULTS The results demonstrated a characteristic cooldown temporal behavior for the normalized AC and SOS curves, which were related to the temperature. The SOS curves enabled clear differentiation between the tissue types but depicted more scattered trajectories for the WM tissue. As for the AC curves, the WM depicted a linear behavior in relation to the temperature. However, both tissue types had rather similar temperature patterns. CONCLUSIONS These findings may contribute to the development of a US temperature-monitoring method during FUS procedures.
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Affiliation(s)
- Daniel Dahis
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Haim Azhari
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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Development and Characterization of a Benchtop Corneal Puncture Injury Model. Sci Rep 2020; 10:4218. [PMID: 32144320 PMCID: PMC7060308 DOI: 10.1038/s41598-020-61079-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/11/2020] [Indexed: 12/13/2022] Open
Abstract
During recent military operations, eye-related injuries have risen in frequency due to increased use of explosive weaponry which often result in corneal puncture injuries. These have one of the poorest visual outcomes for wounded soldiers, often resulting in blindness due to the large variations in injury shape, size, and severity. As a result, improved therapeutics are needed which can stabilize the injury site and promote wound healing. Unfortunately, current corneal puncture injury models are not capable of producing irregularly shaped, large, high-speed injuries as seen on the battlefield, making relevant therapeutic development challenging. Here, we present a benchtop corneal puncture injury model for use with enucleated eyes that utilizes a high-speed solenoid device suitable for creating military-relevant injuries. We first established system baselines and ocular performance metrics, standardizing the different aspects of the benchtop model to ensure consistent results and properly account for tissue variability. The benchtop model was evaluated with corneal puncture injury objects up to 4.2 mm in diameter which generated intraocular pressure levels exceeding 1500 mmHg. Overall, the created benchtop model provides an initial platform for better characterizing corneal puncture injuries as seen in a military relevant clinical setting and a realistic approach for assessing potential therapeutics.
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30
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Trabelsi O, Dumas V, Breysse E, Laroche N, Avril S. In vitro histomechanical effects of enzymatic degradation in carotid arteries during inflation tests with pulsatile loading. J Mech Behav Biomed Mater 2020; 103:103550. [PMID: 32090945 DOI: 10.1016/j.jmbbm.2019.103550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 11/17/2019] [Accepted: 11/20/2019] [Indexed: 01/19/2023]
Abstract
In this paper, the objective is to assess the histomechanical effects of collagen proteolysis in arteries under loading conditions reproducing in vivo environment. Thirteen segments of common porcine carotid arteries (8 proximal and 5 distal) were immersed in a bath of bacterial collagenase and tested with a pulsatile tension/inflation machine. Diameter, pressure and axial load were monitored throughout the tests and used to derive the stress-stretch curves and to determine the secant circumferential stiffness. Results were analysed separately for proximal and distal segments, before and after 1, 2 and 3 h of enzymatic degradation. A histological analysis was performed to relate the arterial microstructure to its mechanical behavior under collagen proteolysis. Control (before enzymatic degradation) and treated populations (after 1, 2 or 3 h of enzymatic degradation) were found statistically incomparable, and histology confirmed the alteration of the fibrous structure of collagen bundles induced by the collagenase treatment. A decrease of the secant circumferential stiffness of the arterial wall was noticed mostly at the beginning of the treatment, and was less pronounced after 1 h. These results constitute an important set of enzymatically damaged arteries that can be used to validate biomechanical computational models correlating structure and properties of blood vessels.
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Affiliation(s)
- Olfa Trabelsi
- Mines Saint-Etienne, University of Lyon, INSERM, U1059,Sainbiose, 42023, Saint-Etienne, France; Sorbonne University, University of Technology of Compiègne, CNRS, UMR 7338 BMBI, 60205, Compiègne, France.
| | - Virginie Dumas
- University of Lyon, National School of Engineers of Saint-Etienne, LTDS, UMR 5513 CNRS, 42100, Saint-Etienne, France.
| | - Edouard Breysse
- Mines Saint-Etienne, University of Lyon, INSERM, U1059 Sainbiose, 42023, Saint-Etienne, France.
| | - Norbert Laroche
- University of Lyon, Jean Monnet University, INSERM, U1059 Sainbiose, 42023, Saint-Etienne, France.
| | - Stephane Avril
- Mines Saint-Etienne, University of Lyon, INSERM, U1059 Sainbiose, 42023, Saint-Etienne, France.
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Quitzan JG, Singh A, Beaufrere H, Valverde A, Lillie B, Salahshoor M, Bardelcik A, Saleh TM. Evaluation of the performance of an endoscopic 3-mm electrothermal bipolar vessel sealing device intended for single use after multiple use-and-resterilization cycles. Vet Surg 2020; 49 Suppl 1:O120-O130. [PMID: 32053219 DOI: 10.1111/vsu.13396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/22/2019] [Accepted: 01/18/2020] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To evaluate the performance of an endoscopic 3-mm electrothermal bipolar vessel sealing device (EBVS) intended for single use after multiple use-and-resterilization cycles. STUDY DESIGN Ex vivo study. SAMPLE POPULATION Eight 3-mm EBVS handpieces. METHODS Handpieces were subjected to a maximum of 15 cycles of testing, including simulated surgery, sealing and burst pressure testing of porcine carotid arteries, reprocessing, and hydrogen peroxide plasma resterilization. Failure was defined as two sequential vascular seal leakage events occurring at <250 mm Hg. Histological evaluation, maximum external temperature of the jaws, sealing time, tissue adherence, jaw surface characterization, and mechanical deterioration were studied. Failure rate was analyzed by using a Kaplan-Meier curve. Linear and ordinal logistic mixed models were used to analyze sealing time, handpiece jaw temperature, and adherence score. RESULTS Mean ± SD diameter of arteries was 3.22 ± 0.35 mm. Failure was observed starting at cycle 10 and going up to cycle 13 in 37.5% (3/8) of the handpieces. Tissue adherence increased after each cycle (P < .001). Maximum external temperature (79.8°C ± 13.9°C) and sealing time (1.8 ± 0.5 seconds) were not significantly different throughout cycles up to failure. A flatter surface and large scratches were observed microscopically throughout the jaw surface after repeated use and resterilization. CONCLUSION The 3-mm EBVS handpiece evaluated in this study can be considered safe to use for up to nine reuse-and-resterilization cycles. CLINICAL SIGNIFICANCE These data provide the basis for establishing preliminary guidelines for the reuse and hydrogen peroxide plasma resterilization of an endoscopic 3-mm EBVS handpiece.
