1
|
Liu X, Deng Y, Liang Z, Qiao D, Zhang W, Wang M, Li F, Liu J, Wu Y, Chen G, Liu Y, Tan W, Xing J, Huang W, Zhao D, Li Y. The alteration of the structure and macroscopic mechanical response of porcine patellar tendon by elastase digestion. Front Bioeng Biotechnol 2024; 12:1374352. [PMID: 38694621 PMCID: PMC11061363 DOI: 10.3389/fbioe.2024.1374352] [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: 01/22/2024] [Accepted: 04/01/2024] [Indexed: 05/04/2024] Open
Abstract
Background: The treatment of patellar tendon injury has always been an unsolved problem, and mechanical characterization is very important for its repair and reconstruction. Elastin is a contributor to mechanics, but it is not clear how it affects the elasticity, viscoelastic properties, and structure of patellar tendon. Methods: The patellar tendons from six fresh adult experimental pigs were used in this study and they were made into 77 samples. The patellar tendon was specifically degraded by elastase, and the regional mechanical response and structural changes were investigated by: (1) Based on the previous study of elastase treatment conditions, the biochemical quantification of collagen, glycosaminoglycan and total protein was carried out; (2) The patellar tendon was divided into the proximal, central, and distal regions, and then the axial tensile test and stress relaxation test were performed before and after phosphate-buffered saline (PBS) or elastase treatment; (3) The dynamic constitutive model was established by the obtained mechanical data; (4) The structural relationship between elastin and collagen fibers was analyzed by two-photon microscopy and histology. Results: There was no statistical difference in mechanics between patellar tendon regions. Compared with those before elastase treatment, the low tensile modulus decreased by 75%-80%, the high tensile modulus decreased by 38%-47%, and the transition strain was prolonged after treatment. For viscoelastic behavior, the stress relaxation increased, the initial slope increased by 55%, the saturation slope increased by 44%, and the transition time increased by 25% after enzyme treatment. Elastin degradation made the collagen fibers of patellar tendon become disordered and looser, and the fiber wavelength increased significantly. Conclusion: The results of this study show that elastin plays an important role in the mechanical properties and fiber structure stability of patellar tendon, which supplements the structure-function relationship information of patellar tendon. The established constitutive model is of great significance to the prediction, repair and replacement of patellar tendon injury. In addition, human patellar tendon has a higher elastin content, so the results of this study can provide supporting information on the natural properties of tendon elastin degradation and guide the development of artificial patellar tendon biomaterials.
Collapse
Affiliation(s)
- Xiaoyun Liu
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yuping Deng
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, China
- Department of Orthopedics and Traumatology, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Zeyu Liang
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Dan Qiao
- Department of Pathology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, Zhejiang, China
| | - Wentian Zhang
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- The School of Basic Medical Sciences, Fujian Medical University, Fujian, China
| | - Mian Wang
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, China
- Department of Orthopaedics, Pingshan General Hospital of Southern Medical University, Shenzhen, China
| | - Feifei Li
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Jiannan Liu
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yaobing Wu
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Guangxin Chen
- Medical Image College, Mudanjiang Medical University, Mudanjiang, Heilongjiang, China
| | - Yan Liu
- Department of Anatomy, Gannan Healthcare Vocational College, Ganzhou, China
| | - Wenchang Tan
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Jian Xing
- Medical Image College, Mudanjiang Medical University, Mudanjiang, Heilongjiang, China
| | - Wenhua Huang
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Department of Orthopedics and Traumatology, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
- Guangdong Medical Innovation Platform for Translation of 3D Printing Application, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Dongliang Zhao
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yanbing Li
- National Key Discipline of Human Anatomy, Guangdong Provincial Key Laboratory of Medical Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| |
Collapse
|
2
|
Chato-Astrain J, Roda O, Carriel V, Hita-Contreras F, Sánchez-Montesinos I, Alaminos M, Hernández-Cortés P. Histological characterization of the human scapholunate ligament. Microsc Res Tech 2024; 87:257-271. [PMID: 37767790 DOI: 10.1002/jemt.24428] [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: 01/12/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023]
