A New Apparatus for the in Vitro Testing of the Mechanical Properties of Soft Tissues

1978 ◽  
Vol 7 (4) ◽  
pp. 231-232 ◽  
Author(s):  
R. van Noort ◽  
J. C. Stevens ◽  
M. M. Black
Keyword(s):  
Mechanical Properties ◽  
Soft Tissues ◽  
In Vitro Testing ◽  
New Apparatus

Mechanical Properties of the Epidermis and Stratum Corneum Determined by Submicron Indentation In Vitro

2009 ◽  
Author(s):  
Marion Geerligs ◽  
Lambert C. A. v. Breemen ◽  
Gerrit W. M. Peters ◽  
Paul A. J. Ackermans ◽  
Cees W. J. Oomens ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stratum Corneum ◽  
Mechanical Behavior ◽  
Soft Tissues ◽  
Sensory Nerve ◽  
Complex Nature ◽  
Outer Skin ◽  
Viable Epidermis

The outer skin layers are important drug and vaccine delivery targets in the treatment of diseases. These skin layers possess some important characteristics making them favorable sites for pain-free delivery with minimal damage: a rich population of immunologically sensitive cells as well as the lack of blood vessels and sensory nerve endings [1]. Until today, however, the development of effective cell targeting methods is acquainted with many challenges. A collective shortcoming is a poor understanding of the key mechanical properties of the outer skin layers, e.g. the stratum corneum and epidermis. The anisotropic, dynamic and very complex nature of skin makes it difficult to perform proper mechanical testing as well as to obtain reliable, reproducible data. The stratum corneum is an effective physical barrier of dead cells with a “brick-and-mortar” structure, while the viable epidermis mainly consists of actively migrating keratinocytes constantly undergoing massive morphological and compositional changes. As a consequence, the structure differences among the skin layers lead to significant variations in mechanical properties. Since there is no method available to determine the mechanical behavior of isolated viable epidermis in vivo or in vitro, the mechanical behavior of epidermis and stratum corneum only are investigated here. A commercially available indentation system has been adapted to enable the measurement of these thin soft tissues in an in vitro set up. Combining the outcomes of the two skin layer types leads to an assessment of the contribution of the viable epidermis to the mechanical behavior of skin. To our knowledge, no data have been published yet regarding mechanical bulk properties of (viable) epidermis, while no consistency exists with respect to those of the stratum corneum.

Relating Network Topology to Network Mechanics

2012 ◽  
Author(s):  
Eric M. Christiansen ◽  
Mohammad F. Hadi ◽  
Victor H. Barocas
Keyword(s):  
Mechanical Properties ◽  
Network Topology ◽  
Soft Tissues ◽  
Topological Properties ◽  
Fiber Network ◽  
Fiber Networks ◽  
Protein Fiber ◽  
Network Topologies

Soft tissues are comprised of underlying fiber networks of collagen and other fibrous proteins and biopolymers. Thus, the ability to model the deformation of fiber networks is critical to understanding the mechanics of tissues in vivo and in vitro [1]. Complicating the issue, protein fiber networks are comprised of a range of different topologies that behave differently under load. There is a clear need for a method to derive network parameters that characterize the network and allow for the prediction of their behavior. In this study, we characterized several different random fiber network types based on their intrinsic mechanical and topological properties. Such characterization would improve our ability to select microscale network topologies that match the mechanical properties we observe in healthy and diseased native tissues [2]. It would also improve our ability to discern the outcome of microstructural changes in tissues (such as from remodeling or injury) on their overall mechanics.

scholarly journals 3D Printed Model of Extrahepatic Biliary Ducts for Biliary Stent Testing

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4788
Author(s):  
Joanna Thomas ◽  
Sagar Patel ◽  
Leia Troop ◽  
Robyn Guru ◽  
Nicholas Faist ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Computer Aided Design ◽  
Bile Ducts ◽  
Biliary Stent ◽  
Metal Stents ◽  
In Vitro Testing ◽  
Stent Deployment ◽  
3D Print ◽  
3D Printed