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Affiliation(s)
- Juliany Gomes Quitzan
- School of Veterinary Medicine and Animal Science, Sao Paulo State University, Botucatu, Sao Paulo, Brazil.,Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Ameet Singh
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Hugues Beaufrere
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Alexander Valverde
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Brandon Lillie
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Masoomeh Salahshoor
- School of Engineering, College of Engineering and Physical Sciences, University of Guelph, Ontario, Canada
| | - Alexander Bardelcik
- School of Engineering, College of Engineering and Physical Sciences, University of Guelph, Ontario, Canada
| | - Tarek M Saleh
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada
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32
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Frequency dependent viscoelastic properties of porcine brain tissue. J Mech Behav Biomed Mater 2020; 102:103460. [DOI: 10.1016/j.jmbbm.2019.103460] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 09/24/2019] [Accepted: 09/28/2019] [Indexed: 02/06/2023]
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Mutsenko V, Knaack S, Lauterboeck L, Tarusin D, Sydykov B, Cabiscol R, Ivnev D, Belikan J, Beck A, Dipresa D, Lode A, El Khassawna T, Kampschulte M, Scharf R, Petrenko AY, Korossis S, Wolkers WF, Gelinsky M, Glasmacher B, Gryshkov O. Effect of 'in air' freezing on post-thaw recovery of Callithrix jacchus mesenchymal stromal cells and properties of 3D collagen-hydroxyapatite scaffolds. Cryobiology 2020; 92:215-230. [PMID: 31972153 DOI: 10.1016/j.cryobiol.2020.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 12/16/2022]
Abstract
Through enabling an efficient supply of cells and tissues in the health sector on demand, cryopreservation is increasingly becoming one of the mainstream technologies in rapid translation and commercialization of regenerative medicine research. Cryopreservation of tissue-engineered constructs (TECs) is an emerging trend that requires the development of practically competitive biobanking technologies. In our previous studies, we demonstrated that conventional slow-freezing using dimethyl sulfoxide (Me2SO) does not provide sufficient protection of mesenchymal stromal cells (MSCs) frozen in 3D collagen-hydroxyapatite scaffolds. After simple modifications to a cryopreservation protocol, we report on significantly improved cryopreservation of TECs. Porous 3D scaffolds were fabricated using freeze-drying of a mineralized collagen suspension and following chemical crosslinking. Amnion-derived MSCs from common marmoset monkey Callithrix jacchus were seeded onto scaffolds in static conditions. Cell-seeded scaffolds were subjected to 24 h pre-treatment with 100 mM sucrose and slow freezing in 10% Me2SO/20% FBS alone or supplemented with 300 mM sucrose. Scaffolds were frozen 'in air' and thawed using a two-step procedure. Diverse analytical methods were used for the interpretation of cryopreservation outcome for both cell-seeded and cell-free scaffolds. In both groups, cells exhibited their typical shape and well-preserved cell-cell and cell-matrix contacts after thawing. Moreover, viability test 24 h post-thaw demonstrated that application of sucrose in the cryoprotective solution preserves a significantly greater portion of sucrose-pretreated cells (more than 80%) in comparison to Me2SO alone (60%). No differences in overall protein structure and porosity of frozen scaffolds were revealed whereas their compressive stress was lower than in the control group. In conclusion, this approach holds promise for the cryopreservation of 'ready-to-use' TECs.
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Affiliation(s)
- Vitalii Mutsenko
- Institute for Multiphase Processes, Leibniz University Hannover, Hannover, Germany.