Abstract
The scapholunate interosseous ligament (SLIL) plays a fundamental role in stabilizing the wrist bones, and its disruption is a frequent cause of wrist arthrosis and disfunction. Traditionally, this structure is considered to be a variety of fibrocartilaginous tissue and consists of three regions: dorsal, membranous and palmar. Despite its functional relevance, the exact composition of the human SLIL is not well understood. In the present work, we have analyzed the human SLIL and control tissues from the human hand using an array of histological, histochemical and immunohistochemical methods to characterize each region of this structure. Results reveal that the SLIL is heterogeneous, and each region can be subdivided in two zones that are histologically different to the other zones. Analysis of collagen and elastic fibers, and several proteoglycans, glycoproteins and glycosaminoglycans confirmed that the different regions can be subdivided in two zones that have their own structure and composition. In general, all parts of the SLIL resemble the histological structure of the control articular cartilage, especially the first part of the membranous region (zone M1). Cells showing a chondrocyte-like phenotype as determined by S100 were more abundant in M1, whereas the zone containing more CD73-positive stem cells was D2. These results confirm the heterogeneity of the human SLIL and could contribute to explain why certain zones of this structure are more prone to structural damage and why other zones have specific regeneration potential. RESEARCH HIGHLIGHTS: Application of an array of histological analysis methods allowed us to demonstrate that the human scapholunate ligament is heterogeneous and consists of at least six different regions sharing similarities with the human cartilage, ligament and other anatomical structures.
Collapse
Affiliation(s)
- Jesús Chato-Astrain
- Tissue Engineering Group, Department of Histology, Faculty of Medicine, University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
| | - Olga Roda
- Department of Human Anatomy and Embryology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Víctor Carriel
- Tissue Engineering Group, Department of Histology, Faculty of Medicine, University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
| | - Fidel Hita-Contreras
- Department of Health Sciences, Faculty of Health Sciences, University of Jaén, Jaén, Spain
| | - Indalecio Sánchez-Montesinos
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
- Department of Human Anatomy and Embryology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Miguel Alaminos
- Tissue Engineering Group, Department of Histology, Faculty of Medicine, University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
| | - Pedro Hernández-Cortés
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
- Department of Surgery and Surgical Specialties, Faculty of Medicine, University of Granada, Granada, Spain
- Division of Traumatology and Orthopedic Surgery, San Cecilio University Hospital, Granada, Spain
| |
Collapse
|
3
|
Loffet EA, Durel JF, Gao J, Kam R, Lim H, Nerurkar NL. Elastic fibers define embryonic tissue stiffness to enable buckling morphogenesis of the small intestine. Biomaterials 2023; 303:122405. [PMID: 38000151 PMCID: PMC10842730 DOI: 10.1016/j.biomaterials.2023.122405] [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: 07/24/2023] [Revised: 10/22/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023]
Abstract
During embryonic development, tissues must possess precise material properties to ensure that cell-generated forces give rise to the stereotyped morphologies of developing organs. However, the question of how material properties are established and regulated during development remains understudied. Here, we aim to address these broader questions through the study of intestinal looping, a process by which the initially straight intestinal tube buckles into loops, permitting ordered packing within the body cavity. Looping results from elongation of the tube against the constraint of an attached tissue, the dorsal mesentery, which is elastically stretched by the elongating tube to nearly triple its length. This elastic energy storage allows the mesentery to provide stable compressive forces that ultimately buckle the tube into loops. Beginning with a transcriptomic analysis of the mesentery, we identified widespread upregulation of extracellular matrix related genes during looping, including genes related to elastic fiber deposition. Combining molecular and mechanical analyses, we conclude that elastin confers tensile stiffness to the mesentery, enabling its mechanical role in organizing the developing small intestine. These results shed light on the role of elastin as a driver of morphogenesis that extends beyond its more established role in resisting cyclic deformation in adult tissues.
