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Soshnikova YM, Shekhter AB, Baum OI, Shcherbakov EM, Omelchenko AI, Lunin VV, Sobol EN. Laser radiation effect on chondrocytes and intercellular matrix of costal and articular cartilage impregnated with magnetite nanoparticles. Lasers Surg Med 2015; 47:243-51. [PMID: 25689939 DOI: 10.1002/lsm.22331] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND OBJECTIVE Magnetic nanoparticles with the ability to absorb laser radiation are the perspective agents for the early diagnostics and laser therapy of degenerative cartilage. The effect of starch stabilized magnetite nanoparticles (SSNPs) on the cartilage structure components has never been studied before. The aim of the work is to establish the Erbium:glass laser effect on costal and articular cartilage impregnated with SSNPs. MATERIALS AND METHODS Porcine articular and costal cartilage disks (2.0 mm in diameter and 1.5-2 mm in thickness) were impregnated with SSNPs and irradiated using a 1.56 μm laser in therapeutic laser setting. The one sample group underwent the second irradiation after the SSNPs impregnation. The samples were analyzed by the means of histology, histochemistry and transmission electron microscopy (TEM) to reveal the alterations of cells, glycosaminoglycans and collagen network. RESULTS The irradiated cartilage demonstrates the higher content of cell alterations than the intact one due to the heat and mechanical affection in the course of laser irradiation. However the alterations are localized at the areas near the irradiated surfaces and not dramatic. The impregnation of SSNPs does not cause any additional cell alterations. For both costal and articular cartilage the matrix alterations of irradiated samples are not critical: there is the slight decrease in acid proteoglycan content at the irradiated areas while the collagen network is not altered. Distribution and localization of impregnated SSNPs is described: agglomerates of 150-230 nm are observed located at the borders between matrix and cell lacunas of articular cartilage; SSNPs of 15-45 nm are found in the collagen network of costal cartilage. CONCLUSIONS It was shown that SSNPs do not appreciably affect the structural components of both articular and costal cartilage and can be safely used for the laser diagnostics and therapy. The area of structural alterations is diffuse and local as the result of the mechanical and heat effect of laser impact. SSNPs reveal the areas of the structural alterations of cartilage matrix and give information about the size of the pores and defects.
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Affiliation(s)
- Yulia M Soshnikova
- Institute on Laser and Information Technologies, Russian Academy of Sciences, Troitsk, 142190, Russia; Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia
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202
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Li S, Glynne-Jones P, Andriotis OG, Ching KY, Jonnalagadda US, Oreffo ROC, Hill M, Tare RS. Application of an acoustofluidic perfusion bioreactor for cartilage tissue engineering. LAB ON A CHIP 2014; 14:4475-85. [PMID: 25272195 PMCID: PMC4227593 DOI: 10.1039/c4lc00956h] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 09/24/2014] [Indexed: 05/20/2023]
Abstract
Cartilage grafts generated using conventional static tissue engineering strategies are characterised by low cell viability, suboptimal hyaline cartilage formation and, critically, inferior mechanical competency, which limit their application for resurfacing articular cartilage defects. To address the limitations of conventional static cartilage bioengineering strategies and generate robust, scaffold-free neocartilage grafts of human articular chondrocytes, the present study utilised custom-built microfluidic perfusion bioreactors with integrated ultrasound standing wave traps. The system employed sweeping acoustic drive frequencies over the range of 890 to 910 kHz and continuous perfusion of the chondrogenic culture medium at a low-shear flow rate to promote the generation of three-dimensional agglomerates of human articular chondrocytes, and enhance cartilage formation by cells of the agglomerates via improved mechanical stimulation and mass transfer rates. Histological examination and assessment of micromechanical properties using indentation-type atomic force microscopy confirmed that the neocartilage grafts were analogous to native hyaline cartilage. Furthermore, in the ex vivo organ culture partial thickness cartilage defect model, implantation of the neocartilage grafts into defects for 16 weeks resulted in the formation of hyaline cartilage-like repair tissue that adhered to the host cartilage and contributed to significant improvements to the tissue architecture within the defects, compared to the empty defects. The study has demonstrated the first successful application of the acoustofluidic perfusion bioreactors to bioengineer scaffold-free neocartilage grafts of human articular chondrocytes that have the potential for subsequent use in second generation autologous chondrocyte implantation procedures for the repair of partial thickness cartilage defects.
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Affiliation(s)
- Siwei Li
- Centre for Human Development , Stem Cells and Regeneration , Faculty of Medicine , University of Southampton , Southampton SO16 6YD , UK . ; Fax: +44 2381 204221 ; Tel: +44 (0)2381 205257
| | - Peter Glynne-Jones
- Engineering Sciences , Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK
| | - Orestis G. Andriotis
- Institute of Lightweight Design and Structural Biomechanics , Vienna University of Technology , Gusshausstrasse 27-29 A-1040 , Vienna , Austria
| | - Kuan Y. Ching
- nCATS , Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK
| | - Umesh S. Jonnalagadda
- Engineering Sciences , Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK
| | - Richard O. C. Oreffo
- Centre for Human Development , Stem Cells and Regeneration , Faculty of Medicine , University of Southampton , Southampton SO16 6YD , UK . ; Fax: +44 2381 204221 ; Tel: +44 (0)2381 205257
| | - Martyn Hill
- Engineering Sciences , Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK
| | - Rahul S. Tare
- Centre for Human Development , Stem Cells and Regeneration , Faculty of Medicine , University of Southampton , Southampton SO16 6YD , UK . ; Fax: +44 2381 204221 ; Tel: +44 (0)2381 205257
- Engineering Sciences , Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK
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203
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Park JY, Duong CT, Sharma AR, Son KM, Thompson MS, Park S, Chang JD, Nam JS, Park S, Lee SS. Effects of hyaluronic acid and γ-globulin concentrations on the frictional response of human osteoarthritic articular cartilage. PLoS One 2014; 9:e112684. [PMID: 25426992 PMCID: PMC4245191 DOI: 10.1371/journal.pone.0112684] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Accepted: 10/09/2014] [Indexed: 11/19/2022] Open
Abstract
Synovial fluid plays an important role in lubricating synovial joints. Its main constituents are hyaluronic acid (HA) and γ-globulin, acting as boundary lubricants for articular cartilage. The aim of the study was to demonstrate the concentration-dependent effect of HA and γ-globulin on the boundary-lubricating ability of human osteoarthritis (OA) cartilage. Normal, early and advance stage articular cartilage samples were obtained from human femoral heads and in presence of either HA or γ-globulin, cartilage frictional coefficient (µ) was measured by atomic force microscopy (AFM). In advanced stage OA, the cartilage superficial layer was observed to be completely removed and the damaged cartilage surface showed a higher µ value (∼ 0.409) than the normal cartilage surface (∼ 0.119) in PBS. Adsorbed HA and γ-globulin molecules significantly improved the frictional behavior of advanced OA cartilage, while they were ineffective for normal and early OA cartilage. In advanced-stage OA, the concentration-dependent frictional response of articular cartilage was observed with γ-globulin, but not with HA. Our result suggested that HA and γ-globulin may play a significant role in improving frictional behavior of advanced OA cartilage. During early-stage OA, though HA and γ-globulin had no effect on improving frictional behavior of cartilage, however, they might contribute to disease modifying effects of synovial fluid as observed in clinical settings.
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Affiliation(s)
- Jae-Yong Park
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
| | - Cong-Truyen Duong
- School of Mechanical Engineering, Pusan National University, Busan, Republic of Korea
- Mechanical Engineering Department, Industrial University of Ho Chi Minh City, Ho Chi Minh, Vietnam
| | - Ashish Ranjan Sharma
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
| | - Kyeong-Min Son
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
| | - Mark S. Thompson
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Sungchan Park
- Department of Urology, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Jun-Dong Chang
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
| | - Ju-Suk Nam
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
| | - Seonghun Park
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
- School of Mechanical Engineering, Pusan National University, Busan, Republic of Korea
- * E-mail: (SP); (SSL)
| | - Sang-Soo Lee
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
- * E-mail: (SP); (SSL)
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204
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Nia HT, Gauci SJ, Azadi M, Hung HH, Frank E, Fosang AJ, Ortiz C, Grodzinsky AJ. High-bandwidth AFM-based rheology is a sensitive indicator of early cartilage aggrecan degradation relevant to mouse models of osteoarthritis. J Biomech 2014; 48:162-5. [PMID: 25435386 DOI: 10.1016/j.jbiomech.2014.11.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/07/2014] [Accepted: 11/08/2014] [Indexed: 11/25/2022]
Abstract
Murine models of osteoarthritis (OA) and post-traumatic OA have been widely used to study the development and progression of these diseases using genetically engineered mouse strains along with surgical or biochemical interventions. However, due to the small size and thickness of murine cartilage, the relationship between mechanical properties, molecular structure and cartilage composition has not been well studied. We adapted a recently developed AFM-based nano-rheology system to probe the dynamic nanomechanical properties of murine cartilage over a wide frequency range of 1 Hz to 10 kHz, and studied the role of glycosaminoglycan (GAG) on the dynamic modulus and poroelastic properties of murine femoral cartilage. We showed that poroelastic properties, highlighting fluid-solid interactions, are more sensitive indicators of loss of mechanical function compared to equilibrium properties in which fluid flow is negligible. These fluid-flow-dependent properties include the hydraulic permeability (an indicator of the resistance of matrix to fluid flow) and the high frequency modulus, obtained at high rates of loading relevant to jumping and impact injury in vivo. Utilizing a fibril-reinforced finite element model, we estimated the poroelastic properties of mouse cartilage over a wide range of loading rates for the first time, and show that the hydraulic permeability increased by a factor ~16 from knormal=7.80×10(-16)±1.3×10(-16) m(4)/N s to kGAG-depleted=1.26×10(-14)±6.73×10(-15) m(4)/N s after GAG depletion. The high-frequency modulus, which is related to fluid pressurization and the fibrillar network, decreased significantly after GAG depletion. In contrast, the equilibrium modulus, which is fluid-flow independent, did not show a statistically significant alteration following GAG depletion.