| | - Sven Knaack
- Centre for Translational Bone, Joint and Soft Tissue Research, Faculty of Medicine of Technische Universität Dresden, Dresden, Germany
| | - Lothar Lauterboeck
- Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center New Orleans, USA
| | - Dmytro Tarusin
- Institute for Problems of Cryobiology and Cryomedicine, National Academy of Sciences of Ukraine, Kharkiv, Ukraine
| | - Bulat Sydykov
- Institute for Multiphase Processes, Leibniz University Hannover, Hannover, Germany
| | - Ramon Cabiscol
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Dmitrii Ivnev
- Institute of Power Plant Engineering and Heat Transfer, Leibniz University Hannover, Hannover, Germany
| | - Jan Belikan
- Department of Radiology, University Hospital of Giessen Marburg, Giessen, Germany
| | - Annemarie Beck
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Daniele Dipresa
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Anja Lode
- Centre for Translational Bone, Joint and Soft Tissue Research, Faculty of Medicine of Technische Universität Dresden, Dresden, Germany
| | - Thaqif El Khassawna
- Experimental Trauma Surgery, Faculty of Medicine, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Marian Kampschulte
- Department of Radiology, University Hospital of Giessen Marburg, Giessen, Germany
| | - Roland Scharf
- Institute of Power Plant Engineering and Heat Transfer, Leibniz University Hannover, Hannover, Germany
| | - Alexander Yu Petrenko
- Institute for Problems of Cryobiology and Cryomedicine, National Academy of Sciences of Ukraine, Kharkiv, Ukraine
| | - Sotirios Korossis
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany; Centre for Biological Engineering, Wolfson School for Mechanical Electrical and Manufacturing Engineering, University of Loughborough, Loughborough, United Kingdom
| | - Willem F Wolkers
- Institute for Multiphase Processes, Leibniz University Hannover, Hannover, Germany
| | - Michael Gelinsky
- Centre for Translational Bone, Joint and Soft Tissue Research, Faculty of Medicine of Technische Universität Dresden, Dresden, Germany
| | - Birgit Glasmacher
- Institute for Multiphase Processes, Leibniz University Hannover, Hannover, Germany
| | - Oleksandr Gryshkov
- Institute for Multiphase Processes, Leibniz University Hannover, Hannover, Germany
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Wollmann LC, Suss PH, Kraft L, Ribeiro VS, Noronha L, da Costa FDA, Tuon FF. Histological and Biomechanical Characteristics of Human Decellularized Allograft Heart Valves After Eighteen Months of Storage in Saline Solution. Biopreserv Biobank 2020; 18:90-101. [PMID: 31990593 DOI: 10.1089/bio.2019.0106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Background: The best storage preservation method for maintaining the quality and safety of human decellularized allograft heart valves is yet to be established. Objective: The aim of the present study was to evaluate the stability in terms of extracellular matrix (ECM) integrity of human heart valve allografts decellularized using sodium dodecyl sulfate-ethylenediaminetetraacetic acid (SDS-EDTA) and stored for 6, 12, and 18 months. Methods: A total of 70 decellularized aortic and pulmonary valves were analyzed across different storage times (0, 6, 12, and 18 months) for solution pH measurements, histological findings, cytotoxicity assay results, biomechanical test results, and microbiological suitability test results. Continuous data were analyzed using one-way analysis of variance comparing the follow-up times. Results: The pH of the stock solution did not change during the different time points, and no microbial growth occurred up to 18 months. Histological analysis showed that the decellularized allografts did not present deleterious outcomes or signs of structural degeneration in the ECM up to 12 months. The biomechanical properties showed changes over time in different aspects. Allografts stored for 18 months presented lower tensile strength and elasticity than those stored for 12 months (p < 0.05). The microbiological suitability test suggested no residual antimicrobial effects. Conclusion: Changes in the structure and functionality of SDS-EDTA decellularized heart valve allografts occur after 12 months of storage.
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Affiliation(s)
- Luciana Cristina Wollmann
- School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil.,Tissue Bank, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Paula Hansen Suss
- School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Leticia Kraft
- School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | | | - Lúcia Noronha
- School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil.,Experimental Pathology Laboratory, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Francisco Diniz Affonso da Costa
- School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil.,Tissue Bank, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Felipe Francisco Tuon
- School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil.,Tissue Bank, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
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Cavinato C, Badel P, Krasny W, Avril S, Morin C. Experimental Characterization of Adventitial Collagen Fiber Kinematics Using Second-Harmonic Generation Imaging Microscopy: Similarities and Differences Across Arteries, Species and Testing Conditions. MULTI-SCALE EXTRACELLULAR MATRIX MECHANICS AND MECHANOBIOLOGY 2020. [DOI: 10.1007/978-3-030-20182-1_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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The status and challenges of replicating the mechanical properties of connective tissues using additive manufacturing. J Mech Behav Biomed Mater 2019; 103:103544. [PMID: 32090944 DOI: 10.1016/j.jmbbm.2019.103544] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/29/2019] [Accepted: 11/16/2019] [Indexed: 01/23/2023]
Abstract
The ability to fabricate complex structures via precise and heterogeneous deposition of biomaterials makes additive manufacturing (AM) a leading technology in the creation of implants and tissue engineered scaffolds. Connective tissues (CTs) remain attractive targets for manufacturing due to their "simple" tissue compositions that, in theory, are replicable through choice of biomaterial(s) and implant microarchitecture. Nevertheless, characterisation of the mechanical and biological functions of 3D printed constructs with respect to their host tissues is often limited and remains a restriction towards their translation into clinical practice. This review aims to provide an update on the current status of AM to mimic the mechanical properties of CTs, with focus on arterial tissue, articular cartilage and bone, from the perspective of printing platforms, biomaterial properties, and topological design. Furthermore, the grand challenges associated with the AM of CT replacements and their subsequent regulatory requirements are discussed to aid further development of reliable and effective implants.
