Name: mechanical testing of mouse carotid arteries: from newborn to adult
Uploaded: 2012-02-23T12:00:00
Description: Watch this Scientific Journal Video about Mechanical Testing of Mouse Carotid Arteries: from Newborn to Adult at JoVE.com

This work was funded, in part, by NIH grants HL087653 and HL105314. Some of the methods described in this work were developed in the laboratory of Dr. Robert Mecham at the Washington University School of Medicine.

1. Pressure myograph set-up
<ol>
	<li>Summarized from the manufacturer instructions (Danish Myotechnology). A schematic of the complete system with optional accessories is shown in Figure 1.</li>
	<li>Turn on the air tank and myograph control boxes and start the MyoView software (Danish Myotechnology). In the software, load the appropriate diameter calibration file, inflation protocol file and name the file for saving data for the first protocol. Recommended inflation protocols for each age are given in Table 1.</li>
	...

<ol>
	<li>Dobrin, P. B., Sumpio, B. E., Sidawy, A. N., DePalma, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+3:+Physiology+and+Pathophysiology+of+Blood+Vessels.">Chapter 3: Physiology and Pathophysiology of Blood Vessels.</a> The Basic Science of Vascular Disease. , 69-105 (1997).</li><li>Wagenseil, J. E., Mecham, R. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+extracellular+matrix+and+arterial+mechanics.">Vascular extracellular matrix and arterial mechanics.</a> Physiol. Rev. 89 (3), 957-989 (2009).</li><li>Le, V. P., Knutsen, R. H., Mecham, R. P., Wagenseil, J. 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Physiol. 292 (6), H2754-H2763 (2007).</li><li>Rezakhaniha, R., Fonck, E., Genoud, C., Stergiopulos, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+elastin+anisotropy+in+structural+strain+energy+functions+of+arterial+tissue.">Role of elastin anisotropy in structural strain energy functions of arterial tissue.</a> Biomech. Model Mechanobiol. 10 (4), 599-611 (2011).</li><li>Eberth, J. F., Taucer, A. I., Wilson, E., Humphrey, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanics+of+carotid+arteries+in+a+mouse+model+of+Marfan+Syndrome.">Mechanics of carotid arteries in a mouse model of Marfan Syndrome.</a> Ann. Biomed. Eng. 37 (6), 1093-1104 (2009).</li><li>Wan, W., Yanagisawa, H., Gleason, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+and+microstructural+properties+of+common+carotid+arteries+from+fibulin-5+null+mice.">Biomechanical and microstructural properties of common carotid arteries from fibulin-5 null mice.</a> Ann. Biomed. Eng. 38 (12), 3605-3617 (2010).</li><li>Faury, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relation+between+outer+and+luminal+diameter+in+cannulated+arteries.">Relation between outer and luminal diameter in cannulated arteries.</a> Am. J. Physiol. 277 (5 Pt. 2), H1745-H1753 (1999).</li><li>Sonveaux, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endothelin-1+is+a+critical+mediator+of+myogenic+tone+in+tumor+arterioles:+implications+for+cancer+treatment.">Endothelin-1 is a critical mediator of myogenic tone in tumor arterioles: implications for cancer treatment.</a> Cancer Res. 64 (9), 3209-3214 (2004).</li><li>Mulcahy, C., Amin, M., Wagenseil, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Creation+of+a+finite+element+model+of+a+mouse+artery+to+examine+circumferential+stress+distribution.">Creation of a finite element model of a mouse artery to examine circumferential stress distribution.</a> Biomedical Engineering Society Annual Meeting. , (2010).</li></ol>