Collapse
Affiliation(s)
- Elise A Loffet
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - John F Durel
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Jenny Gao
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Richard Kam
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Hyunjee Lim
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Nandan L Nerurkar
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA.
| |
Collapse
|
4
|
Halvorsen S, Wang R, Zhang Y. Contribution of Elastic and Collagen Fibers to the Mechanical Behavior of Bovine Nuchal Ligament. Ann Biomed Eng 2023; 51:2204-2215. [PMID: 37284997 PMCID: PMC10528717 DOI: 10.1007/s10439-023-03254-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 05/16/2023] [Indexed: 06/08/2023]
Abstract
Ligamentum nuchae is a highly elastic tissue commonly used to study the structure and mechanics of elastin. This study combines imaging, mechanical testing, and constitutive modeling to examine the structural organization of elastic and collagen fibers and their contributions to the nonlinear stress-strain behavior of the tissue. Rectangular samples of bovine ligamentum nuchae cut in both longitudinal and transverse directions were tested in uniaxial tension. Purified elastin samples were also obtained and tested. It was observed that the stress-stretch response of purified elastin tissue follows a similar curve as the intact tissue initially, but the intact tissue shows a significant stiffening behavior for stretches above 1.29 with collagen engagement. Multiphoton and histology images confirm the elastin-dominated bulk of ligamentum nuchae interspersed with small bundles of collagen fibrils and sporadic collagen-rich regions with cellular components and ground substance. A transversely isotropic constitutive model that considers the longitudinal organization of elastic and collagen fibers was developed to describe the mechanical behavior of both intact and purified elastin tissue under uniaxial tension. These findings shed light on the unique structural and mechanical roles of elastic and collagen fibers in tissue mechanics and may aid in future use of ligamentum nuchae in tissue grafting.
Collapse
Affiliation(s)
- Samuel Halvorsen
- Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, MA, 02215, USA
| | - Ruizhi Wang
- Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, MA, 02215, USA
| | - Yanhang Zhang
- Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, MA, 02215, USA.
- Biomedical Engineering, Boston University, Boston, MA, USA.
- Division of Materials Science & Engineering, Boston University, Boston, MA, USA.
| |
Collapse
|
5
|
Serikawa M, Ambe K, Usami A. Histological observations of age-related changes in the epiglottis associated with decreased deglutition function in older adults. Anat Cell Biol 2023; 56:374-381. [PMID: 37258424 PMCID: PMC10520849 DOI: 10.5115/acb.23.081] [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: 03/22/2023] [Revised: 04/10/2023] [Accepted: 04/14/2023] [Indexed: 06/02/2023] Open
Abstract
Although the epiglottis plays a vital role in deglutition, histological studies of the epiglottis and surrounding ligaments associated with swallowing dysfunction are limited. Therefore, we performed histological observations to clarify age-related changes in the morphological characteristics of the epiglottis and surrounding structures. Tissue samples comprising the epiglottis and surrounding structures were collected from corpses that were both orally fed and tube-fed during their lifetimes. Following hematoxylin and eosin, Elastica Van Gieson, and immunohistochemical staining procedures, the chondrocytes, connective tissue, and glandular tissue were observed under the epiglottis epithelium, and intervening adipose tissue was observed in the surrounding area. Fatty degeneration of acinar cells was also observed in the glandular tissue, possibly because of aging. Bundles of elastic fibers were present around the vascular wall in the peri-epiglottic ligament, but some were reduced. Furthermore, large amounts of collagen fibers ran toward and through the cartilage, whereas the mesh-like elastic fibers stopped in front of the cartilage. Microfibrils considered to be oxytalan fibers, which are thinner and shorter than elastic fibers, were observed around the vascular wall and in the fiber bundles. Age-related changes included connective tissue fibrosis shown by the large amount of collagen fibers, atrophy of salivary glands, and an accompanying increase in adipose tissue. Regarding stretchability and elasticity, the elastic fibers may have an auxiliary function for laryngeal elevation during deglutition. This suggests that disuse atrophy of the laryngeal organs with or without oral intake might reduce the amount of elastic fiber in older adults.