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Affiliation(s)
- Hadi T Nia
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Stephanie J Gauci
- University of Melbourne, Department of Paediatrics & Murdoch Children's Research Institute, Royal Childrens Hospital, Parkville, VIC, Australia
| | - Mojtaba Azadi
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Han-Hwa Hung
- Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Eliot Frank
- Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Amanda J Fosang
- University of Melbourne, Department of Paediatrics & Murdoch Children's Research Institute, Royal Childrens Hospital, Parkville, VIC, Australia
| | - Christine Ortiz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Alan J Grodzinsky
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States; Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States.
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205
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Subbiah R, Du P, Van SY, Suhaeri M, Hwang MP, Lee K, Park K. Fibronectin-tethered graphene oxide as an artificial matrix for osteogenesis. Biomed Mater 2014; 9:065003. [DOI: 10.1088/1748-6041/9/6/065003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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206
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Lu P, Yao S, Cai J, Yang PH. Synthesis and synergetic anti-tumor activity evaluation of dihydroartemisinin-organogermanium(IV) compound. Bioorg Med Chem Lett 2014; 24:5294-7. [PMID: 25304899 DOI: 10.1016/j.bmcl.2014.09.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/28/2014] [Accepted: 09/17/2014] [Indexed: 10/24/2022]
Abstract
Dihydroartemisinin (DHA), a semi-synthetic derivative of the herb artemisinin, has shown commendable bioactivity. In this paper, a novel dihydroartemisinin-organogermanium (DHA-Ge) compound was synthesized, characterized and its potential anti-tumor activity was evaluated by various methods. MTT results demonstrated that DHA-Ge could effectively inhibit the proliferation of HepG2 cells and showed their dose-dependent properties. The IC50 value of inhibition effect on HepG2 cells of DHA-Ge was 10.23 μg/ml which was lower than 39.44 μg/ml of DHA. Flow cytometric results suggested that DHA-Ge could induce apoptosis of HepG2 cells and the apoptosis rate was 20.26% after 24h treatment with 56.8 μg/ml DHA-Ge concentration. Atomic force microscopy images showed that HepG2 cells were collapsed and the cell nucleus were fragmented after 24h treatment. All these results together showed that the DHA-Ge possessed desirable synergetic enhanced anti-tumor effects and could be developed as a suitable tumor therapeutic agent.
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Affiliation(s)
- Peng Lu
- Department of Chemistry, Jinan University, Guangzhou 510632, China
| | - Shuguang Yao
- Department of Chemistry, Jinan University, Guangzhou 510632, China
| | - Jiye Cai
- Department of Chemistry, Jinan University, Guangzhou 510632, China
| | - Pei-hui Yang
- Department of Chemistry, Jinan University, Guangzhou 510632, China.
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207
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Huang X, He J, Liu M, Zhou C. The influence of aminophylline on the nanostructure and nanomechanics of T lymphocytes: an AFM study. NANOSCALE RESEARCH LETTERS 2014; 9:518. [PMID: 25258618 PMCID: PMC4174535 DOI: 10.1186/1556-276x-9-518] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 09/05/2014] [Indexed: 06/03/2023]
Abstract
Although much progress has been made in the illustration of the mechanism of aminophylline (AM) treating asthma, there is no data about its effect on the nanostructure and nanomechanics of T lymphocytes. Here, we presented atomic force spectroscopy (AFM)-based investigations at the nanoscale level to address the above fundamental biophysical questions. As increasing AM treatment time, T lymphocytes' volume nearly double increased and then decreased. The changes of nanostructural features of the cell membrane, i.e., mean height of particles, root-mean-square roughness (Rq), crack and fragment appearance, increased with AM treatment time. T lymphocytes were completely destroyed with 96-h treatment, and they existed in the form of small fragments. Analysis of force-distance curves showed that the adhesion force of cell surface decreased significantly with the increase of AM treatment time, while the cell stiffness increased firstly and then decreased. These changes were closely correlated to the characteristics and process of cell oncosis. In total, these quantitative and qualitative changes of T lymphocytes' structure and nanomechanical properties suggested that AM could induce T lymphocyte oncosis to exert anti-inflammatory effects for treating asthma. These findings provide new insights into the T lymphocyte oncosis and the anti-inflammatory mechanism and immune regulation actions of AM.
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Affiliation(s)
- Xun Huang
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510630, China
- Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510630, China
| | - Jiexiang He
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510630, China
- Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510630, China
| | - Mingxian Liu
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510630, China
- Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510630, China
| | - Changren Zhou
- Department of Materials Science and Engineering, Jinan University, Guangzhou 510630, China
- Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510630, China
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208
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Berteau JP, Oyen M, Shefelbine S. In vitrocharacterisation of the elasticity and the permeability of the mouse cartilage during growth using microindentation. Comput Methods Biomech Biomed Engin 2014; 17 Suppl 1:68-9. [DOI: 10.1080/10255842.2014.931129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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209
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Leung VY, Aladin DM, Lv F, Tam V, Sun Y, Lau RY, Hung SC, Ngan AH, Tang B, Lim CT, Wu EX, Luk KD, Lu WW, Masuda K, Chan D, Cheung KM. Mesenchymal Stem Cells Reduce Intervertebral Disc Fibrosis and Facilitate Repair. Stem Cells 2014; 32:2164-77. [DOI: 10.1002/stem.1717] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 03/01/2014] [Accepted: 03/20/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Victor Y.L. Leung
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Department of Biochemistry; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Centre for Reproduction, Development, and Growth; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Darwesh M.K. Aladin
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Mechanobiology Institute; National University of Singapore; Singapore
| | - Fengjuan Lv
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Vivian Tam
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Yi Sun
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Roy Y.C. Lau
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Siu-Chun Hung
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Alfonso H.W. Ngan
- Department of Mechanical Engineering; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Bin Tang
- Department of Micro-nano Materials and Devices; South University of Science and Technology of China; Guangzhou People's Republic of China
| | - Chwee Teck Lim
- Mechanobiology Institute; National University of Singapore; Singapore
- Department of Bioengineering; National University of Singapore; Singapore
- Department of Mechanical Engineering; National University of Singapore; Singapore
| | - Ed X. Wu
- Department of Electrical & Electronic Engineering; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Keith D.K. Luk
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - William W. Lu
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Koichi Masuda
- Department of Orthopaedic Surgery; University of California; San Diego California USA
| | - Danny Chan
- Department of Biochemistry; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Centre for Reproduction, Development, and Growth; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Kenneth M.C. Cheung
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Centre for Reproduction, Development, and Growth; The University of Hong Kong; Hong Kong SAR People's Republic of China
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210
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Nanomechanical assessment of human and murine collagen fibrils via atomic force microscopy cantilever-based nanoindentation. J Mech Behav Biomed Mater 2014; 39:9-26. [PMID: 25081997 DOI: 10.1016/j.jmbbm.2014.06.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 06/18/2014] [Accepted: 06/24/2014] [Indexed: 01/22/2023]
Abstract
The nanomechanical assessment of collagen fibrils via atomic force microscopy (AFM) is of increasing interest within the biomedical research community. In contrast to conventional nanoindentation there exists no common standard for conducting experiments and analysis of data. Currently used analysis approaches vary between studies and validation of quantitative results is usually not performed, which makes comparison of data from different studies difficult. Also there are no recommendations with regards to the maximum indentation depth that should not be exceeded to avoid substrate effects. Here we present a methodology and analysis approach for AFM cantilever-based nanoindentation experiments that allows efficient use of captured data and relying on a reference sample for determination of tip shape. Further we show experimental evidence that maximum indentation depth on collagen fibrils should be lower than 10-15% of the height of the fibril to avoid substrate effects and we show comparisons between our and other approaches used in previous works. While our analysis approach yields similar values for indentation modulus compared to the Oliver-Pharr method we found that Hertzian analysis yielded significantly lower values. Applying our approach we successfully and efficiently indented collagen fibrils from human bronchi, which were about 30 nm in size, considerably smaller compared to collagen fibrils obtained from murine tail-tendon. In addition, derived mechanical parameters of collagen fibrils are in agreement with data previously published. To establish a quantitative validation we compared indentation results from conventional and AFM cantilever-based nanoindentation on polymeric samples with known mechanical properties. Importantly we can show that our approach yields similar results when compared to conventional nanoindentation on polymer samples. Introducing an approach that is reliable, efficient and taking into account the AFM tip shape, we anticipate that the present work may act as a guideline for conducting AFM cantilever-based nanoindentation of collagen fibrils. This may aid understanding of collagen-related diseases such as asthma, lung fibrosis or bone disease with potential alterations of collagen fibril mechanics.
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211
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Batista MA, Nia HT, Önnerfjord P, Cox KA, Ortiz C, Grodzinsky AJ, Heinegård D, Han L. Nanomechanical phenotype of chondroadherin-null murine articular cartilage. Matrix Biol 2014; 38:84-90. [PMID: 24892719 PMCID: PMC6698058 DOI: 10.1016/j.matbio.2014.05.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/23/2014] [Accepted: 05/23/2014] [Indexed: 11/18/2022]
Abstract
Chondroadherin (CHAD), a class IV small leucine rich proteoglycan/protein (SLRP), was hypothesized to play important roles in regulating chondrocyte signaling and cartilage homeostasis. However, its roles in cartilage development and function are not well understood, and no major osteoarthritis-like phenotype was found in the murine model with CHAD genetically deleted (CHAD−/−). In this study, we used atomic force microscopy (AFM)-based nanoindentation to quantify the effects of CHAD deletion on changes in the biomechanical function of murine cartilage. In comparison to wild-type (WT) mice, CHAD-deletion resulted in a significant≈70–80% reduction in the indentation modulus, Eind, of the superficial zone knee cartilage of 11 weeks, 4 months and 1 year old animals. This mechanical phenotype correlates well with observed increases in the heterogeneity collagen fibril diameters in the surface zone. The results suggest that CHAD mainly plays a major role in regulating the formation of the collagen fibrillar network during the early skeletal development. In contrast, CHAD-deletion had no appreciable effects on the indentation mechanics of middle/deep zone cartilage, likely due to the dominating role of aggrecan in the middle/deep zone. The presence of significant rate dependence of the indentation stiffness in both WT and CHAD−/− knee cartilage suggested the importance of both fluid flow induced poroelasticity and intrinsic viscoelasticity in murine cartilage biomechanical properties. Furthermore, the marked differences in the nanomechanical behavior of WT versus CHAD−/− cartilage contrasted sharply with the relative absence of overt differences in histological appearance. These observations highlight the sensitivity of nanomechanical tools in evaluating structural and mechanical phenotypes in transgenic mice.
