In situ monitoring of mechanical properties during photopolymerization with particle tracking microrheology

Polymer ◽  
2006 ◽  
Vol 47 (7) ◽  
pp. 2263-2268 ◽  
Author(s):  
Ryan P. Slopek ◽  
Haris K. McKinley ◽  
Clifford L. Henderson ◽  
Victor Breedveld
Keyword(s):  
Mechanical Properties ◽  
Particle Tracking ◽  
In Situ Monitoring ◽  
Particle Tracking Microrheology

scholarly journals Measuring the mechanical properties of apoptotic cells using particle tracking microrheology

2021 ◽  
Author(s):  
Ahmed El Kaffas
Keyword(s):  
Mechanical Properties ◽  
Particle Tracking ◽  
Numerical Models ◽  
Soft Materials ◽  
Point Particle ◽  
High Frequency Ultrasound ◽  
Particle Tracking Microrheology ◽  
Viscous Modulus ◽  
Pc3 Cells ◽  
Frequency Ultrasound

Numerical models developed to study high frequency ultrasound scattering during apoptosis require knowledge of mechanical properties of cells. Particle Tracking Microrheology (PTM) is a technique for studying the mechanical properties of soft materials. By tracking the Brownian movement of particles embedded in a material, its mechanical properties can be extracted. In this thesis, PTM is used to measure the relative changes in the viscoelasticity of apoptotic PC3 cells. PTM was first validated in purely viscous and viscoelastic phantoms. It was found to work well in viscous phantoms, but was limited to only measuring relative changes of the viscoelasticity of viscoelastic materials. After validation, PTM measurements in cells showed that the elastic and viscous modulus increased by over 50 Pa and 20 Pa respectively over the course of the treatment. Preliminary development of another technique known as Two-Point Particle Tracking Microrheology (TPM) is also presented in this thesis.

scholarly journals Measuring the mechanical properties of apoptotic cells using particle tracking microrheology

2021 ◽  
Author(s):  
Ahmed El Kaffas
Keyword(s):  
Mechanical Properties ◽  
Particle Tracking ◽  
Numerical Models ◽  
Soft Materials ◽  
Point Particle ◽  
High Frequency Ultrasound ◽  
Particle Tracking Microrheology ◽  
Viscous Modulus ◽  
Pc3 Cells ◽  
Frequency Ultrasound

Numerical models developed to study high frequency ultrasound scattering during apoptosis require knowledge of mechanical properties of cells. Particle Tracking Microrheology (PTM) is a technique for studying the mechanical properties of soft materials. By tracking the Brownian movement of particles embedded in a material, its mechanical properties can be extracted. In this thesis, PTM is used to measure the relative changes in the viscoelasticity of apoptotic PC3 cells. PTM was first validated in purely viscous and viscoelastic phantoms. It was found to work well in viscous phantoms, but was limited to only measuring relative changes of the viscoelasticity of viscoelastic materials. After validation, PTM measurements in cells showed that the elastic and viscous modulus increased by over 50 Pa and 20 Pa respectively over the course of the treatment. Preliminary development of another technique known as Two-Point Particle Tracking Microrheology (TPM) is also presented in this thesis.

Lubricin Interaction With Hyaluronate Promotes Interchain Association Leading to Network Formation

2005 ◽  
Author(s):  
J. R. Torres ◽  
G. D. Jay ◽  
M. L. Warman ◽  
R. M. Laxer ◽  
M. Laderer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Synovial Fluid ◽  
Particle Tracking ◽  
Network Formation ◽  
Molecular Layering ◽  
Cartilage Surface ◽  
Particle Tracking Microrheology ◽  
Boundary Lubricant ◽  
Multiple Particle Tracking ◽  
Multiple Particle

The present work is the first instance where a novel multiple-particle tracking microrheology technique has been applied to study molecular interactions of clinical significance. Herein we describe the molecular changes due to lubricin-hyaluronate interaction and their effect on mechanical properties of synovial fluid. Along with bulk rheology studies it was found that lubricin, a boundary lubricant, increases the HA network formation conducive to the enhanced molecular layering of HA under stress which results in increased shear thinning. This interaction may also allow HA molecules to bind to the cartilage surface, providing boundary lubrication, by virtue of its interaction with lubricin.

Integrated Multi-Sensor Tribo-SPM Nano+Micro Tribo-Metrology

2005 ◽  
Author(s):  
Norm Gitis ◽  
Antanas Daugela ◽  
Jun Xiao ◽  
Michael Vinogradov
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Optical Microscope ◽  
In Situ Monitoring ◽  
Nano Indentation ◽  
Solid Thin Films

A novel quantitative nano+micro tribometer with integrated AFM and optical microscope has been utilized to characterize tribological and mechanical properties of liquid and solid thin films and coatings, with in-situ monitoring their changes during micro and nano indentation, scratching, reciprocating, rotating and other tribology tests.

scholarly journals In situ measurement of localization error in particle tracking microrheology

2018 ◽  
Vol 57 (12) ◽  
pp. 793-800 ◽  
Author(s):  
Lilian Lam Josephson ◽  
James W. Swan ◽  
Eric M. Furst
Keyword(s):  
Particle Tracking ◽  
In Situ Measurement ◽  
Localization Error ◽  
Particle Tracking Microrheology

scholarly journals In situ measurement of ECM rheology and microheterogeneity in embedded and overlaid 3D pancreatic tumor stroma co-cultures via passive particle tracking

2017 ◽  
Vol 10 (06) ◽  
pp. 1742003 ◽  
Author(s):  
Dustin P. Jones ◽  
William Hanna ◽  
Gwendolyn M. Cramer ◽  
Jonathan P. Celli
Keyword(s):  
Mechanical Properties ◽  
Tumor Growth ◽  
Particle Tracking ◽  
Cancer Biology ◽  
Three Dimensional ◽  
Tumor Stroma ◽  
Physical Force ◽  
Culture Models

Tumor growth is regulated by a diverse set of extracellular influences, including paracrine crosstalk with stromal partners, and biophysical interactions with surrounding cells and tissues.Studies elucidating the role of physical force and the mechanical properties of the extracellular matrix (ECM) itself as regulators of tumor growth and invasion have been greatly catalyzed by the use of in vitro three-dimensional (3D) tumor models. These systems provide the ability to systematically isolate, manipulate, and evaluate impact of stromal components and extracellular mechanics in a platform that is both conducive to imaging and biologically relevant. However, recognizing that mechanoregulatory crosstalk is bi-directional and fully utilizing these models requires complementary methods for in situ measurements of the local mechanical environment. Here, in 3D tumor/fibroblast co-culture models of pancreatic cancer, a disease characterized by its prominent stromal involvement, we evaluate the use of particle-tracking microrheology to probe dynamic mechanical changes. Using videos of fluorescently labeled polystyrene microspheres embedded in collagen I ECM, we measure spatiotemporal changes in the Brownian motion of probes to report local ECM shear modulus and microheterogeneity. This approach reveals stiffening of collagen in fibroblast co-cultures relative to cultures with cancer cells only, which exhibit degraded ECM with heterogeneous microstructure. We further show that these effects are dependent on culture geometry with contrasting behavior for embedded and overlay cultures. In addition to potential application to screening stroma-targeted therapeutics, this work also provides insight into how the composition and plating geometry impact the mechanical properties of 3D cell cultures that are increasingly widely used in cancer biology.

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