Collapse
Affiliation(s)
- Masamitsu Serikawa
- Department of Morphological Biology, Ohu University School of Dentistry, Koriyama, Japan
| | - Kimiharu Ambe
- Department of Morphological Biology, Ohu University School of Dentistry, Koriyama, Japan
| | - Akinobu Usami
- Department of Morphological Biology, Ohu University School of Dentistry, Koriyama, Japan
| |
Collapse
|
6
|
Loffet EA, Durel JF, Kam R, Lim H, Nerurkar NL. ELASTIC FIBERS DEFINE EMBRYONIC TISSUE STIFFNESS TO ENABLE BUCKLING MORPHOGENESIS OF THE SMALL INTESTINE. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.18.549562. [PMID: 37502968 PMCID: PMC10370103 DOI: 10.1101/2023.07.18.549562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
During embryonic development, tissues must possess precise material properties to ensure that cell-generated forces give rise to the stereotyped morphologies of developing organs. However, the question of how material properties are established and regulated during development remains understudied. Here, we aim to address these broader questions through the study of intestinal looping, a process by which the initially straight intestinal tube buckles into loops, permitting ordered packing within the body cavity. Looping results from elongation of the tube against the constraint of an attached tissue, the dorsal mesentery, which is elastically stretched by the elongating tube to nearly triple its length. This elastic energy storage allows the mesentery to provide stable compressive forces that ultimately buckle the tube into loops. Beginning with a transcriptomic analysis of the mesentery, we identified widespread upregulation of extracellular matrix related genes during looping, including genes related to elastic fiber deposition. Combining molecular and mechanical analyses, we conclude that elastin confers tensile stiffness to the mesentery, enabling its mechanical role in organizing the developing small intestine. These results shed light on the role of elastin as a driver of morphogenesis that extends beyond its more established role in resisting cyclic deformation in adult tissues.
Collapse
Affiliation(s)
- Elise A. Loffet
- Department of Biomedical Engineering, Columbia University, New York NY 10027
| | - John F. Durel
- Department of Biomedical Engineering, Columbia University, New York NY 10027
| | - Richard Kam
- Department of Biomedical Engineering, Columbia University, New York NY 10027
| | - Hyunjee Lim
- Department of Biomedical Engineering, Columbia University, New York NY 10027
| | - Nandan L. Nerurkar
- Department of Biomedical Engineering, Columbia University, New York NY 10027
| |
Collapse
|
7
|
Yang F, Das D, Karunakaran K, Genin GM, Thomopoulos S, Chasiotis I. Nonlinear time-dependent mechanical behavior of mammalian collagen fibrils. Acta Biomater 2023; 163:63-77. [PMID: 35259515 PMCID: PMC9441475 DOI: 10.1016/j.actbio.2022.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 02/16/2022] [Accepted: 03/02/2022] [Indexed: 11/01/2022]
Abstract
The viscoelastic mechanical behavior of collagenous tissues has been studied extensively at the macroscale, yet a thorough quantitative understanding of the time-dependent mechanics of the basic building blocks of tissues, the collagen fibrils, is still missing. In order to address this knowledge gap, stress relaxation and creep tests at various stress (5-35 MPa) and strain (5-20%) levels were performed with individual collagen fibrils (average diameter of fully hydrated fibrils: 253 ± 21 nm) in phosphate buffered saline (PBS). The experimental results showed that the time-dependent mechanical behavior of fully hydrated individual collagen fibrils reconstituted from Type I calf skin collagen, is described by strain-dependent stress relaxation and stress-dependent creep functions in both the heel-toe and the linear regimes of deformation in monotonic stress-strain curves. The adaptive quasilinear viscoelastic (QLV) model, originally developed to capture the nonlinear viscoelastic response of collagenous tissues, provided a very good description of the nonlinear stress relaxation and creep behavior of the collagen fibrils. On the other hand, the nonlinear superposition (NSP) model fitted well the creep but not the stress relaxation data. The time constants and rates extracted from the adaptive QLV and the NSP models, respectively, pointed to a faster rate for stress relaxation than creep. This nonlinear viscoelastic behavior of individual collagen fibrils agrees with prior studies of macroscale collagenous tissues, thus demonstrating consistent time-dependent behavior across length scales and tissue hierarchies. STATEMENT OF SIGNIFICANCE: Pure stress relaxation and creep experiments were conducted for the first time with fully hydrated individual collagen fibrils. It is shown that collagen nanofibrils have a nonlinear time-dependent behavior which agrees with prior studies on macroscale collagenous tissues, thus demonstrating consistent time-dependent behavior across length scales and tissue hierarchies. This new insight into the non-linear viscoelastic behavior of the building blocks of mammalian collagenous tissues may serve as the foundation for improved macroscale tissue models that capture the mechanical behavior across length scales.