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Affiliation(s)
- Michael A Batista
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Hadi T Nia
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Patrik Önnerfjord
- Department of Clinical Sciences, Lund University, 22184 Lund, Sweden
| | - Karen A Cox
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, United States
| | - Christine Ortiz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Alan J Grodzinsky
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Dick Heinegård
- Department of Clinical Sciences, Lund University, 22184 Lund, Sweden
| | - Lin Han
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States.
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212
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Nanomechanical properties of multi-block copolymer microspheres for drug delivery applications. J Mech Behav Biomed Mater 2014; 34:313-9. [DOI: 10.1016/j.jmbbm.2014.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/28/2014] [Accepted: 03/09/2014] [Indexed: 12/19/2022]
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213
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Dague E, Genet G, Lachaize V, Guilbeau-Frugier C, Fauconnier J, Mias C, Payré B, Chopinet L, Alsteens D, Kasas S, Severac C, Thireau J, Heymes C, Honton B, Lacampagne A, Pathak A, Sénard JM, Galés C. Atomic force and electron microscopic-based study of sarcolemmal surface of living cardiomyocytes unveils unexpected mitochondrial shift in heart failure. J Mol Cell Cardiol 2014; 74:162-72. [PMID: 24839910 DOI: 10.1016/j.yjmcc.2014.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/07/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
Abstract
Loss of T-tubules (TT), sarcolemmal invaginations of cardiomyocytes (CMs), was recently identified as a general heart failure (HF) hallmark. However, whether TT per se or the overall sarcolemma is altered during HF process is still unknown. In this study, we directly examined sarcolemmal surface topography and physical properties using Atomic Force Microscopy (AFM) in living CMs from healthy and failing mice hearts. We confirmed the presence of highly organized crests and hollows along myofilaments in isolated healthy CMs. Sarcolemma topography was tightly correlated with elasticity, with crests stiffer than hollows and related to the presence of few packed subsarcolemmal mitochondria (SSM) as evidenced by electron microscopy. Three days after myocardial infarction (MI), CMs already exhibit an overall sarcolemma disorganization with general loss of crests topography thus becoming smooth and correlating with a decreased elasticity while interfibrillar mitochondria (IFM), myofilaments alignment and TT network were unaltered. End-stage post-ischemic condition (15days post-MI) exacerbates overall sarcolemma disorganization with, in addition to general loss of crest/hollow periodicity, a significant increase of cell surface stiffness. Strikingly, electron microscopy revealed the total depletion of SSM while some IFM heaps could be visualized beneath the membrane. Accordingly, mitochondrial Ca(2+) studies showed a heterogeneous pattern between SSM and IFM in healthy CMs which disappeared in HF. In vitro, formamide-induced sarcolemmal stress on healthy CMs phenocopied post-ischemic kinetics abnormalities and revealed initial SSM death and crest/hollow disorganization followed by IFM later disarray which moved toward the cell surface and structured heaps correlating with TT loss. This study demonstrates that the loss of crest/hollow organization of CM surface in HF occurs early and precedes disruption of the TT network. It also highlights a general stiffness increased of the CM surface most likely related to atypical IFM heaps while SSM died during HF process. Overall, these results indicate that initial sarcolemmal stress leading to SSM death could underlie subsequent TT disarray and HF setting.
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Affiliation(s)
- Etienne Dague
- CNRS, LAAS, F-31400 Toulouse, France; CNRS, ITAV-USR3505, Toulouse, France; Université de Toulouse, ITAV, LAAS, F-31400 Toulouse France.
| | - Gaël Genet
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | | | - Céline Guilbeau-Frugier
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France; Department of Histopathology, Centre Hospitalier Universitaire de Toulouse, 31432 Toulouse, France
| | - Jérémy Fauconnier
- INSERM U1046, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Céline Mias
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | - Bruno Payré
- Centre de Microscopie Électronique Appliquée à la Biologie, Faculté de Médecine Rangueil, 31062 Toulouse, France
| | - Louise Chopinet
- CNRS, LAAS, F-31400 Toulouse, France; CNRS, IPBS-UMR5089, F-31077 Toulouse, France
| | - David Alsteens
- Institute of Life Sciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Sandor Kasas
- Department of Cellular Biology and Morphology, Université de Lausanne, Institut de Physique des Systèmes Biologiques, École Polytechnique Fédérale de Lausanne, Switzerland
| | - Childerick Severac
- CNRS, ITAV-USR3505, Toulouse, France; Université de Toulouse, ITAV, LAAS, F-31400 Toulouse France
| | - Jérôme Thireau
- INSERM U1046, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Christophe Heymes
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | - Benjamin Honton
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | - Alain Lacampagne
- INSERM U1046, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Atul Pathak
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France; Department of Clinical Pharmacology, Centre Hospitalier Universitaire de Toulouse, F-31432 Toulouse, France
| | - Jean-Michel Sénard
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France; Department of Clinical Pharmacology, Centre Hospitalier Universitaire de Toulouse, F-31432 Toulouse, France
| | - Céline Galés
- CNRS, ITAV-USR3505, Toulouse, France; Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France.
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214
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Liu J, Li J. Detection of erythrocytes in patients with Waldenstrom macroglobulinemia using atomic force microscopy. Acta Biochim Biophys Sin (Shanghai) 2014; 46:420-5. [PMID: 24675428 DOI: 10.1093/abbs/gmu015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The pathological changes of erythrocytes are detected at the nanometer scale, which is important for revealing the onset of diseases and diagnosis. The aim of this study is to examine the ultrastructural changes of erythrocytes in Waldenström macroglobulinemia (WM) at a nanometer scale. Blood samples were collected from two healthy volunteers, two WM patients, and three multiple myeloma (MM) patients when they were first diagnosed. The changes of morphology in the erythrocytes were studied at the nanometer level by high-resolution atomic force microscopy imaging (AFM). Compared with the healthy controls and the MM patients, there were dramatic deformations in the overall shape and surface membrane of the erythrocytes in WM patients. Healthy, pathological WM, and MM erythrocytes could be distinguished by several morphological parameters, including the width, length, length-to-width ratio, valley, peak, peak-to-valley, and Ra. AFM is able to detect the morphological differences in the red blood cells from WM patients, healthy controls, and MM patients. Therefore, the erythrocyte morphology is an important parameter for the diagnosis of WM, which can be used to distinguish WM from MM. The changes of ultrastructure in red blood cells may provide a clue to reveal the mechanism of WM.
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Affiliation(s)
- Junru Liu
- Department of Hematology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
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215
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Affiliation(s)
- Kuo-Kang Liu
- School of Engineering, University of Warwick, Coventry CV4 7AL, UK
| | - Michelle L. Oyen
- Engineering Department, Cambridge University, Trumpington St., Cambridge CB2 1PZ, UK
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216
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Taffetani M, Griebel M, Gastaldi D, Klisch S, Vena P. Poroviscoelastic finite element model including continuous fiber distribution for the simulation of nanoindentation tests on articular cartilage. J Mech Behav Biomed Mater 2014; 32:17-30. [DOI: 10.1016/j.jmbbm.2013.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 11/30/2013] [Accepted: 12/02/2013] [Indexed: 11/28/2022]
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217
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Resveratrol protects chondrocytes from apoptosis via altering the ultrastructural and biomechanical properties: an AFM study. PLoS One 2014; 9:e91611. [PMID: 24632762 PMCID: PMC3954736 DOI: 10.1371/journal.pone.0091611] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/12/2014] [Indexed: 11/19/2022] Open
Abstract
Osteoarthritis (OA), a degenerative joint disease with high prevalence among older people, occurs from molecular or nanometer level and extends gradually to higher degrees of the ultrastructure of cartilage, finally resulting in irreversible structural and functional damages. This report aims to use atomic force microscopy (AFM) to investigate the protective effects of resveratrol (RV), a drug with good anti-inflammatory properties, on cellular morphology, membrane architecture, cytoskeleton, cell surface adhesion and stiffness at nanometer level in sodium nitroprusside (SNP)-induced apoptotic chondrocytes, a typical cellular OA model. CCK-8 assay showed that 100 μM RV significantly prevented SNP-induced cytotoxicity. AFM imaging and quantitative analysis showed that SNP potently induced chondrocytes changes including shrunk, round, lamellipodia contraction and decrease in adherent junctions among cells, as well as the destruction of biomechanics: 90% decrease in elasticity and 30% decrease in adhesion. In addition, confocal imaging analysis showed that SNP induced aggregation of the cytoskeleton and decrease in the expression of cytoskeletal proteins. More importantly, these SNP-induced damages to chondrocytes could be potently prevented by RV pretreatment. Interestingly, the biomechanical changes occurred before morphological changes could be clearly observed during SNP-induced apoptosis, indicating that the biomechanics of cellular membrane may be a more robust indicator of cell function. Collectively, our data demonstrate that RV prevents SNP-induced apoptosis of chondrocytes by regulating actin organization, and that AFM-based technology can be developed into a powerful and sensitive method to study the interaction mechanisms between chondrocytes and drugs.
