Assessment of viscous and elastic properties of sub-wavelength layered soft tissues using shear wave spectroscopy: Theoretical framework and in vitro experimental validation

Shear Wave Elastography (SWE) is a non-invasive diagnostic imaging technique, that maps the elastic properties of tissues. Nowadays this modality develops increasingly in medicine across its disciplines and opens a new era of high-quality ultrasound examination because it increases the specificity and thus improves diagnostic assurance. This method is similar to manual palpation, shows elastic properties of biological tissues and provides a kind of reconstruction of the internal structure of soft tissues based on measurement of the response of tissue compression. Results: This method is already used routinely in the detection and diagnosis of breast cancer and thyroid cancer, prostate cancer, in hepatology, cardiology, view of the carotid arteries and lymphatic nodules. Standards of elasticity values for human tissues such as the mammary gland, liver, prostate or thyroid gland are progressively being created across the medical fields. Finally, the article examines its unquestioned benefit in ophthalmology. In ophthalmology, it already appears as an up-and-coming method in diagnostics and in evaluating the changes in oculomotor muscles and orbital tissues in patients with endocrine orbitopathy. Conclusion: Shear wave elastography offers three main innovations: the quantitative aspect, dimensional resolution, and real-time imaging ability. Determination of the utilization rate of this method and its inclusion into the diagnostics of endocrine orbitopathy is still a question and the subject of presently conducted clinical studies.

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Intra- and inter-observer variation and accuracy using different shear wave elastography methods to assess circumscribed objects – a phantom study.

Medical Ultrasonography ◽

10.11152/mu-1080 ◽

2017 ◽

Vol 19 (4) ◽

pp. 357 ◽

Cited By ~ 4

Author(s):

Gregor Seliger ◽

Katharina Chaoui ◽

Christian Kunze ◽

Yasmina Dridi ◽

Klaus-Vitold Jenderka ◽

...

Keyword(s):

Shear Wave ◽

Elastic Properties ◽

Measurement Techniques ◽

Intraclass Correlation ◽

Shear Wave Elastography ◽

Observer Variation ◽

Significant Difference ◽

Clinical Interest ◽

Observational Errors

Aims: The elastic properties of circumscribed tissues (e.g., tendons, lymph nodes, prostates, brain tumors) are of considerable clinical interest. The purpose of this study was thus to compare the Intra-/Inter-observer variation and accuracy in vitro of point shear wave elastography (pSWE) with that of 2D-SWE and to assess 2D-SWE’s precision with variable ROI (vROI) incircumscribed objects.Material and methods: Round targets (Elasticity QA Phantom Model 049) were examined for varying degrees of stiffness (8, 14, 45, and 80 kPa) and diameters (20/10 mm). Three ultrasound systems and four probes were applied (pSWE: Acuson/S3000 9L4/4C1 and Epiq7 C51, 2D-SWE: Aplio/500 PVT375BT). Three different ROIs were used, namely fixed ROI (fROI) and variable ROI: rectangular-best-fitted ROI, and round-best-fitted ROI. Each measurement was performed twice by four observers.Results: A total of 3,604 measurements were conducted. The intra-observer variation of 2D-SWE measurements indicated better agreement (Intraclass Correlation Coefficient (ICC) = 0.971; 95% CI=[0.945; 0.985]), than for the pSWE measurements (ICC = 0.872; 95% CI=[0.794; 0.92]). With both methods, the shear wave elastography applied showed low inter-observer variation: ICC = 0.980; 95% CI=[0.970; 0.987]. However, a significant difference was observed between fROI (pSWE) and vROI (2D-SWE) on circumscribed objects in terms of accuracy. The lowest degree of observationerror was detected in situations where the ROI was not “best fitted”, but placed within the target of 3mm from the border (target diameter: 20mm; mean relative error = 0.15).Conclusions: When estimating the elastic properties of circumscribed tissues, the different measurement techniques performed by commercial shear wave elastography systems reveal a strong susceptibility for observational errors, depending upon the fixed vs. variable ROI of the pSWE vs. 2D-SWE technique.

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Biological and biomedical applications of collagenous biomaterials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161849 ◽

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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3D Culture Modelling: An Emerging Approach for Translational Cancer Research in Sarcomas

Current Medicinal Chemistry ◽

10.2174/0929867326666191212162102 ◽

2020 ◽

Vol 27 (29) ◽

pp. 4778-4788 ◽

Cited By ~ 1

Author(s):

Victoria Heredia-Soto ◽

Andrés Redondo ◽

José Juan Pozo Kreilinger ◽

Virginia Martínez-Marín ◽

Alberto Berjón ◽

...

Keyword(s):

High Throughput Screening ◽

Cancer Biology ◽

Soft Tissues ◽

Three Dimensional ◽

3D Culture ◽

Resistance Mechanisms ◽

In Vitro Models ◽

Tumour Spheroids ◽

Current Therapies

Sarcomas are tumours of mesenchymal origin, which can arise in bone or soft tissues. They are rare but frequently quite aggressive and with a poor outcome. New approaches are needed to characterise these tumours and their resistance mechanisms to current therapies, responsible for tumour recurrence and treatment failure. This review is focused on the potential of three-dimensional (3D) in vitro models, including multicellular tumour spheroids (MCTS) and organoids, and the latest data about their utility for the study on important properties for tumour development. The use of spheroids as a particularly valuable alternative for compound high throughput screening (HTS) in different areas of cancer biology is also discussed, which enables the identification of new therapeutic opportunities in commonly resistant tumours.