Several inflammatory conditions of the bile ducts cause strictures that prevent the drainage of bile into the gastrointestinal tract. Non-pharmacological treatments to re-establish bile flow include plastic or self-expanding metal stents (SEMs) that are inserted in the bile ducts during endoscopic retrograde cholangiopancreatography (ERCP) procedures. The focus of this study was to 3D print an anatomically accurate model of the extrahepatic bile ducts (EHBDs) with tissue-like mechanical properties to improve in vitro testing of stent prototypes. Following generation of an EHBD model via computer aided design (CAD), we tested the ability of Formlabs SLA 3D printers to precisely print the model with polymers selected based on the desired mechanical properties. We found the printers were reliable in printing the dimensionally accurate EHBD model with candidate polymers. Next, we evaluated the mechanical properties of Formlabs Elastic (FE), Flexible (FF), and Durable (FD) resins pre- and post-exposure to water, saline, or bile acid solution at 37 °C for up to one week. FE possessed the most bile duct-like mechanical properties based on its elastic moduli, percent elongations at break, and changes in mass under all liquid exposure conditions. EHBD models printed in FE sustained no functional damage during biliary stent deployment or when tube connectors were inserted, and provided a high level of visualization of deployed stents. These results demonstrate that our 3D printed EHBD model facilitates more realistic pre-clinical in vitro testing of biliary stent prototypes.

scholarly journals Remote spatially variant debiased profiling of cell and tissue mechanical properties

2021 ◽  
Author(s):  
Jonathan H Mason ◽  
Lu Luo ◽  
Yvonne Reinwald ◽  
Matteo Taffetani ◽  
Amelia Hallas-Potts ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Time Course ◽  
Soft Tissues ◽  
Multiple Scales ◽  
Ground Truth ◽  
Optical Coherence ◽  
Tomography System ◽  
Spatially Variant

The role of the mechanical environment in defining tissue function, development, and growth has been shown to be fundamental. Assessment of the changes in stiffness of tissue matrices at multiple scales has relied mostly on invasive and often specialist equipment such as AFM or mechanical testing devices poorly suited to the cell culture workflow. In this paper, we have developed a novel unbiased passive optical coherence elastography method, exploiting ambient vibrations in the sample that enables real-time noninvasive quantitative profiling of cells and tissues. We demonstrate a robust method that decouples optical scattering and mechanical properties by actively compensating for scattering associated noise bias and reducing variance. The efficiency for the method to retrieve ground truth is validated in silico and in vitro, and exemplified for key applications such as time course mechanical profiling of bone and cartilage spheroids, tissue engineering cancer models, tissue repair models and single cell. Our method is readily implementable with any commercial optical coherence tomography system without any hardware modifications, and thus offers a breakthrough in tissue mechanical assessment for novel online assessment of spatial mechanical properties for organoids, soft tissues and tissue engineering.

Measurement of Mechanical Properties of Soft Tissues In Vitro Under Controlled Tissue Hydration

2012 ◽  
Vol 53 (3) ◽  
pp. 405-414 ◽  
Author(s):  
D. Shahmirzadi ◽  
H. A. Bruck ◽  
A. H. Hsieh
Keyword(s):  
Mechanical Properties ◽  
Soft Tissues ◽  
Tissue Hydration

Artificial Salivas: Present and Future

1987 ◽  
Vol 66 (1_suppl) ◽  
pp. 693-698 ◽  
Author(s):  
M. J. Levine ◽  
A. Aguirre ◽  
M. N. Hatton ◽  
L. A. Tabak
Keyword(s):  
Soft Tissues ◽  
Artificial Saliva ◽  
Modern Technology ◽  
Biologically Active ◽  
Computer Assisted ◽  
In Vitro Testing ◽  
Structural Requirements ◽  
Saliva Substitutes ◽  
Systemic Health

Modern technology has allowed us to understand better the functions of saliva and now provides a rationale for developing: (1) diagnostic reagents for monitoring oral and systemic health status and (2) replacement therapies for individuals with salivary dysfunctions. Several areas of dental research are directed at augmenting or enhancing both the quality and quantity of saliva for individuals with dry mouth. An “intrinsic” approach is being explored which utilizes medications such as pilocarpine and bromhexine to stimulate the salivary glands to produce more saliva. An “extrinsic” approach proposes to use topically applied artificial saliva. Studies in our laboratory have been directed toward developing artificial salivas which incorporate many of the protective features of “native” saliva. An ideal artificial saliva should be “long-lasting”, provide lubrication, inhibit colonization of microflora responsible for dental caries and gingivitis, and coat the oral soft tissues for protection against environmental insult and desiccation. Studies are currently under way to determine the structural requirements of salivary molecules responsible for these protective functions. Composite salivary molecules consisting of multiple biologically active or “functional domains” could then be designed and synthesized based upon primary sequence and conformational analyses, computer-assisted structural predictions, and in vitro testing. These supcrsalivary substances could then be used as saliva substitutes for targeting to selected oral surfaces to promote mineralization, hydration, and/or regulate microbial-mediated disease.