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218
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RAUKER JOSIP, MOSHTAGH PARISAR, WEINANS HARRIE, ZADPOOR AMIRA. ANALYTICAL RELATIONSHIPS FOR NANOINDENTATION-BASED ESTIMATION OF MECHANICAL PROPERTIES OF BIOMATERIALS. J MECH MED BIOL 2014. [DOI: 10.1142/s021951941430004x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nanoindentation is an (almost) non-invasive method for obtaining material properties of different types of materials from the interpretation of experimental data related to indenter load (P) and penetration depth (h). In most cases, the material properties that are obtained by nanoindentation are elastic modulus (E), shear modulus (G) and hardness (H). The main advantages of this method are that no extensive preparation of the test specimen is required and that the mechanical properties can be probed at small scales. Moreover, nanoindentation test procedure is automated and the test equipment is easy to use. In this paper, we review different analytical methods that could be used for obtaining the mechanical properties of biomaterials based on the force-displacement curves generated by nanoindentation machines. Some practical issues including different types of machines and tips, calibration of nano-indentation machines, sources of error and specimen preparation are also briefly discussed. The main interest of this paper is the elastic behavior of biological tissues and biomaterials. Nevertheless, there is one section on elasto-plasticity, because purely elastic deformation of linearly elastic materials is difficult to achieve. The analytical solutions found in the literature for different material models are presented including the relationships found for linear elastic, elasto-plastic, hyperelastic, viscoelastic and poroelastic materials. These material models are relevant material models for studies of biological tissues and biomaterials.
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Affiliation(s)
- JOSIP RAUKER
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands
| | - PARISA R. MOSHTAGH
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands
| | - HARRIE WEINANS
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands
- Department of Orthopaedics and Department of Rheumatology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - AMIR A. ZADPOOR
- Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands
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219
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Rojas FP, Batista MA, Lindburg CA, Dean D, Grodzinsky AJ, Ortiz C, Han L. Molecular adhesion between cartilage extracellular matrix macromolecules. Biomacromolecules 2014; 15:772-80. [PMID: 24491174 PMCID: PMC3983133 DOI: 10.1021/bm401611b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
In this study, we investigated the
molecular adhesion between the
major constituents of cartilage extracellular matrix, namely, the
highly negatively charged proteoglycan aggrecan and the type II/IX/XI
fibrillar collagen network, in simulated physiological conditions.
Colloidal force spectroscopy was applied to measure the maximum adhesion
force and total adhesion energy between aggrecan end-attached spherical
tips (end radius R ≈ 2.5 μm) and trypsin-treated
cartilage disks with undamaged collagen networks. Studies were carried
out in various aqueous solutions to reveal the physical factors that
govern aggrecan–collagen adhesion. Increasing both ionic strength
and [Ca2+] significantly increased adhesion, highlighting
the importance of electrostatic repulsion and Ca2+-mediated
ion bridging effects. In addition, we probed how partial enzymatic
degradation of the collagen network, which simulates osteoarthritic
conditions, affects the aggrecan–collagen interactions. Interestingly,
we found a significant increase in aggrecan–collagen adhesion
even when there were no detectable changes at the macro- or microscales.
It is hypothesized that the aggrecan–collagen adhesion, together
with aggrecan–aggrecan self-adhesion, works synergistically
to determine the local molecular deformability and energy dissipation
of the cartilage matrix, in turn, affecting its macroscopic tissue
properties.
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Affiliation(s)
- Fredrick P Rojas
- Departments of Materials Science and Engineering, §Mechanical Engineering, ∥Biological Engineering, and ⊥Electrical Engineering and Computer Science, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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220
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Stan G, Solares SD, Pittenger B, Erina N, Su C. Nanoscale mechanics by tomographic contact resonance atomic force microscopy. NANOSCALE 2014; 6:962-9. [PMID: 24287978 DOI: 10.1039/c3nr04981g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We report on quantifiable depth-dependent contact resonance AFM (CR-AFM) measurements over polystyrene-polypropylene (PS-PP) blends to detail surface and sub-surface features in terms of elastic modulus and mechanical dissipation. The depth-dependences of the measured parameters were analyzed to generate cross-sectional images of tomographic reconstructions. Through a suitable normalization of the measured contact stiffness and indentation depth, the depth-dependence of the contact stiffness was analyzed by linear fits to obtain the elastic moduli of the materials probed. Besides elastic moduli, the contributions of adhesive forces (short-range versus long-range) to contact on each material were determined without a priori assumptions. The adhesion analysis was complemented by an unambiguous identification of distinct viscous responses during adhesion and in-contact deformation from the dissipated power during indentation.
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Affiliation(s)
- Gheorghe Stan
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
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221
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Akhtar R. In vitro characterisation of arterial stiffening: From the macro- to the nano-scale. Artery Res 2014. [DOI: 10.1016/j.artres.2014.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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222
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Shao J, Lin L, Tang B, Du C. Structure and nanomechanics of collagen fibrils in articular cartilage at different stages of osteoarthritis. RSC Adv 2014. [DOI: 10.1039/c4ra08997a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This study aimed to investigate the variation of structure and nanomechanical properties of human articular cartilage (AC) at different stages of osteoarthritis (OA).
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Affiliation(s)
- Jundong Shao
- Department of Materials Science and Engineering
- South University of Science and Technology of China
- Shenzhen 518055, PR China
- School of Materials Science and Engineering
- South China University of Technology
| | - Lijun Lin
- Department of Orthopedics
- Zhujiang Hospital
- Southern Medical University
- Guangzhou, China
| | - Bin Tang
- Department of Materials Science and Engineering
- South University of Science and Technology of China
- Shenzhen 518055, PR China
| | - Chang Du
- School of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510641, PR China
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223
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Wilusz RE, Zauscher S, Guilak F. Micromechanical mapping of early osteoarthritic changes in the pericellular matrix of human articular cartilage. Osteoarthritis Cartilage 2013; 21:1895-903. [PMID: 24025318 PMCID: PMC3856176 DOI: 10.1016/j.joca.2013.08.026] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 08/26/2013] [Accepted: 08/29/2013] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Osteoarthritis (OA) is a degenerative joint disease characterized by the progressive loss of articular cartilage. While macroscale degradation of the cartilage extracellular matrix (ECM) has been extensively studied, microscale changes in the chondrocyte pericellular matrix (PCM) and immediate microenvironment with OA are not fully understood. The objective of this study was to quantify osteoarthritic changes in the micromechanical properties of the ECM and PCM of human articular cartilage in situ using atomic force microscopy (AFM). METHOD AFM elastic mapping was performed on cryosections of human cartilage harvested from both condyles of macroscopically normal and osteoarthritic knee joints. This method was used to test the hypotheses that both ECM and PCM regions exhibit a loss of mechanical properties with OA and that the size of the PCM is enlarged in OA cartilage as compared to normal tissue. RESULTS Significant decreases were observed in both ECM and PCM moduli of 45% and 30%, respectively, on the medial condyle of OA knee joints as compared to cartilage from macroscopically normal joints. Enlargement of the PCM, as measured biomechanically, was also observed in medial condyle OA cartilage, reflecting the underlying distribution of type VI collagen in the region. No significant differences were observed in elastic moduli or their spatial distribution on the lateral condyle between normal and OA joints. CONCLUSION Our findings provide new evidence of significant site-specific degenerative changes in the chondrocyte micromechanical environment with OA.
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Affiliation(s)
- Rebecca E. Wilusz
- Department of Orthopaedic Surgery, Duke University Medical Center
- Department of Biomedical Engineering, Duke University
| | - Stefan Zauscher
- Department of Mechanical Engineering and Materials Science, Duke University
| | - Farshid Guilak
- Department of Orthopaedic Surgery, Duke University Medical Center
- Department of Biomedical Engineering, Duke University
- Department of Mechanical Engineering and Materials Science, Duke University
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224
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Attili S, Richter RP. Self-assembly and elasticity of hierarchical proteoglycan–hyaluronan brushes ††Electronic supplementary information (ESI) available: Variations in areal mass density upon SLB and SAv monolayer formation determined by SE (Fig. S1). See DOI: 10.1039/c3sm51213dClick here for additional data file. . SOFT MATTER 2013; 9. [PMCID: PMC4080815 DOI: 10.1039/c3sm51213d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We assemble aggrecan-containing hyaluronan brushes to study how the supramolecular structure and dynamics relate to material properties in hyaluronan-rich pericellular matrices.
Spatially confined yet strongly hydrated assemblies made from the proteoglycan aggrecan and the polysaccharide hyaluronan (HA) are major, functionally important components of the pericellular space around chondrocytes, and in cartilage. To better understand, how mechanical properties arise from the supramolecular structure and dynamics of such assemblies, we have studied the effect of aggrecan on the physico-chemical properties of well-defined, planar HA brushes. From interaction studies by quartz crystal microbalance with dissipation monitoring and spectroscopic ellipsometry, and compression studies by combined colloidal probe atomic force/reflection interference contrast microscopy, we find that aggrecan readily intercalates into HA brushes in a reversible manner. Aggrecan induces a drastic swelling of HA brushes, generating self-assembled films of several micrometers in thickness that are highly hydrated (>99%), elastic and very soft. The Young modulus in the linear compression regime is well below 100 Pa, and reaches several kPa at strong compression. The implications of these findings for biological function are discussed.
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Affiliation(s)
- Seetharamaiah Attili
- CIC biomaGUNE , Biosurfaces Unit , Paseo Miramon 182 , 20009 San Sebastian , Spain . ; Tel: +34 943 0053 29
- Max Planck Institute for Intelligent Systems , Heisenbergstraße 3 , 70569 Stuttgart , Germany
| | - Ralf P. Richter
- CIC biomaGUNE , Biosurfaces Unit , Paseo Miramon 182 , 20009 San Sebastian , Spain . ; Tel: +34 943 0053 29
- Max Planck Institute for Intelligent Systems , Heisenbergstraße 3 , 70569 Stuttgart , Germany
- J. Fourier University , Department of Molecular Chemistry , Laboratory I2BM , 570 Rue de la Chimie , 38041 Grenoble Cedex 9 , France
- University of the Basque Country , Department of Biochemistry and Molecular Biology , Barrio Sarriena s/n , 48940 Leioa , Spain
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225
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Pillet F, Chopinet L, Formosa C, Dague E. Atomic Force Microscopy and pharmacology: from microbiology to cancerology. Biochim Biophys Acta Gen Subj 2013; 1840:1028-50. [PMID: 24291690 DOI: 10.1016/j.bbagen.2013.11.019] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/18/2013] [Accepted: 11/20/2013] [Indexed: 02/06/2023]
Abstract
BACKGROUND Atomic Force Microscopy (AFM) has been extensively used to study biological samples. Researchers take advantage of its ability to image living samples to increase our fundamental knowledge (biophysical properties/biochemical behavior) on living cell surface properties, at the nano-scale. SCOPE OF REVIEW AFM, in the imaging modes, can probe cells morphological modifications induced by drugs. In the force spectroscopy mode, it is possible to follow the nanomechanical properties of a cell and to probe the mechanical modifications induced by drugs. AFM can be used to map single molecule distribution at the cell surface. We will focus on a collection of results aiming at evaluating the nano-scale effects of drugs, by AFM. Studies on yeast, bacteria and mammal cells will illustrate our discussion. Especially, we will show how AFM can help in getting a better understanding of drug mechanism of action. MAJOR CONCLUSIONS This review demonstrates that AFM is a versatile tool, useful in pharmacology. In microbiology, it has been used to study the drugs fighting Candida albicans or Pseudomonas aeruginosa. The major conclusions are a better understanding of the microbes' cell wall and of the drugs mechanism of action. In cancerology, AFM has been used to explore the effects of cytotoxic drugs or as an innovative diagnostic technology. AFM has provided original results on cultured cells, cells extracted from patient and directly on patient biopsies. GENERAL SIGNIFICANCE This review enhances the interest of AFM technologies for pharmacology. The applications reviewed range from microbiology to cancerology.