Collapse
Affiliation(s)
- Fan Yang
- Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Debashish Das
- Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Kathiresan Karunakaran
- Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Guy M Genin
- Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130, USA
| | - Stavros Thomopoulos
- Orthopedic Surgery, Biomedical Engineering, Columbia University, New York, NY 10032, USA
| | - Ioannis Chasiotis
- Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| |
Collapse
|
8
|
Trębacz H, Barzycka A. Mechanical Properties and Functions of Elastin: An Overview. Biomolecules 2023; 13:biom13030574. [PMID: 36979509 PMCID: PMC10046833 DOI: 10.3390/biom13030574] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/08/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Human tissues must be elastic, much like other materials that work under continuous loads without losing functionality. The elasticity of tissues is provided by elastin, a unique protein of the extracellular matrix (ECM) of mammals. Its function is to endow soft tissues with low stiffness, high and fully reversible extensibility, and efficient elastic-energy storage. Depending on the mechanical functions, the amount and distribution of elastin-rich elastic fibers vary between and within tissues and organs. The article presents a concise overview of the mechanical properties of elastin and its role in the elasticity of soft tissues. Both the occurrence of elastin and the relationship between its spatial arrangement and mechanical functions in a given tissue or organ are overviewed. As elastin in tissues occurs only in the form of elastic fibers, the current state of knowledge about their mechanical characteristics, as well as certain aspects of degradation of these fibers and their mechanical performance, is presented. The overview also outlines the latest understanding of the molecular basis of unique physical characteristics of elastin and, in particular, the origin of the driving force of elastic recoil after stretching.
Collapse
Affiliation(s)
- Hanna Trębacz
- Department of Biophysics, Medical University of Lublin, Al. Racławickie 1, 20-059 Lublin, Poland
| | - Angelika Barzycka
- Department of Biophysics, Medical University of Lublin, Al. Racławickie 1, 20-059 Lublin, Poland
| |
Collapse
|
9
|
Nesbitt DQ, Burruel DE, Henderson BS, Lujan TJ. Finite element modeling of meniscal tears using continuum damage mechanics and digital image correlation. Sci Rep 2023; 13:4039. [PMID: 36899069 PMCID: PMC10006193 DOI: 10.1038/s41598-023-29111-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/31/2023] [Indexed: 03/12/2023] Open
Abstract
Meniscal tears are a common, painful, and debilitating knee injury with limited treatment options. Computational models that predict meniscal tears may help advance injury prevention and repair, but first these models must be validated using experimental data. Here we simulated meniscal tears with finite element analysis using continuum damage mechanics (CDM) in a transversely isotropic hyperelastic material. Finite element models were built to recreate the coupon geometry and loading conditions of forty uniaxial tensile experiments of human meniscus that were pulled to failure either parallel or perpendicular to the preferred fiber orientation. Two damage criteria were evaluated for all experiments: von Mises stress and maximum normal Lagrange strain. After we successfully fit all models to experimental force-displacement curves (grip-to-grip), we compared model predicted strains in the tear region at ultimate tensile strength to the strains measured experimentally with digital image correlation (DIC). In general, the damage models underpredicted the strains measured in the tear region, but models using von Mises stress damage criterion had better overall predictions and more accurately simulated experimental tear patterns. For the first time, this study has used DIC to expose strengths and weaknesses of using CDM to model failure behavior in soft fibrous tissue.