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Ultra-strong bio-glue from genetically engineered polypeptides

Nature Communications ◽

10.1038/s41467-021-23117-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Chao Ma ◽

Jing Sun ◽

Bo Li ◽

Yang Feng ◽

Yao Sun ◽

...

Keyword(s):

Soft Tissues ◽

Covalent Bond ◽

Genetically Engineered ◽

Supramolecular Interactions ◽

Molar Ratio ◽

High Adhesion ◽

Strong Adhesion ◽

Order Of Magnitude

AbstractThe development of biomedical glues is an important, yet challenging task as seemingly mutually exclusive properties need to be combined in one material, i.e. strong adhesion and adaption to remodeling processes in healing tissue. Here, we report a biocompatible and biodegradable protein-based adhesive with high adhesion strengths. The maximum strength reaches 16.5 ± 2.2 MPa on hard substrates, which is comparable to that of commercial cyanoacrylate superglue and higher than other protein-based adhesives by at least one order of magnitude. Moreover, the strong adhesion on soft tissues qualifies the adhesive as biomedical glue outperforming some commercial products. Robust mechanical properties are realized without covalent bond formation during the adhesion process. A complex consisting of cationic supercharged polypeptides and anionic aromatic surfactants with lysine to surfactant molar ratio of 1:0.9 is driven by multiple supramolecular interactions enabling such strong adhesion. We demonstrate the glue’s robust performance in vitro and in vivo for cosmetic and hemostasis applications and accelerated wound healing by comparison to surgical wound closures.

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Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽

10.1186/s42836-021-00075-7 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Toni Wendler ◽

Torsten Prietzel ◽

Robert Möbius ◽

Jean-Pierre Fischer ◽

Andreas Roth ◽

...

Keyword(s):

Soft Tissue ◽

Work Experience ◽

Soft Tissues ◽

Force Sensor ◽

Biomechanical Study ◽

Measuring System ◽

Wide Range ◽

Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

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Photodynamic Therapy Combined with Antibiotics or Antifungals against Microorganisms That Cause Skin and Soft Tissue Infections: A Planktonic and Biofilm Approach to Overcome Resistances

Pharmaceuticals ◽

10.3390/ph14070603 ◽

2021 ◽

Vol 14 (7) ◽

pp. 603

Author(s):

Vanesa Pérez-Laguna ◽

Isabel García-Luque ◽

Sofía Ballesta ◽

Antonio Rezusta ◽

Yolanda Gilaberte

Keyword(s):

Photodynamic Therapy ◽

Soft Tissues ◽

Combined Treatment ◽

Resistance Pattern ◽

Antimicrobial Photodynamic Therapy ◽

Antimicrobial Drugs ◽

Bacteria And Fungi ◽

High Level ◽

Selection Of

The present review covers combination approaches of antimicrobial photodynamic therapy (aPDT) plus antibiotics or antifungals to attack bacteria and fungi in vitro (both planktonic and biofilm forms) focused on those microorganisms that cause infections in skin and soft tissues. The combination can prevent failure in the fight against these microorganisms: antimicrobial drugs can increase the susceptibility of microorganisms to aPDT and prevent the possibility of regrowth of those that were not inactivated during the irradiation; meanwhile, aPDT is effective regardless of the resistance pattern of the strain and their use does not contribute to the selection of antimicrobial resistance. Additive or synergistic antimicrobial effects in vitro are evaluated and the best combinations are presented. The use of combined treatment of aPDT with antimicrobials could help overcome the difficulty of fighting high level of resistance microorganisms and, as it is a multi-target approach, it could make the selection of resistant microorganisms more difficult.

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Multifunctional Coatings for Robotic Implanted Device

International Journal of Molecular Sciences ◽

10.3390/ijms20205126 ◽

2019 ◽

Vol 20 (20) ◽

pp. 5126 ◽

Cited By ~ 2

Author(s):

Caterina Cristallini ◽

Serena Danti ◽

Bahareh Azimi ◽

Veronika Tempesti ◽

Claudio Ricci ◽

...

Keyword(s):

Acrylic Acid ◽

Vinyl Alcohol ◽

Soft Tissues ◽

Functional Characterization ◽

Titanium Substrate ◽

Repair Process ◽

Chemical Imaging ◽

In Vitro Cytotoxicity ◽

Poly Vinyl Alcohol

The objective of this study was the preparation and physico-chemical, mechanical, biological, and functional characterization of a multifunctional coating for an innovative, fully implantable device. The multifunctional coating was designed to have three fundamental properties: adhesion to device, close mechanical resemblance to human soft tissues, and control of the inflammatory response and tissue repair process. This aim was fulfilled by preparing a multilayered coating based on three components: a hydrophilic primer to allow device adhesion, a poly(vinyl alcohol) hydrogel layer to provide good mechanical compliance with the human tissue, and a layer of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) fibers. The use of biopolymer fibers offered the potential for a long-term interface able to modulate the release of an anti-inflammatory drug (dexamethasone), thus contrasting acute and chronic inflammation response following device implantation. Two copolymers, poly(vinyl acetate-acrylic acid) and poly(vinyl alcohol-acrylic acid), were synthetized and characterized using thermal analysis (DSC, TGA), Fourier transform infrared spectroscopy (FT-IR chemical imaging), in vitro cell viability, and an adhesion test. The resulting hydrogels were biocompatible, biostable, mechanically compatible with soft tissues, and able to incorporate and release the drug. Finally, the multifunctional coating showed a good adhesion to titanium substrate, no in vitro cytotoxicity, and a prolonged and controlled drug release.

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