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Affiliation(s)
- Flavien Pillet
- CNRS, LAAS, 7 avenue du colonel Roche, F-31077 Toulouse Cedex 4, France; Université de Toulouse, UPS, INSA, INP, ISAE, UT1, UTM, LAAS, ITAV, F-31077 Toulouse Cedex 4, France
| | - Louise Chopinet
- CNRS, IPBS-UMR 5089, BP64182, 205 route de Narbonne, F-31077 Toulouse Cedex 4, France; Université de Toulouse, UPS, INSA, INP, ISAE, UT1, UTM, LAAS, ITAV, F-31077 Toulouse Cedex 4, France
| | - Cécile Formosa
- CNRS, LAAS, 7 avenue du colonel Roche, F-31077 Toulouse Cedex 4, France; Université de Toulouse, UPS, INSA, INP, ISAE, UT1, UTM, LAAS, ITAV, F-31077 Toulouse Cedex 4, France; CNRS, UMR 7565, SRSMC, Vandoeuvre-lès-Nancy, France; Université de Lorraine, UMR 7565, Faculté de Pharmacie, Nancy, France
| | - Etienne Dague
- CNRS, LAAS, 7 avenue du colonel Roche, F-31077 Toulouse Cedex 4, France; Université de Toulouse, UPS, INSA, INP, ISAE, UT1, UTM, LAAS, ITAV, F-31077 Toulouse Cedex 4, France; CNRS; ITAV-USR 3505; F31106 Toulouse, France.
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226
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Peñuela L, Wolf F, Raiteri R, Wendt D, Martin I, Barbero A. Atomic force microscopy to investigate spatial patterns of response to interleukin-1beta in engineered cartilage tissue elasticity. J Biomech 2013; 47:2157-64. [PMID: 24290139 DOI: 10.1016/j.jbiomech.2013.10.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/21/2013] [Accepted: 10/26/2013] [Indexed: 01/15/2023]
Abstract
Atomic force microscopy (AFM) has been proposed as a tool to evaluate the structural and mechanical properties of cartilage tissue. Here, we aimed at assessing whether AFM can be employed to quantify spatially resolved elastic response of tissue engineered cartilage (TEC) to short exposure to IL-1β, thus mimicking the initially inflammatory implantation site. TEC generated by 14 days of pellet-culture of expanded human chondrocytes was left untreated (ctr) or exposed to IL-1β for 3 days. TEC pellets were then cut in halves that were glued on a Petri dish. Profiles of elasticity were obtained by sampling with a nanometer sized, pyramidal indenting tip, with 200µm step resolution, the freshly exposed surfaces along selected directions. Replicate TECs were analyzed biochemically and histologically. GAG contents and elasticity of pellets decreased (1.4- and 2.6-fold, respectively, p<0.05) following IL-1β stimulation. Tissue quality was evaluated by scoring histological pictures taken at 200μm intervals, using the Bern-score grading system. At each distance, scores of ctr TEC were higher than those IL-1β treated, with the largest differences between the two groups observed in the central regions. Consistent with the histological results, elasticity of IL-1β-treated TEC was lower than in ctr pellets (up to 3.4-fold at 200μm from the center). IL-1β treated but not ctr TEC was intensely stained for MMP-13 and DIPEN (cryptic fragment of aggrecan) especially in the central regions. The findings indicate the potential of AFM to investigate structure/function relationships in TEC and to perform tests aimed at predicting the functionality of TEC upon implantation.
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Affiliation(s)
- Leonardo Peñuela
- Department of Informatics, Bioengineering, Robotics, and System Engineering, University of Genova, Genova, Italy
| | - Francine Wolf
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Roberto Raiteri
- Department of Informatics, Bioengineering, Robotics, and System Engineering, University of Genova, Genova, Italy
| | - David Wendt
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Ivan Martin
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland.
| | - Andrea Barbero
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
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227
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Nia HT, Bozchalooi IS, Li Y, Han L, Hung HH, Frank E, Youcef-Toumi K, Ortiz C, Grodzinsky A. High-bandwidth AFM-based rheology reveals that cartilage is most sensitive to high loading rates at early stages of impairment. Biophys J 2013; 104:1529-37. [PMID: 23561529 DOI: 10.1016/j.bpj.2013.02.048] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/12/2013] [Accepted: 02/19/2013] [Indexed: 11/25/2022] Open
Abstract
Utilizing a newly developed atomic-force-microscopy-based wide-frequency rheology system, we measured the dynamic nanomechanical behavior of normal and glycosaminoglycan (GAG)-depleted cartilage, the latter representing matrix degradation that occurs at the earliest stages of osteoarthritis. We observed unique variations in the frequency-dependent stiffness and hydraulic permeability of cartilage in the 1 Hz-to-10 kHz range, a frequency range that is relevant to joint motions from normal ambulation to high-frequency impact loading. Measurement in this frequency range is well beyond the capabilities of typical commercial atomic force microscopes. We showed that the dynamic modulus of cartilage undergoes a dramatic alteration after GAG loss, even with the collagen network still intact: whereas the magnitude of the dynamic modulus decreased two- to threefold at higher frequencies, the peak frequency of the phase angle of the modulus (representing fluid-solid frictional dissipation) increased 15-fold from 55 Hz in normal cartilage to 800 Hz after GAG depletion. These results, based on a fibril-reinforced poroelastic finite-element model, demonstrated that GAG loss caused a dramatic increase in cartilage hydraulic permeability (up to 25-fold), suggesting that early osteoarthritic cartilage is more vulnerable to higher loading rates than to the conventionally studied "loading magnitude". Thus, over the wide frequency range of joint motion during daily activities, hydraulic permeability appears the most sensitive marker of early tissue degradation.
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Affiliation(s)
- Hadi Tavakoli Nia
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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228
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Swift J, Ivanovska IL, Buxboim A, Harada T, Dingal PCDP, Pinter J, Pajerowski JD, Spinler KR, Shin JW, Tewari M, Rehfeldt F, Speicher DW, Discher DE. Nuclear lamin-A scales with tissue stiffness and enhances matrix-directed differentiation. Science 2013; 341:1240104. [PMID: 23990565 DOI: 10.1126/science.1240104] [Citation(s) in RCA: 1295] [Impact Index Per Article: 117.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Tissues can be soft like fat, which bears little stress, or stiff like bone, which sustains high stress, but whether there is a systematic relationship between tissue mechanics and differentiation is unknown. Here, proteomics analyses revealed that levels of the nucleoskeletal protein lamin-A scaled with tissue elasticity, E, as did levels of collagens in the extracellular matrix that determine E. Stem cell differentiation into fat on soft matrix was enhanced by low lamin-A levels, whereas differentiation into bone on stiff matrix was enhanced by high lamin-A levels. Matrix stiffness directly influenced lamin-A protein levels, and, although lamin-A transcription was regulated by the vitamin A/retinoic acid (RA) pathway with broad roles in development, nuclear entry of RA receptors was modulated by lamin-A protein. Tissue stiffness and stress thus increase lamin-A levels, which stabilize the nucleus while also contributing to lineage determination.
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Affiliation(s)
- Joe Swift
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104, USA
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229
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Rabus M, Söllradl T, Clausen-Schaumann H, Laforsch C. Uncovering ultrastructural defences in Daphnia magna--an interdisciplinary approach to assess the predator-induced fortification of the carapace. PLoS One 2013; 8:e67856. [PMID: 23776711 PMCID: PMC3680394 DOI: 10.1371/journal.pone.0067856] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 05/28/2013] [Indexed: 12/02/2022] Open
Abstract
The development of structural defences, such as the fortification of shells or exoskeletons, is a widespread strategy to reduce predator attack efficiency. In unpredictable environments these defences may be more pronounced in the presence of a predator. The cladoceran Daphniamagna (Crustacea: Branchiopoda: Cladocera) has been shown to develop a bulky morphotype as an effective inducible morphological defence against the predatory tadpole shrimp Triopscancriformis (Crustacea: Branchiopoda: Notostraca). Mediated by kairomones, the daphnids express an increased body length, width and an elongated tail spine. Here we examined whether these large scale morphological defences are accompanied by additional ultrastructural defences, i.e. a fortification of the exoskeleton. We employed atomic force microscopy (AFM) based nanoindentation experiments to assess the cuticle hardness along with tapping mode AFM imaging to visualise the surface morphology for predator exposed and non-predator exposed daphnids. We used semi-thin sections of the carapace to measure the cuticle thickness, and finally, we used fluorescence microscopy to analyse the diameter of the pillars connecting the two carapace layers. We found that D. magna indeed expresses ultrastructural defences against Triops predation. The cuticle in predator exposed individuals is approximately five times harder and two times thicker than in control daphnids. Moreover, the pillar diameter is significantly increased in predator exposed daphnids. These predator-cue induced changes in the carapace architecture should provide effective protection against being crushed by the predator’s mouthparts and may add to the protective effect of bulkiness. This study highlights the potential of interdisciplinary studies to uncover new and relevant aspects even in extensively studied fields of research.