The protocol presented here provides a straightforward and repeatable method for characterizing the passive mechanical behavior of mouse carotid arteries. Although smooth muscle cells and endothelial cells are critical to the function of smaller, muscular arteries and capillaries, they do not contribute significantly to the mechanical behavior of large elastic arteries. Poisoning the cells with KCN has no significant effect on the pressure-diameter behavior of mouse carotid arteries17. Passive mechanical chara...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent/equipment</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Air tank and regulator</td>
 <td>Airgas Mid America</td>
 <td>UN3156</td>
 <td>For pressurizing myograph</td>
 </tr>
 <tr>
 <td>Pressure myograph and software </td>
 <td>Danish Myotechnology</td>
 <td>110P, MyoView</td>
 <td>With custom cannulae (Figure 2)</td>
 </tr>
 <tr>
 <td>Inverted microscope, 5x lens and camera</td>
 <td>Zeiss</td>
 <td>Axiovert 40C</td>
 <td>For tracking artery diameter</td>
 </tr>
 <tr>
 <td>Physiological saline solution (PSS)</td>
 <td>Chemicals from Sigma</td>
 <td></td>
 <td>Recipe and details in Table 2</td>
 </tr>
 <tr>
 <td>Surgical tape</td>
 <td>Various suppliers</td>
 <td></td>
 <td>For securing the mouse during dissection</td>
 </tr>
 <tr>
 <td>Dissection board</td>
 <td>Fisher Scientific</td>
 <td>09-002-24A</td>
 <td>For securing mouse during dissection</td>
 </tr>
 <tr>
 <td>Dissecting microscope with camera</td>
 <td>Zeiss</td>
 <td>Stemi 
 2000-C</td>
 <td>For arterial dissection and mounting </td>
 </tr>
 <tr>
 <td>Dissecting scissors</td>
 <td>Fine Science Tools</td>
 <td>14058-11</td>
 <td>For cutting skin and opening the chest</td>
 </tr>
 <tr>
 <td>Fine tweezers (2)</td>
 <td>Fine Science Tools</td>
 <td>11200-14</td>
 <td>For grasping artery ends</td>
 </tr>
 <tr>
 <td>Curved forceps</td>
 <td>Fine Science Tools</td>
 <td>11274-20</td>
 <td>For clearing tissue and exposing carotid arteries</td>
 </tr>
 <tr>
 <td>Micro-scissors</td>
 <td>Fine Science Tools</td>
 <td>15005-08</td>
 <td>For precise cutting of arteries</td>
 </tr>
 <tr>
 <td>7-0 and 10-0 silk suture</td>
 <td>Various suppliers</td>
 <td></td>
 <td>For estimating length and fastening arteries on cannulae</td>
 </tr>
 <tr>
 <td>Digital calipers</td>
 <td>Fisher Scientific</td>
 <td>806-93-111</td>
 <td>For measuring suture length and checking artery length</td>
 </tr>
 <tr>
 <td>Disposable scalpel</td>
 <td>Feather</td>
 <td>No. 15</td>
 <td>For cutting artery rings</td>
 </tr>
 <tr>
 <td>Activated charcoal</td>
 <td>Sigma</td>
 <td>C4386-500G</td>
 <td>For marking cut locations on vessels</td>
 </tr>
 <tr>
 <td>18G Needle</td>
 <td>Beckton-Dickinson</td>
 <td>305136</td>
 <td>For applying activated charcoal to vessels, clearing blood and filling myograph tubing </td>
 </tr>
 <tr>
 <td>20 mL syringe</td>
 <td>Various suppliers</td>
 <td></td>
 <td>For clearing blood and filling myograph tubing</td>
 </tr>
 <tr>
 <td>Petri dish</td>
 <td>Fisher Scientific</td>
 <td>08-757-13B</td>
 <td>For inserting vessels after dissection and testing to take pictures</td>
 </tr>
 <tr>
 <td>Microfuge tube</td>
 <td>Fisher Scientific</td>
 <td>02-682-550</td>
 <td>For storing vessels before testing</td>
 </tr>
 <tr>
 <td>Fine wire</td>
 <td>California Fine Wire Company</td>
 <td>100192</td>
 <td>For clearing clogged cannula</td>
 </tr>
 <tr>
 <td>ImageJ software</td>
 <td>National Health Institute</td>
 <td>www. rsbweb.nih.gov/ij</td>
 <td>Open-source image processing program developed by NIH</td>
 </tr>
 <tr>
 <td>Matlab software</td>
 <td>Mathworks</td>
 <td></td>
 <td>Useful for analyzing data and fitting constitutive equations</td>
 </tr>
 </tbody>
 </table>