scholarly journals Laser sintering of nano 13-93 glass scaffolds: Microstructure, mechanical properties and bioactivity

2015 ◽  
Vol 47 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Y. Cao ◽  
B. Yang ◽  
C. Gao ◽  
P. Feng ◽  
C. Shuai
Keyword(s):  
Mechanical Properties ◽  
Cell Culture ◽  
Bioactive Glass ◽  
Soft Tissues ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
In Vitro Bioactivity ◽  
Culture Study ◽  
Cell Culture Study

As the only bioactive material that can bond with both hard tissues and soft tissues, bioactive glass has become much important in the field of tissue engineering. 13-93 bioactive glass scaffolds were fabricated via selective laser sintering (SLS). It was focused on the effects of laser sintering on microstructure and mechanical properties of the scaffolds. The experimental results showed that the sintered layer gradually became dense with the laser power increasing and then some defects occurred, such as macroscopic caves. The optimum compressive strength and fracture toughness were 21.43?0.87 MPa and 1.14?0.09 MPa.m1/2, respectively. In vitro bioactivity showed that there was the bone-like apatite layer on the surface of the scaffolds after soaking in simulated body fluid (SBF), which was further evaluated by Fourier transform infrared spectroscopy (FTIR). Moreover, cell culture study showed MG-63 cells adhered and spread well on the scaffolds, and proliferated with increasing time in cell culture. These indicated excellent bioactivity and biocompatibility of nano 13-93 glass scaffolds.

A Review of Apparatus for Investigating the Mechanical Properties of Soft Animal Tissue in Vitro

1977 ◽  
Vol 6 (4) ◽  
pp. 112-119 ◽  
Author(s):  
J C Stevens ◽  
N B Jones
Keyword(s):  
Mechanical Properties ◽  
Skeletal Muscle ◽  
Soft Tissues ◽  
Animal Tissue ◽  
Main Topic ◽  
Design Features ◽  
Uniaxial Testing ◽  
And Performance

This paper contains a review of the systems developed for testing skeletal muscle in vitro and it demonstrates how many of the design features and performance figures obtained are similar even though a range of engineering techniques have been used. The main topic considered is the uniaxial testing of skeletal muscle but it is also shown, by example, that similar ideas have been incorporated into machines for the uniaxial and multi-axial testing of other soft tissues.

Artificial Salivas: Present and Future

1987 ◽  
Vol 66 (2_suppl) ◽  
pp. 693-698 ◽  
Author(s):  
M. J. Levine ◽  
A. Aguirre ◽  
M. N. Hatton ◽  
L. A. Tabak
Keyword(s):  
Soft Tissues ◽  
Artificial Saliva ◽  
Modern Technology ◽  
Biologically Active ◽  
Computer Assisted ◽  
In Vitro Testing ◽  
Structural Requirements ◽  
Saliva Substitutes ◽  
Systemic Health

Modern technology has allowed us to understand better the functions of saliva and now provides a rationale for developing: (1) diagnostic reagents for monitoring oral and systemic health status and (2) replacement therapies for individuals with salivary dysfunctions. Several areas of dental research are directed at augmenting or enhancing both the quality and quantity of saliva for individuals with dry mouth. An “intrinsic” approach is being explored which utilizes medications such as pilocarpine and bromhexine to stimulate the salivary glands to produce more saliva. An “extrinsic” approach proposes to use topically applied artificial saliva. Studies in our laboratory have been directed toward developing artificial salivas which incorporate many of the protective features of “native” saliva. An ideal artificial saliva should be “long-lasting”, provide lubrication, inhibit colonization of microflora responsible for dental caries and gingivitis, and coat the oral soft tissues for protection against environmental insult and desiccation. Studies are currently under way to determine the structural requirements of salivary molecules responsible for these protective functions. Composite salivary molecules consisting of multiple biologically active or “functional domains” could then be designed and synthesized based upon primary sequence and conformational analyses, computer-assisted structural predictions, and in vitro testing. These supersalivary substances could then be used as saliva substitutes for targeting to selected oral surfaces to promote mineralization, hydration, and/or regulate microbial-mediated disease.

Biological and biomedical applications of collagenous biomaterials

1990 ◽  
Vol 48 (3) ◽  
pp. 856-857
Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman
Keyword(s):  
Biomedical Applications ◽  
Soft Tissues ◽  
Collagen Fibers ◽  
Bone Collagen ◽  
Cover Slip ◽  
Fibroblast Migration ◽  
Cellular Expression ◽  
Defect Repair

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.

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