Collapse
Affiliation(s)
- Derek Q Nesbitt
- Biomedical Engineering Doctoral Program, Boise State University, Boise, ID, USA
| | - Dylan E Burruel
- Department of Mechanical and Biomedical Engineering, Boise State University, 1910 University Drive, Boise, ID, 83725-2085, USA
| | - Bradley S Henderson
- Department of Mechanical and Biomedical Engineering, Boise State University, 1910 University Drive, Boise, ID, 83725-2085, USA
| | - Trevor J Lujan
- Department of Mechanical and Biomedical Engineering, Boise State University, 1910 University Drive, Boise, ID, 83725-2085, USA.
| |
Collapse
|
10
|
Allan AN, Zitnay JL, Maas SA, Weiss JA. Development of a continuum damage model to Predict accumulation of sub-failure damage in tendons. J Mech Behav Biomed Mater 2022; 135:105342. [DOI: 10.1016/j.jmbbm.2022.105342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 05/18/2022] [Accepted: 06/26/2022] [Indexed: 11/17/2022]
|
11
|
Eekhoff JD, Abraham JA, Schott HR, Solon LF, Ulloa GE, Zellers JA, Cannon PC, Lake SP. Fascicular elastin within tendon contributes to the magnitude and modulus gradient of the elastic stress response across tendon type and species. Acta Biomater 2022; 163:91-105. [PMID: 35306182 DOI: 10.1016/j.actbio.2022.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 11/19/2022]
Abstract
Elastin, the main component of elastic fibers, has been demonstrated to significantly influence tendon mechanics using both elastin degradation studies and elastinopathic mouse models. However, it remains unclear how prior results differ between species and functionally distinct tendons and, in particular, how results translate to human tendon. Differences in function between fascicular and interfascicular elastin are also yet to be fully elucidated. Therefore, this study evaluated the quantity, structure, and mechanical contribution of elastin in functionally distinct tendons across species. Tendons with an energy-storing function had slightly more elastin content than tendons with a positional function, and human tendon had at least twice the elastin content of other species. While distinctions in the organization of elastic fibers between fascicles and the interfascicular matrix were observed, differences in structural arrangement of the elastin network between species and tendon type were limited. Mechanical testing paired with enzyme-induced elastin degradation was used to evaluate the contribution of elastin to tendon mechanics. Across all tendons, elastin degradation affected the elastic stress response by decreasing stress values while increasing the modulus gradient of the stress-strain curve. Only the contributions of elastin to viscoelastic properties varied between tendon type and species, with human tendon and energy-storing tendon being more affected. These data suggest that fascicular elastic fibers contribute to the tensile mechanical response of tendon, likely by regulating collagen engagement under load. Results add to prior findings and provide evidence for a more mechanistic understanding of the role of elastic fibers in tendon. STATEMENT OF SIGNIFICANCE: Elastin has previously been shown to influence the mechanical properties of tendon, and degraded or abnormal elastin networks caused by aging or disease may contribute to pain and an increased risk of injury. However, prior work has not fully determined how elastin contributes differently to tendons with varying functional demands, as well as within distinct regions of tendon. This study determined the effects of elastin degradation on the tensile elastic and viscoelastic responses of tendons with varying functional demands, hierarchical structures, and elastin content. Moreover, volumetric imaging and protein quantification were used to thoroughly characterize the elastin network in each distinct tendon. The results presented herein can inform tendon-specific strategies to maintain or restore native properties in elastin-degraded tissue.