mechanical testing of mouse carotid arteries: from newborn to adult

The large conducting arteries in vertebrates are composed of a specialized extracellular matrix designed to provide pulse dampening and reduce the work performed by the heart. The mix of matrix proteins determines the passive mechanical properties of the arterial wall1. When the matrix proteins are altered in development, aging, disease or injury, the arterial wall remodels, changing the mechanical properties and leading to subsequent cardiac adaptation2. In normal development, the remodeling leads to a functional cardiac and cardiovascular system optimized for the needs of the adult organism. In disease, the remodeling often leads to a negative feedback cycle that can cause cardiac failure and death. By quantifying passive arterial mechanical properties in development and disease, we can begin to understand the normal remodeling process to recreate it in tissue engineering and the pathological remodeling process to test disease treatments.
	Mice are useful models for studying passive arterial mechanics in development and disease. They have a relatively short lifespan (mature adults by 3 months and aged adults by 2 years), so developmental3 and aging studies4 can be carried out over a limited time course. The advances in mouse genetics provide numerous genotypes and phenotypes to study changes in arterial mechanics with disease progression5 and disease treatment6. Mice can also be manipulated experimentally to study the effects of changes in hemodynamic parameters on the arterial remodeling process7. One drawback of the mouse model, especially for examining young ages, is the size of the arteries. 
	We describe a method for passive mechanical testing of carotid arteries from mice aged 3 days to adult (approximately 90 days). We adapt a commercial myograph system to mount the arteries and perform multiple pressure or axial stretch protocols on each specimen. We discuss suitable protocols for each age, the necessary measurements and provide example data. We also include data analysis strategies for rigorous mechanical characterization of the arteries.

Watch this Scientific Journal Video about Mechanical Testing of Mouse Carotid Arteries: from Newborn to Adult at JoVE.com

Mechanical Testing of Mouse Carotid Arteries: from Newborn to Adult

Passive mechanical testing of mouse carotid arteries is described, with special consideration for adapting to different specimen ages. The procedures include determining the in vivo length of the artery, mounting it in a pressure myograph, recording data, measuring the unloaded dimensions and analyzing the resulting data.

The large conducting arteries in vertebrates are composed of a specialized extracellular matrix designed to provide pulse dampening and reduce the work ...

mechanical-testing-of-mouse-carotid-arteries-from-newborn-to-adult

Research

JoVE Journal

Bioengineering

Stress-induced Antibiotic Susceptibility Testing on a Chip

We have developed a rapid microfluidic method for antibiotic susceptibility testing in a stress-based environment. Fluid is passed at high speeds over bacteria immobilized on the bottom of a microfluidic channel. In the presence of stress and antibiotic, susceptible strains of bacteria die rapidly. However, resistant bacteria survive these stressful conditions. The hypothesis behind this method is new: stress activation of biochemical pathways, which are targets of antibiotics, can accelerate antibiotic susceptibility testing. As compared to standard antibiotic susceptibility testing methods, the rate-limiting step -&#160;bacterial growth -&#160;is omitted during antibiotic application. The technical implementation of the method is in a combination of standard techniques and innovative approaches. The standard parts of the method include bacterial culture protocols, defining microfluidic channels in polydimethylsiloxane&#160;(PDMS), cell viability monitoring with fluorescence, and batch image processing for bacteria counting. Innovative parts of the method are in the use of culture media flow for mechanical stress application, use of enzymes to damage but not kill the bacteria, and use of microarray substrates for bacterial attachment. The developed platform can be used in antibiotic and nonantibiotic related drug development and testing. As compared to the standard bacterial suspension experiments, the effect of the drug can be turned on and off repeatedly over controlled time periods. Repetitive observation of the same bacterial population is possible over the course of the same experiment.