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Ayyalasomayajula V, Pierrat B, Badel P. A computational model for understanding the micro-mechanics of collagen fiber network in the tunica adventitia. Biomech Model Mechanobiol 2019; 18:1507-1528. [PMID: 31065952 PMCID: PMC6748894 DOI: 10.1007/s10237-019-01161-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 04/26/2019] [Indexed: 12/11/2022]
Abstract
Abdominal aortic aneurysm is a prevalent cardiovascular disease with high mortality rates. The mechanical response of the arterial wall relies on the organizational and structural behavior of its microstructural components, and thus, a detailed understanding of the microscopic mechanical response of the arterial wall layers at loads ranging up to rupture is necessary to improve diagnostic techniques and possibly treatments. Following the common notion that adventitia is the ultimate barrier at loads close to rupture, in the present study, a finite element model of adventitial collagen network was developed to study the mechanical state at the fiber level under uniaxial loading. Image stacks of the rabbit carotid adventitial tissue at rest and under uniaxial tension obtained using multi-photon microscopy were used in this study, as well as the force-displacement curves obtained from previously published experiments. Morphological parameters like fiber orientation distribution, waviness, and volume fraction were extracted for one sample from the confocal image stacks. An inverse random sampling approach combined with a random walk algorithm was employed to reconstruct the collagen network for numerical simulation. The model was then verified using experimental stress-stretch curves. The model shows the remarkable capacity of collagen fibers to uncrimp and reorient in the loading direction. These results further show that at high stretches, collagen network behaves in a highly non-affine manner, which was quantified for each sample. A comprehensive parameter study to understand the relationship between structural parameters and their influence on mechanical behavior is presented. Through this study, the model was used to conclude important structure-function relationships that control the mechanical response. Our results also show that at loads close to rupture, the probability of failure occurring at the fiber level is up to 2%. Uncertainties in usually employed rupture risk indicators and the stochastic nature of the event of rupture combined with limited knowledge on the microscopic determinants motivate the development of such an analysis. Moreover, this study will advance the study of coupling microscopic mechanisms to rupture of the artery as a whole.
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Affiliation(s)
- Venkat Ayyalasomayajula
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 SAINBIOSE, Centre CIS, 42023, Saint-Étienne, France.
| | - Baptiste Pierrat
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 SAINBIOSE, Centre CIS, 42023, Saint-Étienne, France
| | - Pierre Badel
- Mines Saint-Étienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 SAINBIOSE, Centre CIS, 42023, Saint-Étienne, France
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Chim YH, Davies HA, Mason D, Nawaytou O, Field M, Madine J, Akhtar R. Bicuspid valve aortopathy is associated with distinct patterns of matrix degradation. J Thorac Cardiovasc Surg 2019; 160:e239-e257. [PMID: 31679706 PMCID: PMC7674632 DOI: 10.1016/j.jtcvs.2019.08.094] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/16/2019] [Accepted: 08/21/2019] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To explore the micromechanical, biochemical, and microstructural differences between bicuspid aortic valve aneurysm (BAV-A) and tricuspid aortic valve idiopathic degenerative aneurysm (DA), compared with normal aorta. METHODS Aortic tissue was obtained from patients undergoing aneurysmal repair surgery (BAV-A; n = 15 and DA; n = 15). Control tissue was obtained from aortic punch biopsies during coronary artery bypass graft surgery (n = 9). Nanoindentation was used to determine the elastic modulus on the medial layer. Glycosaminoglycan, collagen, and elastin levels were measured using biochemical assays. Verhoeff Van Gieson-stained cross-sections were imaged for elastin microstructural quantification. RESULTS The elastic modulus was more than 20% greater for BAV-A relative to control and DA (signifying a loss of compliance). No significance difference between control and DA were observed. Collagen levels for BAV-A (36.9 ± 7.4 μg/mg) and DA (49.9 ± 10.9 μg/mg) were greater compared with the control (30.2 ± 13.1 μg/mg). Glycosaminoglycan and elastin levels were not significant between the groups. Elastin segments were uniform throughout the control. Aneurysmal tissues had less elastin segments close to the intima and adventitia layers. Both BAV-A and DA had elastin segments compacted in the media; however, elastin segments were highly fragmented in DA. CONCLUSIONS BAV-A has a greater loss of aortic wall compliance relative to DA and the control. Although elastin levels were equal for all groups, spatial distribution of elastin provided a unique profile of matrix degradation for BAV-A. Elastin compaction within the media of BAV-A may have resulted from the altered hemodynamic pressure against the wall, which could explain for the stiffness of the tissue.
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Affiliation(s)
- Ya Hua Chim
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, United Kingdom
| | - Hannah A Davies
- Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom; Liverpool Centre for Cardiovascular Sciences, University of Liverpool, Liverpool, United Kingdom
| | - David Mason
- Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Omar Nawaytou
- Department of Cardiac Surgery, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
| | - Mark Field
- Liverpool Centre for Cardiovascular Sciences, University of Liverpool, Liverpool, United Kingdom; Department of Cardiac Surgery, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
| | - Jillian Madine
- Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom; Liverpool Centre for Cardiovascular Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Riaz Akhtar
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, United Kingdom; Liverpool Centre for Cardiovascular Sciences, University of Liverpool, Liverpool, United Kingdom.
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Effect of inflammation on the biomechanical strength of involved aorta in type A aortic dissection and ascending thoracic aortic aneurysm: An initial research. Anatol J Cardiol 2019; 20:85-92. [PMID: 30088482 PMCID: PMC6237950 DOI: 10.14744/anatoljcardiol.2018.49344] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE Type A aortic dissection (AD) and ascending thoracic aortic aneurysm (AA) are thoracic vascular diseases with similar initial pathology but inequable clinical features and outcomes, where local and systemic inflammation play an important part. We aimed to observe and analyze the differences and correlation between inflammation and pathological changes in the aorta and biomechanical strength between AD and AA. METHODS From August 2011 to February 2013, 20 patients with AD (AD group) and 13 patients with AA (AA group) who underwent aorta surgery were included. Serum concentrations of total cholesterol (TC), triglycerides (TG), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels were measured just before surgical anesthesia. The longitudinal vessel samples of the affected ascending aorta were harvested during surgery and prepared for subsequent pathological observation and uniaxial tension test to measure the longitudinal tensile strength (TS). Samples were also prepared for further measurement of tissue homogenized TNF-α and IL-6 concentrations. RESULTS No significant difference was seen between the two groups with respect to baseline data, and the serum concentrations of TC and TG of both the groups were within the normal range (p>0.05). Blood and tissue homogenized levels of IL-6 and TNF-α were significantly higher in the AD group than in the AA group (p<0.001). Pathological observation of the aortic tissue showed more inflammatory cells infiltration and elastic fiber destruction in the AD group than in the AA group, indicating significant aortic medial degeneration. Uniaxial tensile tests showed that the longitudinal TS was significant lower in the AD group than in the AA group (p<0.001). The longitudinal TS showed negative correlations with serum and tissue homogenized concentrations of IL-6 and TNF-α in the AD group (p<0.05), whereas no such significant correlation was seen in the AA group. CONCLUSION Patients with AD had acute systemic inflammation, along with acute inflammation and declined biomechanical strength of the affected aorta. The serum and tissue homogenized concentrations of IL-6 and TNF-α showed a significant correlation with the biomechanical strength of affected aorta in AD.