Collapse
Affiliation(s)
- Jeremy D Eekhoff
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, MSC: 1185-208-125, St. Louis, MO 63130, United States
| | - James A Abraham
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States
| | - Hayden R Schott
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States
| | - Lorenzo F Solon
- Department of Biology, Washington University in St. Louis, United States
| | - Gabriella E Ulloa
- Department of Mechanical Engineering, Massachusetts Institute of Technology, United States
| | - Jennifer A Zellers
- Department of Physical Therapy, Washington University in St. Louis School of Medicine, United States
| | - Paul C Cannon
- Department of Mathematics, Brigham Young University - Idaho, United States
| | - Spencer P Lake
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, MSC: 1185-208-125, St. Louis, MO 63130, United States; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, United States; Department of Orthopaedic Surgery, Washington University in St. Louis School of Medicine, , United States.
| |
Collapse
|
12
|
Acuna A, Jimenez JM, Deneke N, Rothenberger SM, Libring S, Solorio L, Rayz VL, Davis CS, Calve S. Design and validation of a modular micro-robotic system for the mechanical characterization of soft tissues. Acta Biomater 2021; 134:466-476. [PMID: 34303012 PMCID: PMC8542608 DOI: 10.1016/j.actbio.2021.07.035] [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: 01/07/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 10/20/2022]
Abstract
The mechanical properties of tissues are critical design parameters for biomaterials and regenerative therapies seeking to restore functionality after disease or injury. Characterizing the mechanical properties of native tissues and extracellular matrix throughout embryonic development helps us understand the microenvironments that promote growth and remodeling, activities critical for biomaterials to support. The mechanical characterization of small, soft materials like the embryonic tissues of the mouse, an established mammalian model for development, is challenging due to difficulties in handling minute geometries and resolving forces of low magnitude. While uniaxial tensile testing is the physiologically relevant modality to characterize tissues that are loaded in tension in vivo, there are no commercially available instruments that can simultaneously measure sufficiently low tensile force magnitudes, directly measure sample deformation, keep samples hydrated throughout testing, and effectively grip minute geometries to test small tissues. To address this gap, we developed a micromanipulator and spring system that can mechanically characterize small, soft materials under tension. We demonstrate the capability of this system to measure the force contribution of soft materials, silicone, fibronectin sheets, and fibrin gels with a 5 nN - 50 µN force resolution and perform a variety of mechanical tests. Additionally, we investigated murine embryonic tendon mechanics, demonstrating the instrument can measure differences in mechanics of small, soft tissues as a function of developmental stage. This system can be further utilized to mechanically characterize soft biomaterials and small tissues and provide physiologically relevant parameters for designing scaffolds that seek to emulate native tissue mechanics. STATEMENT OF SIGNIFICANCE: The mechanical properties of cellular microenvironments are critical parameters that contribute to the modulation of tissue growth and remodeling. The field of tissue engineering endeavors to recapitulate these microenvironments in order to construct tissues de novo. Therefore, it is crucial to uncover the mechanical properties of the cellular microenvironment during tissue formation. Here, we present a system capable of acquiring microscale forces and optically measuring sample deformation to calculate the stress-strain response of soft, embryonic tissues under tension, and easily adaptable to accommodate biomaterials of various sizes and stiffnesses. Altogether, this modular system enables researchers to probe the unknown mechanical properties of soft tissues throughout development to inform the engineering of physiologically relevant microenvironments.
Collapse
Affiliation(s)
- Andrea Acuna
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States
| | - Julian M Jimenez
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States
| | - Naomi Deneke
- School of Materials Engineering, Purdue University, Neil Armstrong Hall of Engineering, 701 West Stadium Avenue, West Lafayette, IN 47907, United States
| | - Sean M Rothenberger
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States
| | - Sarah Libring
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States
| | - Luis Solorio
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States; Purdue Center for Cancer Research, Purdue University, 201 South Street, West Lafayette, IN 47906, United States
| | - Vitaliy L Rayz
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States
| | - Chelsea S Davis
- School of Materials Engineering, Purdue University, Neil Armstrong Hall of Engineering, 701 West Stadium Avenue, West Lafayette, IN 47907, United States
| | - Sarah Calve
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States; Paul M. Rady Department of Mechanical Engineering, University of Colorado - Boulder, 1111 Engineering Center, 427 UCB, Boulder, CO 80309, United States.