We have developed a microfluidic platform for rapid antibiotic susceptibility testing. Fluid is passed at high speeds over bacteria immobilized on the bottom of a microfluidic channel. In the presence of stress and antibiotic, susceptible strains of bacteria die rapidly. However, resistant bacteria can survive these stressful conditions.

We have developed a rapid microfluidic method for antibiotic susceptibility testing in a stress-based environment. Fluid is passed at high speeds over ...

An Improved Mechanical Testing Method to Assess Bone-implant Anchorage

Recent advances in material science have led to a substantial increase in the topographical complexity of implant surfaces, both on a micro- and a nano-scale. As such, traditional methods of describing implant surfaces -&#160;namely numerical determinants of surface roughness -&#160;are inadequate for predicting in vivo performance. Biomechanical testing provides an accurate and comparative platform to analyze the performance of biomaterial surfaces. An improved mechanical testing method to test the anchorage of bone to candidate implant surfaces is presented. The method is applicable to both early and later stages of healing and can be employed for any range of chemically or mechanically modified surfaces -&#160;but not smooth surfaces. Custom rectangular implants are placed bilaterally in the distal femora of male Wistar rats and collected with the surrounding bone. Test specimens are prepared and potted using a novel breakaway mold and the disruption test is conducted using a mechanical testing machine. This method allows for alignment of the disruption force exactly perpendicular, or parallel, to the plane of the implant surface, and provides an accurate and reproducible means for isolating an exact peri-implant region for testing.

An improved method to mechanically test bone anchorage to candidate implant surfaces is presented. This method allows for alignment of the disruption force exactly perpendicular, or parallel, to the plane of the implant surface, and provides an accurate means to direct the disruption forces to an exact peri-implant region.

Recent advances in material science have led to a substantial increase in the topographical complexity of implant surfaces, both on a micro- and a ...

A Method to Estimate Cadaveric Femur Cortical Strains During Fracture Testing Using Digital Image Correlation

This protocol describes the method using digital image correlation to estimate cortical strain from high speed video images of the cadaveric femoral surface obtained from mechanical testing. This optical method requires a texture of many contrasting fiduciary marks on a solid white background for accurate tracking of surface deformation as loading is applied to the specimen. Immediately prior to testing, the surface of interest in the camera view is painted with a water-based white primer and allowed to dry for several minutes. Then, a black paint is speckled carefully over the white background with special consideration for the even size and shape of the droplets. Illumination is carefully designed and set such that there is optimal contrast of these marks while minimizing reflections through the use of filters. Images were obtained through high speed video capture at up to 12,000 frames/s. The key images prior to and including the fracture event are extracted and deformations are estimated between successive frames in carefully sized interrogation windows over a specified region of interest. These deformations are then used to compute surface strain temporally during the fracture test. The strain data is very useful for identifying fracture initiation within the femur, and for eventual validation of proximal femur fracture strength models derived from Quantitative Computed Tomography-based Finite Element Analysis (QCT/FEA).

In this protocol, the femur surface strains are estimated during fracture testing using the digital image correlation technique. The novelty of the method involves application of a high-contrast stochastic speckle pattern on the femur surface, carefully specified illumination, high speed video capture, and digital image correlation analysis for strain calculations.

This protocol describes the method using digital image correlation to estimate cortical strain from high speed video images of the cadaveric femoral ...

A Performance-testing Platform for a Conduction Micropump with an FR-4 Copper-clad Electrode Plate

Here, a conduction micropump with symmetric planar electrode pairs prepared on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) is fabricated. It is used to investigate the influence of chamber dimensions on the performance of a conduction micropump and to determine the reliability of the conduction pump when acetone is used as the working fluid. A testing platform is set up to evaluate conduction micropump performance under different conditions. When the chamber height is 0.2 mm, the pump pressure reaches its peak value.

This paper presents a protocol for the fabrication of a conduction micropump using symmetric planar electrodes on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) to test the influence of chamber dimensions on the performance of a conduction micropump.