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Vishwakarma SK, Lakkireddy C, Bardia A, Paspala SAB, Khan AA. Engineering bio-mimetic humanized neurological constructs using acellularized scaffolds of cryopreserved meningeal tissues. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 102:34-44. [PMID: 31147006 DOI: 10.1016/j.msec.2019.04.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/14/2019] [Accepted: 04/11/2019] [Indexed: 12/21/2022]
Abstract
Spinal cord injury (SCI) is one of the most precarious conditions which have been one of the major reasons for continuous increasing mortality rate of SCI patients. Currently, there is no effective treatment modality for SCI patients posing major threat to the scientific and medical community. The available strategies don't mimic with the natural processes of nervous tissues repair/regeneration and majority of the approaches may induce the additional fibrotic or immunological response at the injury site and are not readily available on demand. To overcome these hurdles, we have developed a ready to use bioengineered human functional neurological construct (BHNC) for regenerative applications in SCI defects. We used cryopreserved meningeal tissues (CMT) for bioengineering these neurological constructs using acellularization and repopulation technology. The technology adopted herein generates intact neurological scaffolds from CMT and retains several crucial structural, biochemical and mechanical cues to enhance the regenerative mechanisms. The neurogenic differentiation on CMT scaffolds was almost similar to the freshly prepared meningeal scaffolds and mimics with the natural nervous tissue developmental mechanisms which offer intact 3D-microarchitecture and hospitable microenvironment enriched with several crucial neurotrophins for long-term cell survival and function. Functional assessment of developed BHNC showed highly increased positive staining for pre-synaptic granules of Synapsis-1 along with MAP-2 antibody with punctuate distribution in axonal regions of the neuronal cells which was well supported by the gene expression analysis of functional transcripts. Given the significant improvement in the field may enable to generate more such ready to use functional BHNC for wider applicability in SCI repair/regeneration.
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Affiliation(s)
- Sandeep Kumar Vishwakarma
- Central Laboratory for Stem Cell Research and Translational Medicine, Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad 500058, Telangana, India; Dr Habeebullah Life Sciences, Attapur, Hyderabad, Telangana, India
| | - Chandrakala Lakkireddy
- Central Laboratory for Stem Cell Research and Translational Medicine, Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad 500058, Telangana, India; Dr Habeebullah Life Sciences, Attapur, Hyderabad, Telangana, India
| | - Avinash Bardia
- Central Laboratory for Stem Cell Research and Translational Medicine, Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad 500058, Telangana, India; Dr Habeebullah Life Sciences, Attapur, Hyderabad, Telangana, India
| | - Syed Ameer Basha Paspala
- Central Laboratory for Stem Cell Research and Translational Medicine, Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad 500058, Telangana, India; Dr Habeebullah Life Sciences, Attapur, Hyderabad, Telangana, India
| | - Aleem Ahmed Khan
- Central Laboratory for Stem Cell Research and Translational Medicine, Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad 500058, Telangana, India; Dr Habeebullah Life Sciences, Attapur, Hyderabad, Telangana, India.
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Javid F, Shahmansouri N, Angeles J, Mongrain R. Fatigue exhaustion of the mitral valve tissue. Biomech Model Mechanobiol 2018; 18:89-97. [PMID: 30097813 DOI: 10.1007/s10237-018-1070-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 08/02/2018] [Indexed: 11/24/2022]
Abstract
Sudden failure and rupture of the tissue is a rare but serious short-term complication after the mitral valve surgical repair. Excessive cyclic loading on the suture line of the repair can progressively damage the surrounding tissue and finally cause tissue rupture. Moreover, mechanical over-tension, which occurs in a diseased mitral valve, gradually leads to tissue floppiness, mitral annular dilation, and leaflet rupture. In this work, the rupture mechanics of mitral valve is studied by characterizing the fracture toughness exhaustion of healthy tissue. Results of this study show that fracture toughness of the posterior mitral valve is lower than its anterior counterpart, indicating that posterior tissue is more prone to failure. Moreover, the decrease in fracture toughness by increasing the number of fatigue cycles shows that excessive mechanical loading leads to progressive failure and rupture of mitral valve tissue within a damage accumulative process.