| |
Collapse
|
13
|
Xie WQ, He M, He YQ, Yu DJ, Jin HF, Yu F, Li YS. The effects of posterior cruciate ligament rupture on the biomechanical and histological characteristics of the medial collateral ligament: an animal study. J Orthop Surg Res 2021; 16:330. [PMID: 34020667 PMCID: PMC8139104 DOI: 10.1186/s13018-021-02443-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 04/22/2021] [Indexed: 12/23/2022] Open
Abstract
Background To investigate the effect of complete rupture of the posterior cruciate ligament (PCL) on the biomechanics and histology of the medial collateral ligament (MCL). Materials and methods Seventy-two male rabbits were randomly divided into two groups: the ruptured group was treated with complete PCL amputation, while the intact group was only subjected to PCL exposure without amputation. Eighteen rabbits were randomly sacrificed at 8, 16, 24, and 40 weeks after the operation, and their specimens were processed for mechanical tensile testing, nano-indentation experiments, hematoxylin-eosin (HE) staining, and picrosirius-polarization staining. Results There was no significant difference in the length and maximum displacement of the MCL between the ruptured group and the intact group at each time point. The maximum load of the ruptured group was significantly smaller than that of the intact group at 40 W. The elastic modulus and micro-hardness of the ruptured group increased significantly at 24 W and decreased significantly at 40 W. At 16 W and 24 W after PCL rupture, the number of type I collagen fibers and type III collagen fibers in the MCL of the ruptured group was significantly increased compared with that of the intact group. While the type I collagen fibers of the ruptured group were significantly decreased compared with the intact group at 40 W, there was no significant difference in type III collagen fibers between the ruptured group and the intact group. Conclusion PCL rupture has no significant effect on the mechanical and histological properties of MCL in a short period of time under physiological loading, but the histological and mechanical properties of MCL decrease with time.
Collapse
Affiliation(s)
- Wen-Qing Xie
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Miao He
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Yu-Qiong He
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Deng-Jie Yu
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Hong-Fu Jin
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Fang Yu
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China.
| | - Yu-Sheng Li
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China.
| |
Collapse
|
14
|
Investigation of fibrillin microfibrils in the canine cruciate ligament in dogs with different predispositions to ligament rupture. Res Vet Sci 2020; 133:53-58. [PMID: 32937286 DOI: 10.1016/j.rvsc.2020.09.006] [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: 02/27/2020] [Revised: 06/03/2020] [Accepted: 09/08/2020] [Indexed: 11/20/2022]
Abstract
Cranial cruciate ligament disease (CCLD) is the most common cause of pelvic limb lameness in dogs but its precise aetiopathogenesis is uncertain. Fibrillin microfibrils (FM) are complex macro-molecular assemblies found in many tissues including ligaments, where they are thought to play an important mechanical role. We hypothesised that FM ultrastructural variation correlates with the differing predisposition of canine breeds to CCLD. Non-diseased cranial and caudal cruciate ligaments (CCLs and CaCLs) were obtained from Greyhound (GH) and Staffordshire Bull Terrier (SBT) cadavers. Fibrillin microfibrils were extracted from the ligaments by bacterial collagenase digestion, purified by size-exclusion chromatography and subsequently visualized by atomic force microscopy (AFM). With AFM, FMs have a characteristic beads-on-a-string appearance. For each FM, periodicity (bead-bead distance) and length (number of beads/FM) was measured. Fibrillin microfibril length was found to be similar for GH and SBT, with non-significant inter-breed and inter-ligament differences. Fibrillin microfibril periodicity varied when comparing GH and SBT for CCL (GH 60.2 ± 1.4 nm; SBT 56.2 ± 0.8 nm) and CaCL (GH 55.5 ± 1.6 nm; SBT 61.2 ± 1.2 nm). A significant difference was found in the periodicity distribution when comparing CCL for both breeds (P < 0.00001), further, intra-breed differences in CCL vs CaCL were statistically significant within both breeds (P < 0.00001). The breed at low risk of CCLD exhibited a periodicity profile which may be suggestive of a repair and remodelling within the CCL.
Collapse
|