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Affiliation(s)
- Max Rabus
- Department of Biology II, Ludwig-Maximilians-University Munich, Germany.
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230
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Dokukin M, Guz N, Sokolov I. Quantitative study of the elastic modulus of loosely attached cells in AFM indentation experiments. Biophys J 2013; 104:2123-31. [PMID: 23708352 PMCID: PMC3660635 DOI: 10.1016/j.bpj.2013.04.019] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Revised: 03/31/2013] [Accepted: 04/04/2013] [Indexed: 02/07/2023] Open
Abstract
When measuring the elastic (Young's) modulus of cells using AFM, good attachment of cells to a substrate is paramount. However, many cells cannot be firmly attached to many substrates. A loosely attached cell is more compliant under indenting. It may result in artificially low elastic modulus when analyzed with the elasticity models assuming firm attachment. Here we suggest an AFM-based method/model that can be applied to extract the correct Young's modulus of cells loosely attached to a substrate. The method is verified by using primary breast epithelial cancer cells (MCF-7) at passage 4. At this passage, approximately one-half of cells develop enough adhesion with the substrate to be firmly attached to the substrate. These cells look well spread. The other one-half of cells do not develop sufficient adhesion, and are loosely attached to the substrate. These cells look spherical. When processing the AFM indentation data, a straightforward use of the Hertz model results in a substantial difference of the Young's modulus between these two types of cells. If we use the model presented here, we see no statistical difference between the values of the Young's modulus of both poorly attached (round) and firmly attached (close to flat) cells. In addition, the presented model allows obtaining parameters of the brush surrounding the cells. The cellular brush observed is also statistically identical for both types of cells. The method described here can be applied to study mechanics of many other types of cells loosely attached to substrates, e.g., blood cells, some stem cells, cancerous cells, etc.
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Affiliation(s)
- Maxim E. Dokukin
- Department of Mechanical Engineering, Tufts University, Medford, Massachusetts
- Department of Physics, Clarkson University, Potsdam, New York
| | - Nataliia V. Guz
- Department of Physics, Clarkson University, Potsdam, New York
| | - Igor Sokolov
- Department of Mechanical Engineering, Tufts University, Medford, Massachusetts
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
- Department of Physics, Clarkson University, Potsdam, New York
- Nanoengineering and Biotechnology Laboratories Center, Clarkson University, Potsdam, New York
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231
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McCarthy I, Hodgins D, Mor A, Elbaz A, Segal G. Analysis of knee flexion characteristics and how they alter with the onset of knee osteoarthritis: a case control study. BMC Musculoskelet Disord 2013; 14:169. [PMID: 23692671 PMCID: PMC3663779 DOI: 10.1186/1471-2474-14-169] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 05/14/2013] [Indexed: 11/30/2022] Open
Abstract
Background The purpose of this study was to examine the differences in gait profile between patients with knee osteoarthritis (OA) and healthy control and to create motion characteristics that will differentiate between them. Methods Twenty three patients diagnosed with knee OA and 21 healthy matched controls underwent a gait test using a sensor system (gaitWALK). Gait parameters evaluated were: stride duration, knee flexion range of motion (ROM) in swing and stance. T-Test was used to evaluate significant differences between groups (P < 0.05). Results Patients with knee OA had significant lower knee flexion ROM (10.3° ± 4.0°) during stance than matched controls (18.0° ± 4.0°) (p < 0.001). Patients with knee OA had significant lower knee flexion ROM (54.8° ± 5.5°) during swing than matched controls (61.2° ± 6.1) (p = 0.003). Patients with knee OA also had longer stride duration (1.12 s ± 0.09 s) than matched controls (1.06 s ± 0.11 s), but this was not statistically significant (p = 0.073). Motion characteristics differentiate between a patient with knee OA and a healthy one with a sensitivity of 0.952 and a specificity of 0.783. Conclusions Significant differences were found in the gait profile of patients with knee OA compared to matched control and motion characteristics were identified. This test might help clinicians identify and evaluate a knee problem in a simple gait test.
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Affiliation(s)
- Ian McCarthy
- Royal National Orthopaedic Hospital, Stanmore, UK
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232
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Lee SS, Duong CT, Park SH, Cho Y, Park S, Park S. Frictional response of normal and osteoarthritic articular cartilage in human femoral head. Proc Inst Mech Eng H 2013; 227:129-37. [PMID: 23513984 DOI: 10.1177/0954411912462815] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We evaluated the microscale frictional response of human articular cartilage in different osteoarthritis stages using an atomic force microscope. Four human femoral heads (60-80 years old) with different osteoarthritis stages were explanted, and two cylindrical cartilage samples were sectioned from each femoral head. The microscale frictional coefficient mu of human cartilage in phosphate-buffered saline increased with increasing osteoarthritis stages, resulting in mu = 0.119 +/- 0.036 for stage 0 (normal cartilage), 0.151 +/- 0.039 for stage I, 0.158 +/- 0.041 for stage 2, and 0.409 +/- 0.119 for stage 3. Statistically significant differences of mu values for different osteoarthritis stages were detected only between stage 3 and other stages (p < 0.0001). The average surface roughness Rq significantly increased with increasing osteoarthritis stages, ranging from 137 +/- 25 nm for stage 0 to 533 +/- 196 nm for stage 3. A significant correlation between mu and Rq for different osteoarthritis stages was observed (R2 = 0.981). These results demonstrate a positive correlation between the osteoarthritis stages and cartilage surface roughness, and the dependence of the human cartilage frictional response, on osteoarthritis progression. The results could be due to a decrease in the superficial zone protein concentration during the natural progression of osteoarthritis.
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Affiliation(s)
- Sang-Soo Lee
- Orthopedic Surgery and Institute for Skeletal Aging, College of Medicine, Hallym University, Chuncheon, Republic of Korea
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233
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Desrochers J, Amrein MW, Matyas JR. Microscale surface friction of articular cartilage in early osteoarthritis. J Mech Behav Biomed Mater 2013; 25:11-22. [PMID: 23726921 DOI: 10.1016/j.jmbbm.2013.03.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 03/04/2013] [Accepted: 03/13/2013] [Indexed: 10/27/2022]
Abstract
Articular cartilage forms the articulating surface of long bones and facilitates energy dissipation upon loading as well as joint lubrication and wear resistance. In normal cartilage, boundary lubrication between thin films at the cartilage surface reduces friction in the absence of interstitial fluid pressurization and fluid film lubrication by synovial fluid. Inadequate boundary lubrication is associated with degenerative joint conditions such as osteoarthritis (OA), but relations between OA and surface friction, lubrication and wear in boundary lubrication are not well defined. The purpose of the present study was to measure microscale boundary mode friction of the articular cartilage surface in an in vivo experimental model to better understand changes in cartilage surface friction in early OA. Cartilage friction was measured on the articular surface by atomic force microscopy (AFM) under applied loads ranging from 0.5 to 5 μN. Microscale AFM friction analyses revealed depth dependent changes within the top-most few microns of the cartilage surface in this model of early OA. A significant increase of nearly 50% was observed in the mean engineering friction coefficient for OA cartilage at the 0.5 μN load level; no significant differences in friction coefficients were found under higher applied loads. Changes in cartilage surface morphology observed by scanning electron microscopy included cracking and roughening of the surface indicative of disruption and wear accompanied by an apparent disintegration of the thin surface lamina from the underlying matrix. Immunohistochemical staining of lubricin - an important cartilage surface boundary lubricant - did not reveal differences in spatial distribution near the cartilage surface in OA compared to controls. The increase in friction at the 0.5 μN force level is interpreted to reflect changes in the interfacial mechanics of the thin surface lamina of articular cartilage: increased friction implies reduced lubrication efficiency and a higher potential for cartilage surface wear in OA. The effects of mechanical or biochemical changes or loss of the thin surface lamina on the remaining tissue with respect to OA progression is unknown and requires further study, but preservation of the surface lamina seems an important early target for the maintenance of cartilage health and prevention of OA.
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Affiliation(s)
- Jane Desrochers
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada T2N 4N1.
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234
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AFM volumetric methods for the characterization of proteins and nucleic acids. Methods 2013; 60:113-21. [DOI: 10.1016/j.ymeth.2013.02.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/28/2013] [Accepted: 02/14/2013] [Indexed: 11/19/2022] Open
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235
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Dong S, Wang Q, Sun S, Liang Y, Jiang J, Liu L, Hu A, Cai J. Atomic force microscopy of chronic lymphatic leukaemia cells activation induced by Staphylococcus aureus. Cell Biol Int 2013; 37:380-6. [PMID: 23450797 DOI: 10.1002/cbin.10052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Accepted: 01/07/2013] [Indexed: 11/07/2022]
Abstract
Activation of lymphatic cells is associated with changes in morphology, ultrastructure and adhesion force. We have investigated the activation efficiency of Staphylococcus aureus (SAC) on B-cell chronic lymphatic leukaemia (B-CLL) cells using atomic force microscopy (AFM), and found changes in the above properties. Cell viability and proliferation were measured using Cell Counting Kit-8 (CCK-8) and enzyme-linked immunosorbent assay (ELISA). AFM clearly showed that the volume and nuclear-cytoplasm ratio of cells increased significantly with activated time. It also showed that pseudopodia and immunological synapses began to appear at 24 h. In the activation process, nano-structures of the cell surface became aggregated, and adhesion increased. In conclusion, the results indicate a close relationship between membrane reconstruction and multiplication process of B-CLL cells.