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Affiliation(s)
- Farhad Javid
- Koch Institute for Cancer Research, Massachusetts Institute of Technology, 500 Main St., Cambridge, MA, 02140, USA.
| | - Nastaran Shahmansouri
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke St. W., Montreal, Quebec, H3A 0C3, Canada
| | - Jorge Angeles
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke St. W., Montreal, Quebec, H3A 0C3, Canada.,Department of Mechanical Engineering, Centre for Intelligent Machines, McGill University, 3480 University Street, Montreal, Quebec, H3A 2A7, Canada
| | - Rosaire Mongrain
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke St. W., Montreal, Quebec, H3A 0C3, Canada
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Wilczek P, Paulina G, Karolina J, Martyna M, Grazyna W, Roman M, Aldona M, Anna S, Aneta S. Biomechanical and morphological stability of acellular scaffolds for tissue-engineered heart valves depends on different storage conditions. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:106. [PMID: 29971508 PMCID: PMC6028870 DOI: 10.1007/s10856-018-6106-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 06/14/2018] [Indexed: 06/08/2023]
Abstract
Currently available bioprosthetic heart valves have been successfully used clinically; however, they have several limitations. Alternatively, tissue-engineering techniques can be used. However, there are limited data concerning the impact of storage conditions of scaffolds on their biomechanics and morphology. The aim of this study was to determine the effect of different storage conditions on the biomechanics and morphology of pulmonary valve dedicated for the acellular scaffold preparation to achieve optimal conditions to obtain stable heart valve prostheses. Scaffold can then be used for the construction of tissue-engineered heart valve, for this reason evaluation of these parameters can determine the success of the clinical application this type of bioprosthesis. Pulmonary heart valves were collected from adult porcines. Materials were divided into five groups depending on the storage conditions. Biomechanical tests were performed, both the static tensile test, and examination of viscoelastic properties. Extracellular matrix morphology was evaluated using transmission electron microscopy and immunohistochemistry. Tissue stored at 4 °C exhibited a higher modulus of elasticity than the control (native) and fresh acellular, which indicated the stiffening of the tissue and changes of the viscoelastic properties. Such changes were not observed in the radial direction. Percent strain was not significantly different in the study groups. The storage conditions affected the acellularization efficiency and tissue morphology. To the best of our knowledge, this study is the first that attributes the mechanical properties of pulmonary valve tissue to the biomechanical changes in the collagen network due to different storage conditions. Storage conditions of scaffolds for tissue-engineered heart valves may have a significant impact on the haemodynamic and clinical effects of the used bioprostheses.
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Affiliation(s)
- Piotr Wilczek
- Heart Prosthesis Institute, Bioengineering Laboratory, Wolnosci 345A, 41-800, Zabrze, Poland.
| | - Gach Paulina
- Heart Prosthesis Institute, Bioengineering Laboratory, Wolnosci 345A, 41-800, Zabrze, Poland
| | - Jendryczko Karolina
- Heart Prosthesis Institute, Bioengineering Laboratory, Wolnosci 345A, 41-800, Zabrze, Poland
| | - Marcisz Martyna
- Heart Prosthesis Institute, Bioengineering Laboratory, Wolnosci 345A, 41-800, Zabrze, Poland
| | - Wilczek Grazyna
- Department of Animal Physiology and Ecotoxicology, Faculty of Biology and Environmental Protection, University of Silesia, Bankowa 9, 40-007, Katowice, Poland
| | - Major Roman
- Institute of Metallurgy and Materials Science, Reymonta 24, 30-059, Krakow, Poland
| | - Mzyk Aldona
- Institute of Metallurgy and Materials Science, Reymonta 24, 30-059, Krakow, Poland
| | - Sypien Anna
- Institute of Metallurgy and Materials Science, Reymonta 24, 30-059, Krakow, Poland
| | - Samotus Aneta
- Heart Prosthesis Institute, Bioengineering Laboratory, Wolnosci 345A, 41-800, Zabrze, Poland
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43
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Hohmann E, Keough N, Glatt V, Tetsworth K, Putz R, Imhoff A. The mechanical properties of fresh versus fresh/frozen and preserved (Thiel and Formalin) long head of biceps tendons: A cadaveric investigation. Ann Anat 2018; 221:186-191. [PMID: 29879483 DOI: 10.1016/j.aanat.2018.05.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/09/2018] [Accepted: 05/02/2018] [Indexed: 11/16/2022]
Abstract
Human cadaveric specimens commonly serve as mechanical models and as biological tissue donors in basic biomechanical research. Although these models are used to explain both in vitro and in vivo behavior, the question still remains whether the specimens employed reflect the normal in vivo situation. The mechanical properties of fresh-frozen or preserved cadavers may differ, and whether they can be used to reliably investigate pathology could be debated. The purpose of this study was to therefore examine the mechanical properties of cadaveric long biceps tendons, comparing fresh (n=7) with fresh-frozen (n=8), formalin embalmed (n=15), and Thiel-preserved (n=6) specimens using a Universal Testing Machine. The modulus of elasticity and the ultimate tensile strength to failure was recorded. Tensile failure occurred at an average of 12N/mm2 in the fresh group, increasing to 40.1N/mm2 in the fresh-frozen group, 50.3N/mm2 in the formalin group, and 52N/mm2 in the Thiel group. The modulus of elasticity/stiffness of the tendon increased from fresh (25.6MPa), to fresh-frozen (55.3MPa), to Thiel (82.5MPa), with the stiffest being formalin (510.6MPa). Thiel-preserved and formalin-embalmed long head of biceps tendons and fresh-frozen tendons have a similar load to failure. Either the Thiel or formalin preserved tendon could therefore be considered as alternatives for load to failure studies. However, the Young's modulus of embalmed tendons were significantly stiffer than fresh or fresh frozen specimens, and these methods might be less suitable alternatives when viscoelastic properties are being investigated.