Here, a conduction micropump with symmetric planar electrode pairs prepared on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) is ...

A Millimeter Scale Flexural Testing System for Measuring the Mechanical Properties of Marine Sponge Spicules

Many load bearing biological structures (LBBSs)&#8212;such as feather rachises and spicules&#8212;are small (&#60;1 mm) but not microscopic. Measuring the flexural behavior of these LBBSs is important for understanding the origins of their remarkable mechanical functions.
We describe a protocol for performing three-point bending tests using a custom-built mechanical testing device that can measure forces ranging from 10-5 to 101 N and displacements ranging from 10-7 to 10-2 m. The primary advantage of this mechanical testing device is that the force and displacement capacities can be easily adjusted for different LBBSs. The device&#39;s operating principle is similar to that of an atomic force microscope. Namely, force is applied to the LBBS by a load point that is attached to the end of a cantilever. The load point displacement is measured by a fiber optic displacement sensor and converted into a force using the measured cantilever stiffness. The device&#39;s force range can be adjusted by using cantilevers of different stiffnesses.
The device&#39;s capabilities are demonstrated by performing three-point bending tests on the skeletal elements of the marine sponge Euplectella aspergillum. The skeletal elements&#8212;known as spicules&#8212;are silica fibers that are approximately 50 &#181;m in diameter. We describe the procedures for calibrating the mechanical testing device, mounting the spicules on a three-point bending fixture with a &#8776;1.3 mm span, and performing a bending test. The force applied to the spicule and its deflection at the location of the applied force are measured.

We present a protocol for performing three-point bending tests on sub-millimeter scale fibers using a custom-built mechanical testing device. The device can measure forces ranging from 20 &#181;N up to 10 N and can therefore accommodate a variety of fiber sizes.

Many load bearing biological structures (LBBSs)&#8212;such as feather rachises and spicules&#8212;are small (&#60;1 mm) but not microscopic. Measuring the ...

Environmental Dynamic Mechanical Analysis to Predict the Softening Behavior of Neural Implants

When using dynamically softening substrates for neural implants, it is important to have a reliable in vitro method to characterize the softening behavior of these materials. In the past, it has not been possible to satisfactorily measure the softening of thin films under conditions mimicking body environment without substantial effort. This publication presents a new and simple method that allows dynamic mechanical analysis (DMA) of polymers in solutions, such as phosphate buffered saline (PBS), at relevant temperatures. The use of environmental DMA allows measurement of the softening effects of polymers due to plasticization in various media and temperatures, which therefore allows a prediction of the materials behavior under in vivo conditions.

To allow reliable predictions of the softening of polymeric substrates for neural implants in an in vivo environment, it is important to have a reliable in vitro method. Here, the use of dynamic mechanical analysis in phosphate buffered saline at body temperature is presented.

When using dynamically softening substrates for neural implants, it is important to have a reliable in vitro method to characterize the softening behavior ...

The Quantification of Injectability by Mechanical Testing

Injectable biomaterials are becoming increasingly popular for the minimally invasive delivery of drugs and cells. These materials are typically more viscous than traditional aqueous injections and may be semi-solid, therefore, their injectability cannot be assumed. This protocol describes a method to objectively assess the injectability of these materials using a standard mechanical tester. The syringe plunger is compressed by the crosshead at a set rate, and the force is measured. The maximum or plateau force value can then be used for comparison between samples, or to an absolute force limit. This protocol can be used with any material, and any syringe and needle size or geometry. The results obtained may be used to make decisions about formulations, syringe and needle sizes early in the translational process. Further, the effects of altering formulations on injectability may be quantified, and the optimum time to inject temporally changing materials determined. This method is also suitable as a reproducible way to examine the effects of injection on a material, to study phenomena such as self-healing and filter pressing or study the effects of injection on cells. This protocol is faster and more directly applicable to injectability than rotational rheology, and requires minimal post processing to obtain key values for direct comparisons.

Presented here is a protocol for quantitatively evaluating the injectability of a material through a syringe-needle system using a standard mechanical testing rig.