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Affiliation(s)
- Shisong Dong
- Department of Chemistry, Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
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236
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Abstract
Stick-slip friction was observed in articular cartilage under certain loading and sliding conditions and systematically studied. Using the Surface Forces Apparatus, we show that stick-slip friction can induce permanent morphological changes (a change in the roughness indicative of wear/damage) in cartilage surfaces, even under mild loading and sliding conditions. The different load and speed regimes can be represented by friction maps--separating regimes of smooth and stick-slip sliding; damage generally occurs within the stick-slip regimes. Prolonged exposure of cartilage surfaces to stick-slip sliding resulted in a significant increase of surface roughness, indicative of severe morphological changes of the cartilage superficial zone. To further investigate the factors that are conducive to stick-slip and wear, we selectively digested essential components of cartilage: type II collagen, hyaluronic acid (HA), and glycosaminoglycans (GAGs). Compared with the normal cartilage, HA and GAG digestions modified the stick-slip behavior and increased surface roughness (wear) during sliding, whereas collagen digestion decreased the surface roughness. Importantly, friction forces increased up to 2, 10, and 5 times after HA, GAGs, and collagen digestion, respectively. Also, each digestion altered the friction map in different ways. Our results show that (i) wear is not directly related to the friction coefficient but (ii) more directly related to stick-slip sliding, even when present at small amplitudes, and that (iii) the different molecular components of joints work synergistically to prevent wear. Our results also suggest potential noninvasive diagnostic tools for sensing stick-slip in joints.
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237
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Irie T, Oda K, Shiino A, Kubo M, Morikawa S, Urushiyama N, Aonuma S, Kimura T, Inubushi T, Oohashi T, Komatsu N. Design, synthesis, and preliminary ex vivo and in vivo evaluation of cationic magnetic resonance contrast agent for rabbit articular cartilage imaging. MEDCHEMCOMM 2013. [DOI: 10.1039/c3md00229b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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238
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Rettler E, Hoeppener S, Sigusch BW, Schubert US. Mapping the mechanical properties of biomaterials on different length scales: depth-sensing indentation and AFM based nanoindentation. J Mater Chem B 2013; 1:2789-2806. [DOI: 10.1039/c3tb20120a] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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239
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Kemp AD, Harding CC, Cabral WA, Marini JC, Wallace JM. Effects of tissue hydration on nanoscale structural morphology and mechanics of individual Type I collagen fibrils in the Brtl mouse model of Osteogenesis Imperfecta. J Struct Biol 2012; 180:428-38. [PMID: 23041293 PMCID: PMC3685442 DOI: 10.1016/j.jsb.2012.09.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 09/10/2012] [Accepted: 09/25/2012] [Indexed: 11/25/2022]
Abstract
Type I collagen is the most abundant protein in mammals, and is a vital part of the extracellular matrix for numerous tissues. Despite collagen's importance, little is known about its nanoscale morphology in tissues and how morphology relates to mechanical function. This study probes nanoscale structure and mechanical properties of collagen as a function of disease in native hydrated tendons. Wild type tendon and tendon from the Brtl/+ mouse model of Osteogenesis Imperfecta were investigated. An atomic force microscope (AFM) was used to image and indent minimally-processed collagen fibrils in hydrated and dehydrated conditions. AFM was used because of the ability to keep biological tissues as close to their native in situ conditions as possible. The study demonstrated phenotypic difference in Brtl/+ fibril morphology and mechanics in hydrated tendon which became more compelling upon dehydration. Dried tendons had a significant downward shift in fibril D-periodic spacing versus a shift up in wet tendons. Nanoscale changes in morphology in dry samples were accompanied by significant increases in modulus and adhesion force and decreased indentation depth. A minimal mechanical phenotype existed in hydrated samples, possibly due to water masking structural defects within the diseased fibrils. This study demonstrates that collagen nanoscale morphology and mechanics are impacted in Brtl/+ tendons, and that the phenotype can be modulated by the presence or absence of water. Dehydration causes artifacts in biological samples which require water and this factor must be considered for studies at any length scale in collagen-based tissues, especially when characterizing disease-induced differences.
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Affiliation(s)
- Arika D. Kemp
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA
| | - Chad C. Harding
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA
| | - Wayne A. Cabral
- Bone and Extracellular Matrix Branch, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH, Bethesda, MD, USA
| | - Joan C. Marini
- Bone and Extracellular Matrix Branch, The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH, Bethesda, MD, USA
| | - Joseph M. Wallace
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, USA
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240
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Khan IM, Francis L, Theobald PS, Perni S, Young RD, Prokopovich P, Conlan RS, Archer CW. In vitro growth factor-induced bio engineering of mature articular cartilage. Biomaterials 2012. [PMID: 23182922 PMCID: PMC3543901 DOI: 10.1016/j.biomaterials.2012.09.076] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Articular cartilage maturation is the postnatal development process that adapts joint surfaces to their site-specific biomechanical demands. Maturation involves gross morphological changes that occur through a process of synchronised growth and resorption of cartilage and generally ends at sexual maturity. The inability to induce maturation in biomaterial constructs designed for cartilage repair has been cited as a major cause for their failure in producing persistent cell-based repair of joint lesions. The combination of growth factors FGF2 and TGFβ1 induces accelerated articular cartilage maturation in vitro such that many molecular and morphological characteristics of tissue maturation are observable. We hypothesised that experimental growth factor-induced maturation of immature cartilage would result in a biophysical and biochemical composition consistent with a mature phenotype. Using native immature and mature cartilage as reference, we observed that growth factor-treated immature cartilages displayed increased nano-compressive stiffness, decreased surface adhesion, decreased water content, increased collagen content and smoother surfaces, correlating with a convergence to the mature cartilage phenotype. Furthermore, increased gene expression of surface structural protein collagen type I in growth factor-treated explants compared to reference cartilages demonstrates that they are still in the dynamic phase of the postnatal developmental transition. These data provide a basis for understanding the regulation of postnatal maturation of articular cartilage and the application of growth factor-induced maturation in vitro and in vivo in order to repair and regenerate cartilage defects.
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Affiliation(s)
- Ilyas M Khan
- Division of Pathophysiology and Repair, School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, Wales, UK.
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241
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Grant C, Twigg P, Tobin D. Static and dynamic nanomechanical properties of human skin tissue using atomic force microscopy: effect of scarring in the upper dermis. Acta Biomater 2012; 8:4123-9. [PMID: 22771457 DOI: 10.1016/j.actbio.2012.06.042] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/19/2012] [Accepted: 06/29/2012] [Indexed: 01/15/2023]
Abstract
Following traumatic injury, skin has the capacity to repair itself through a complex cascade of biochemical change. The dermis, which contains a load-bearing collagenous network structure, is remodelled over a long period of time, affecting its mechanical behaviour. This study examines the nanomechanical and viscoelastic properties of the upper dermis from human skin that includes both healthy intact and scarred tissue. Extensive nanoindentation analysis shows that the dermal scar tissue exhibits stiffer behaviour than the healthy intact skin. The scar skin also shows weaker viscoelastic creep and capability to dissipate energy at physiologically relevant frequencies than the adjacent intact skin. These results are discussed in conjunction with a visual change in the orientation of collagenous fibrils in the scarred dermis compared with normal dermis, as shown by atomic force microscopy imaging.
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242
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Plodinec M, Loparic M, Monnier CA, Obermann EC, Zanetti-Dallenbach R, Oertle P, Hyotyla JT, Aebi U, Bentires-Alj M, Lim RYH, Schoenenberger CA. The nanomechanical signature of breast cancer. NATURE NANOTECHNOLOGY 2012; 7:757-65. [PMID: 23085644 DOI: 10.1038/nnano.2012.167] [Citation(s) in RCA: 675] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 08/29/2012] [Indexed: 05/18/2023]
Abstract
Cancer initiation and progression follow complex molecular and structural changes in the extracellular matrix and cellular architecture of living tissue. However, it remains poorly understood how the transformation from health to malignancy alters the mechanical properties of cells within the tumour microenvironment. Here, we show using an indentation-type atomic force microscope (IT-AFM) that unadulterated human breast biopsies display distinct stiffness profiles. Correlative stiffness maps obtained on normal and benign tissues show uniform stiffness profiles that are characterized by a single distinct peak. In contrast, malignant tissues have a broad distribution resulting from tissue heterogeneity, with a prominent low-stiffness peak representative of cancer cells. Similar findings are seen in specific stages of breast cancer in MMTV-PyMT transgenic mice. Further evidence obtained from the lungs of mice with late-stage tumours shows that migration and metastatic spreading is correlated to the low stiffness of hypoxia-associated cancer cells. Overall, nanomechanical profiling by IT-AFM provides quantitative indicators in the clinical diagnostics of breast cancer with translational significance.
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Affiliation(s)
- Marija Plodinec
- Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
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243
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Stacey M, Dutta D, Cao W, Asmar A, Elsayed-Ali H, Kelly R, Beskok A. Atomic force microscopy characterization of collagen 'nanostraws' in human costal cartilage. Micron 2012; 44:483-7. [PMID: 23127510 DOI: 10.1016/j.micron.2012.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/25/2012] [Accepted: 10/10/2012] [Indexed: 11/26/2022]
Abstract
Costal cartilage, a type of hyaline cartilage that bridges the bony ribs and sternum, is relatively understudied compared to the load bearing cartilages. Deformities of costal cartilage can result in deformation of the chest wall, where the sternum is largely pushed toward or away from the spine, pectus excavatum and pectus carinatum, respectively, with each condition having significant clinical impact. In the absence of extensive literature describing morphological features of costal cartilage, we characterized a sample from the costal margin immunohistologically and through atomic force microscopy. We had previously observed the presence of collagen 'nanostraws' running the length of costal cartilage. Hypothesizing that these structures may be responsible for fluid flow within this thick, avascular tissue, and prior to microfluidic analysis, we estimated the diameters and measured Young's modulus of elasticity of the collagen nanostraws. We found significant differences in results between treatment type and fixation. Significant differences in nanostraw elasticity and diameter obviously affect nano-fluidic transport calculations, and therefore, we consider these results of importance to the scientific community relying upon measurements in the nanoscale.
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Affiliation(s)
- M Stacey
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
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244
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Wang M, Peng Z, Watson JA, Watson GS, Yin L. Nanoscale study of cartilage surfaces using atomic force microscopy. Proc Inst Mech Eng H 2012; 226:899-910. [DOI: 10.1177/0954411912460482] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Articulating cartilage wear plays an important role in cartilage degeneration and osteoarthritis (OA) progression. This study investigated the changes of mechanical properties and surface roughness of sheep cartilages with wear progression at a nanometre scale. Young sheep’s rear legs were subjected to a series of wear tests to generate worn cartilage samples to simulate the OA progression. Atomic force microscopy (AFM) was used to determine the effective indentation modulus and to measure the surface morphology of moist cartilage surfaces. The study has found that the mean effective indentation modulus values of worn cartilages were lower than that of healthy cartilage as the control sample. A medium-to-strong correlation between the effective indentation modulus values and the OA grades has been found. The relation between surface topography and effective indentation modulus values of the cartilage surfaces with OA progression was weakly correlated. The method established in this study can be implemented to investigate the effective indentation modulus values of clinical osteoarthritic cartilages and to assist in the understanding and assessment of OA.