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Affiliation(s)
- Erik Hohmann
- School of Medicine, Faculty of Health Sciences, University of Pretoria, South Africa; Valiant Clinic, Houston Methodist Group.
| | - Natalie Keough
- Department of Anatomy, School of Medicine, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Vaida Glatt
- Department of Orthopaedic Surgery, University of Texas Health Science Center, San Antonio, TX, USA
| | - Kevin Tetsworth
- Department of Orthopaedic Surgery, Royal Brisbane Hospital, Herston, Australia; Orthopaedic Research Centre of Australia, Brisbane, Queensland, Australia
| | - Reinhard Putz
- Institute of Anatomy, Ludwig-Maximilian-University, Munich, Germany
| | - Andreas Imhoff
- Department of Orthopaedic Sports Medicine, Technical University of Munich, Germany
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44
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Histological and mechanical evaluation of antifreeze peptide (Afp1m) cryopreserved skin grafts post transplantation in a rat model. Cryobiology 2018; 82:27-36. [PMID: 29679551 DOI: 10.1016/j.cryobiol.2018.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/27/2018] [Accepted: 04/17/2018] [Indexed: 11/22/2022]
Abstract
The objective of this study was to evaluate the use of Afp1m as a cryopreservative agent for skin by examining the transplanted skin histological architecture and mechanical properties following subzero cryopreservation. Thirty four (34) rats with an average weight of 208 ± 31 g (mean ± SD), were used. Twenty four (n = 24) rats were equally divided into four groups: (i) immediate non-cryopreserved skin autografts (onto same site), (ii) immediate non-cryopreserved skin autografts (onto different sites), (iii) skin autografts cryopreserved with glycerol for 72 h and (iv) skin autografts cryopreserved with Afp1m for 72 h at -4 °C. Rounded shaped full-thickness 1.5-2.5 cm in diameter skin was excised from backs of rats for the autograft transplantation. Non-cryopreserved or cryopreserved auto skin graft were positioned onto the wound defects and stitched. Non-transplanted cryopreserved and non-cryopreserved skin strips from other ten rats (n = 10) were allowed for comparative biomechanical test. All skin grafts were subjected to histological and mechanical examinations at the end of day 21. Histological results revealed that tissue architecture especially the epidermal integrity and dermal-epidermal junction of the Afp1m cryopreserved skin grafts exhibited better histological appearance, good preservation of tissue architecture and structural integrity than glycerolized skin. However, there was no significant difference among these groups in other histological criteria. There were no significant differences among the 4 groups in skin graft mechanical properties namely maximum load. In conclusion, Afp1m were found to be able to preserve the microstructure as well as the viability and function of the skin destined for skin transplantation when was kept at -4 °C for 72 h.
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45
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Singal A, Mattison LM, Soule CL, Ballard JR, Rudie EN, Cressman ENK, Iaizzo PA. Assessment of Ablative Therapies in Swine: Response of Respiratory Diaphragm to Varying Doses. Ann Biomed Eng 2018; 46:947-959. [PMID: 29594687 DOI: 10.1007/s10439-018-2014-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 03/22/2018] [Indexed: 11/29/2022]
Abstract
Ablation is a common procedure for treating patients with cancer, cardiac arrhythmia, and other conditions, yet it can cause collateral injury to the respiratory diaphragm. Collateral injury can alter the diaphragm's properties and/or lead to respiratory dysfunction. Thus, it is important to understand the diaphragm's physiologic and biomechanical properties in response to ablation therapies, in order to better understand ablative modalities, minimize complications, and maximize the safety and efficacy of ablative procedures. In this study, we analyzed physiologic and biomechanical properties of swine respiratory diaphragm muscle bundles when exposed to 5 ablative modalities. To assess physiologic properties, we performed in vitro tissue bath studies and measured changes in peak force and baseline force. To assess biomechanical properties, we performed uniaxial stress tests, measuring force-displacement responses, stress-strain characteristics, and avulsion forces. After treating the muscle bundles with all 5 ablative modalities, we observed dose-dependent sustained reductions in peak force and transient increases in baseline force-but no consistent dose-dependent biomechanical responses. These data provide novel insights into the effects of various ablative modalities on the respiratory diaphragm, insights that could enable improvements in ablative techniques and therapies.
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Affiliation(s)
- Ashish Singal
- Departments of Surgery and Biomedical Engineering, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA.,Institute for Engineering in Medicine, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA
| | - Lars M Mattison
- Departments of Surgery and Biomedical Engineering, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA.,Institute for Engineering in Medicine, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA
| | - Charles L Soule
- Departments of Surgery and Biomedical Engineering, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA
| | - John R Ballard
- Departments of Surgery and Biomedical Engineering, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA
| | - Eric N Rudie
- Departments of Surgery and Biomedical Engineering, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA
| | - Erik N K Cressman
- Departments of Surgery and Biomedical Engineering, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA
| | - Paul A Iaizzo
- Departments of Surgery and Biomedical Engineering, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA. .,Institute for Engineering in Medicine, University of Minnesota, 420 Delaware St. SE, B172 Mayo, MMC 195, Minneapolis, MN, 55455, USA.