Injectable biomaterials are becoming increasingly popular for the minimally invasive delivery of drugs and cells. These materials are typically more ...

Single-Cell Optical Action Potential Measurement in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Conventional intracellular microelectrode techniques to quantify cardiomyocyte electrophysiology are extremely complex, labor intensive, and typically carried out in low throughput. Rapid and ongoing expansion of induced pluripotent stem cell (iPSC) technology presents a new standard in cardiovascular research and alternate methods are now necessary to increase throughput of electrophysiological data at a single cell level. VF2.1Cl is a recently derived voltage sensitive dye which provides a rapid single channel, high magnitude response to fluctuations in membrane potential. It possesses kinetics superior to those of other existing voltage indicators and makes available functional data equivalent to that of traditional microelectrode techniques. Here, we demonstrate simplified, non-invasive action potential characterization in externally paced human iPSC derived cardiomyocytes using a modular and highly affordable photometry system.

Here we describe optical acquisition and characterization of action potentials from induced pluripotent stem cell derived cardiomyocytes using a high-speed modular photometry system.

Conventional intracellular microelectrode techniques to quantify cardiomyocyte electrophysiology are extremely complex, labor intensive, and typically ...

Fibroblast Derived Human Engineered Connective Tissue for Screening Applications

Fibroblasts are phenotypically highly dynamic cells, which quickly transdifferentiate into myofibroblasts in response to biochemical and biomechanical stimuli. The current understanding of fibrotic processes, including cardiac fibrosis, remains poor, which hampers the development of new anti-fibrotic therapies. Controllable and reliable human model systems are crucial for a better understanding of fibrosis pathology. This is a highly reproducible and scalable protocol to generate engineered connective tissues (ECT) in a 48-well casting plate to facilitate studies of fibroblasts and the pathophysiology of fibrotic tissue in a 3-dimensional (3D) environment. ECT are generated around the poles with tunable stiffness, allowing for studies under a defined biomechanical load. Under the defined loading conditions, phenotypic adaptations controlled by cell-matrix interactions can be studied. Parallel testing is feasible in the 48-well format with the opportunity for the time-course analysis of multiple parameters, such as tissue compaction and contraction against the load. From these parameters, biomechanical properties such as tissue stiffness and elasticity can be studied.

Presented here is a protocol to generate engineered connective tissues for a parallel culture of 48 tissues in a multi-well plate with double poles, suitable for mechanistic studies, disease modeling, and screening applications. The protocol is compatible with fibroblasts from different organs and species and is exemplified here with human primary cardiac fibroblasts.

Fibroblasts are phenotypically highly dynamic cells, which quickly transdifferentiate into myofibroblasts in response to biochemical and biomechanical ...

A Friction Testing-Bioreactor Device for Study of Synovial Joint Biomechanics, Mechanobiology, and Physical Regulation

In primary osteoarthritis (OA), normal 'wear and tear' associated with aging inhibits the ability of cartilage to sustain its load-bearing and lubrication functions, fostering a deleterious physical environment. The frictional interactions of articular cartilage and synovium may influence joint homeostasis through tissue level wear and cellular mechanotransduction. To study these mechanical and mechanobiological processes, a device capable of replicating the motion of the joint is described. The friction testing device controls the delivery of reciprocal translating motion and normal load to two contacting biological counterfaces. This study adopts a synovium-on-cartilage configuration, and friction coefficient measurements are presented for tests performed in a phosphate-buffered saline (PBS) or synovial fluid (SF) bath. The testing was performed for a range of contact stresses, highlighting the lubricating properties of SF under high loads. This friction testing device can be used as a biomimetic bioreactor for studying the physical regulation of living joint tissues in response to applied physiologic loading associated with diarthrodial joint articulation.

The present protocol describes a friction testing device that applies simultaneous reciprocal sliding and normal load to two contacting biological counterfaces.

In primary osteoarthritis (OA), normal 'wear and tear' associated with aging inhibits the ability of cartilage to sustain its load-bearing and lubrication ...