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Affiliation(s)
- Meiling Wang
- School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - Zhongxiao Peng
- School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - Jolanta A Watson
- School of Pharmacy and Molecular Sciences, James Cook University, Townsville, QLD, Australia
| | - Gregory S Watson
- School of Pharmacy and Molecular Sciences, James Cook University, Townsville, QLD, Australia
| | - Ling Yin
- School of Engineering and Physical Sciences, James Cook University, Townsville, QLD, Australia
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245
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Shi X, Zhang X, Xia T, Fang X. Living cell study at the single-molecule and single-cell levels by atomic force microscopy. Nanomedicine (Lond) 2012; 7:1625-37. [DOI: 10.2217/nnm.12.130] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Atomic force microscopy (AFM) has been emerging as a multifunctional molecular tool in nanobiology and nanomedicine. This review summarizes the recent advances in AFM study of living mammalian cells at the single-molecule and single-cell levels. Besides nanoscale imaging of cell membrane structure, AFM-based force measurements on living cells are mainly discussed. These include the development and application of single-molecule force spectroscopy to investigate ligand–receptor binding strength and dissociation dynamics, and the characterization of cell mechanical properties in a physiological environment. Molecular manipulation of cells by AFM to change the cellular process is also described. Living-cell AFM study offers a new approach to understand the molecular mechanisms of cell function, disease development and drug effect, as well as to develop new strategies to achieve single-cell-based diagnosis.
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Affiliation(s)
- Xiaoli Shi
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
| | - Xuejie Zhang
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
| | - Tie Xia
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
| | - Xiaohong Fang
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
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246
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Mroue KH, MacKinnon N, Xu J, Zhu P, McNerny E, Kohn DH, Morris MD, Ramamoorthy A. High-resolution structural insights into bone: a solid-state NMR relaxation study utilizing paramagnetic doping. J Phys Chem B 2012; 116:11656-61. [PMID: 22953757 PMCID: PMC3460063 DOI: 10.1021/jp307935g] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hierarchical heterogeneous architecture of bone imposes significant challenges to structural and dynamic studies conducted by traditional biophysical techniques. High-resolution solid-state nuclear magnetic resonance (SSNMR) spectroscopy is capable of providing detailed atomic-level structural insights into such traditionally challenging materials. However, the relatively long data-collection time necessary to achieve a reliable signal-to-noise ratio (S/N) remains a major limitation for the widespread application of SSNMR on bone and related biomaterials. In this study, we attempt to overcome this limitation by employing the paramagnetic relaxation properties of copper(II) ions to shorten the (1)H intrinsic spin-lattice (T(1)) relaxation times measured in natural-abundance (13)C cross-polarization (CP) magic-angle-spinning (MAS) NMR experiments on bone tissues for the purpose of accelerating the data acquisition time in SSNMR. To this end, high-resolution solid-state (13)C CPMAS experiments were conducted on type I collagen (bovine tendon), bovine cortical bone, and demineralized bovine cortical bone, each in powdered form, to measure the (1)H T(1) values in the absence and in the presence of 30 mM Cu(II)(NH(4))(2)EDTA. Our results show that the (1)H T(1) values were successfully reduced by a factor of 2.2, 2.9, and 3.2 for bovine cortical bone, type I collagen, and demineralized bone, respectively, without reducing the spectral resolution and thus enabling faster data acquisition. In addition, paramagnetic quenching of particular (13)C NMR resonances on exposure to Cu(2+) ions in the absence of mineral was also observed, potentially suggesting the relative proximity of three main amino acids in the protein backbone (glycine, proline, and alanine) to the bone mineral surface.
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Affiliation(s)
- Kamal H. Mroue
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Neil MacKinnon
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Jiadi Xu
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Peizhi Zhu
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Erin McNerny
- School of Dentistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - David H. Kohn
- School of Dentistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Michael D. Morris
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
- Department of Chemistry, The University of Michigan, Ann Arbor, Michigan, 48109-1055, USA
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247
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Quantitative imaging of young's modulus of soft tissues from ultrasound water jet indentation: a finite element study. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2012; 2012:979847. [PMID: 22927890 PMCID: PMC3426275 DOI: 10.1155/2012/979847] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Accepted: 07/08/2012] [Indexed: 11/18/2022]
Abstract
Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young's modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson's ratio using Hayes' equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes' equation has been derived by introducing a new scaling factor which is dependent on Poisson's ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue), and deformation ratio d/h. With this model, the Young's modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%.
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248
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Formosa C, Grare M, Jauvert E, Coutable A, Regnouf-de-Vains JB, Mourer M, Duval RE, Dague E. Nanoscale analysis of the effects of antibiotics and CX1 on a Pseudomonas aeruginosa multidrug-resistant strain. Sci Rep 2012; 2:575. [PMID: 22893853 PMCID: PMC3418629 DOI: 10.1038/srep00575] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 07/30/2012] [Indexed: 12/02/2022] Open
Abstract
Drug resistance is a challenge that can be addressed using nanotechnology. We focused on the resistance of the bacteria Pseudomonas aeruginosa and investigated, using Atomic Force Microscopy (AFM), the behavior of a reference strain and of a multidrug resistant clinical strain, submitted to two antibiotics and to an innovative antibacterial drug (CX1). We measured the morphology, surface roughness and elasticity of the bacteria under physiological conditions and exposed to the antibacterial molecules. To go further in the molecules action mechanism, we explored the bacterial cell wall nanoscale organization using functionalized AFM tips. We have demonstrated that affected cells have a molecularly disorganized cell wall; surprisingly long molecules being pulled off from the cell wall by a lectin probe. Finally, we have elucidated the mechanism of action of CX1: it destroys the outer membrane of the bacteria as demonstrated by the results on artificial phospholipidic membranes and on the resistant strain.
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Affiliation(s)
- C Formosa
- Centre National de la Recherche Scientifique, Laboratoire d’Analyse et d’Architecture des Systèmes-LAAS, Toulouse, France
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249
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Wen CY, Wu CB, Tang B, Wang T, Yan CH, Lu WW, Pan H, Hu Y, Chiu KY. Collagen fibril stiffening in osteoarthritic cartilage of human beings revealed by atomic force microscopy. Osteoarthritis Cartilage 2012; 20:916-22. [PMID: 22548795 DOI: 10.1016/j.joca.2012.04.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 04/15/2012] [Accepted: 04/23/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This study aimed to characterize the in-situ mechanical property and morphology of individual collagen fibril in osteoarthritic cartilage using indentation-type atomic force microscopy (IT-AFM). METHODS The specimens with intact articular cartilage (AC), mild to severe degenerated cartilage from osteoarthritis (OA) were collected with informed consent from the postmenopausal women who underwent hip or knee arthroplasty. The fresh specimens were cryo-sectioned by layers with 50μm thick for each from the articular surface to calcified cartilage, and then processed for AFM imaging and nanoindentation test. For each layer, a total of 20 collagen fibrils were randomly selected for testing. AFM tips with the nominal radius less than 10nm were employed for probing the individual collagen fibril, and the obtained cantilever deflection signal and displacement were recorded for calculating its elastic modulus. RESULTS An intact AC exhibited a gradation in elastic modulus of collagen fibrils from articular surface (2.65 ± 0.31 GPa) to the cartilage-bone interface (3.70 ± 0.44 GPa). It was noted in mildly degenerated OA cartilage that the coefficient of variation for mechanical properties of collagen fibers, ranging from 25% to 48%, significantly increased as compared with intact one (12%). The stiffened collagen fibrils occurred at either articular surface (3.11 ± 0.91 GPa) or the cartilage-bone interface (5.64 ± 1.10 GPa), accompanied by loosely organized meshwork with advancement of OA cartilage degeneration. It was echoed by histological findings of OA cartilage, including fibrotic changes of surface region and tidemark irregularities. CONCLUSION The stiffened collagen fibrils in AC occurred with OA onset and progression, not only at articular surface but also the cartilage-bone interface.
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Affiliation(s)
- C-Y Wen
- Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong
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Stacey MW, Grubbs J, Asmar A, Pryor J, Elsayed-Ali H, Cao W, Beskok A, Dutta D, Darby DA, Fecteau A, Werner A, Kelly RE. Decorin expression, straw-like structure, and differentiation of human costal cartilage. Connect Tissue Res 2012; 53:415-21. [PMID: 22490077 DOI: 10.3109/03008207.2012.684113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Costal cartilage is much understudied compared with the load-bearing cartilages. Abnormally grown costal cartilages are associated with the inherited chest wall deformities pectus excavatum and pectus carinatum resulting in sunken and pigeon chests, respectively. A lack of understanding of the ultrastructural and molecular biology of costal cartilage is a major confounder in predicting causes and outcomes of these disorders. This study analyzed the structure of marginal human costal cartilage (ribs 6-10) through scanning electron and atomic force microscopes and identified the presence of straw-like structures running longitudinally. We also demonstrated that chondrocytes tend to occur singly or as doublets and that centrally located cells produce high levels of aggrecan compared with more peripherally located cells measured using immunohistochemistry. Gene expression from mRNA extracted from cartilage showed high levels of decorin expression, likely associated with the large, complex tubular structures running through this cartilage type. COL2A1, ACAN, and TIMP1 also showed higher levels of expression compared with ACTB. Analysis of gene expression ratios demonstrate that costal cartilage is under differentiated compared with published ratios for articular cartilage, likely due to the vastly different biomechanical environments of each cartilage type. Further studies need to establish whether findings described here from the costal margins are significantly different than the cartilage of the "true ribs" and how these values change with age.
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Affiliation(s)
- M W Stacey
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
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