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46
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Smoljkić M, Verbrugghe P, Larsson M, Widman E, Fehervary H, D'hooge J, Vander Sloten J, Famaey N. Comparison of in vivo vs. ex situ obtained material properties of sheep common carotid artery. Med Eng Phys 2018; 55:16-24. [PMID: 29580793 DOI: 10.1016/j.medengphy.2018.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 03/02/2018] [Accepted: 03/13/2018] [Indexed: 11/29/2022]
Abstract
Patient-specific biomechanical modelling can improve preoperative surgical planning. This requires patient-specific geometry as well as patient-specific material properties as input. The latter are, however, still quite challenging to estimate in vivo. This study focuses on the estimation of the mechanical properties of the arterial wall. Firstly, in vivo pressure, diameter and thickness of the arterial wall were acquired for sheep common carotid arteries. Next, the animals were sacrificed and the tissue was stored for mechanical testing. Planar biaxial tests were performed to obtain experimental stress-stretch curves. Finally, parameters for the hyperelastic Mooney-Rivlin and Gasser-Ogden-Holzapfel (GOH) material model were estimated based on the in vivo obtained pressure-diameter data as well as on the ex situ experimental stress-stretch curves. Both material models were able to capture the in vivo behaviour of the tissue. However, in the ex situ case only the GOH model provided satisfactory results. When comparing different fitting approaches, in vivo vs. ex situ, each of them showed its own advantages and disadvantages. The in vivo approach estimates the properties of the tissue in its physiological state while the ex situ approach allows to apply different loadings to properly capture the anisotropy of the tissue. Both of them could be further enhanced by improving the estimation of the stress-free state, i.e. by adding residual circumferential stresses in vivo and by accounting for the flattening effect of the tested samples ex vivo. • Competing interests: none declared • Word count: 4716.
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Affiliation(s)
- Marija Smoljkić
- Biomechanics Section, Mechanical Engineering Department, KU Leuven, Leuven, Belgium
| | - Peter Verbrugghe
- Clinical Cardiac Surgery, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Matilda Larsson
- School of Technology and Health, Department of Medical Engineering, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Erik Widman
- School of Technology and Health, Department of Medical Engineering, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Heleen Fehervary
- Biomechanics Section, Mechanical Engineering Department, KU Leuven, Leuven, Belgium
| | - Jan D'hooge
- Cardiovascular Imaging and Dynamics, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Jos Vander Sloten
- Biomechanics Section, Mechanical Engineering Department, KU Leuven, Leuven, Belgium
| | - Nele Famaey
- Clinical Cardiac Surgery, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
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47
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Wang Y, Li H, Zhang Y. Understanding the viscoelastic behavior of arterial elastin in glucose via relaxation time distribution spectrum. J Mech Behav Biomed Mater 2018; 77:634-641. [DOI: 10.1016/j.jmbbm.2017.10.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 10/10/2017] [Accepted: 10/16/2017] [Indexed: 01/05/2023]
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48
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Farotto D, Segers P, Meuris B, Vander Sloten J, Famaey N. The role of biomechanics in aortic aneurysm management: requirements, open problems and future prospects. J Mech Behav Biomed Mater 2018; 77:295-307. [DOI: 10.1016/j.jmbbm.2017.08.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/09/2017] [Accepted: 08/15/2017] [Indexed: 12/18/2022]
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49
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Wei JCJ, Edwards GA, Martin DJ, Huang H, Crichton ML, Kendall MAF. Allometric scaling of skin thickness, elasticity, viscoelasticity to mass for micro-medical device translation: from mice, rats, rabbits, pigs to humans. Sci Rep 2017; 7:15885. [PMID: 29162871 PMCID: PMC5698453 DOI: 10.1038/s41598-017-15830-7] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 11/02/2017] [Indexed: 12/23/2022] Open
Abstract
Emerging micro-scale medical devices are showing promise, whether in delivering drugs or extracting diagnostic biomarkers from skin. In progressing these devices through animal models towards clinical products, understanding the mechanical properties and skin tissue structure with which they interact will be important. Here, through measurement and analytical modelling, we advanced knowledge of these properties for commonly used laboratory animals and humans (~30 g to ~150 kg). We hypothesised that skin's stiffness is a function of the thickness of its layers through allometric scaling, which could be estimated from knowing a species' body mass. Results suggest that skin layer thicknesses are proportional to body mass with similar composition ratios, inter- and intra-species. Experimental trends showed elastic moduli increased with body mass, except for human skin. To interpret the relationship between species, we developed a simple analytical model for the bulk elastic moduli of skin, which correlated well with experimental data. Our model suggest that layer thicknesses may be a key driver of structural stiffness, as the skin layer constituents are physically and therefore mechanically similar between species. Our findings help advance the knowledge of mammalian skin mechanical properties, providing a route towards streamlined micro-device research and development onto clinical use.
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Affiliation(s)
- Jonathan C J Wei
- Delivery of Drugs and Genes Group (D2G2), Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia QLD, 4072, Australia
| | - Grant A Edwards
- Martin group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia QLD, 4072, Australia
| | - Darren J Martin
- Martin group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia QLD, 4072, Australia
| | - Han Huang
- Nanomechanics and Nanomanufacturing Group, School of Mechanical and Mining Engineering, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia QLD, 4072, Australia
| | - Michael L Crichton
- Delivery of Drugs and Genes Group (D2G2), Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia QLD, 4072, Australia.
- Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom.
| | - Mark A F Kendall
- Delivery of Drugs and Genes Group (D2G2), Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia QLD, 4072, Australia.
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland, St Lucia QLD, 4072, Australia.
- Faculty of Medicine, The University of Queensland, Royal Brisbane and Women's Hospital, Herston QLD, 4006, Australia.
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50
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Seydewitz R, Menzel R, Siebert T, Böl M. Three-dimensional mechano-electrochemical model for smooth muscle contraction of the urinary bladder. J Mech Behav Biomed Mater 2017; 75:128-146. [DOI: 10.1016/j.jmbbm.2017.03.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/22/2017] [Accepted: 03/31/2017] [Indexed: 11/25/2022]
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