Enhancement of contrast in photoacoustic – fluorescence tomography and cytometry using optical clearing and contrast agents

2021 ◽  
pp. 419-444
Author(s):  
Julijana Cvjetinovic ◽  
Daniil V. Nozdriukhin ◽  
Maksim Mokrousov ◽  
Alexander Novikov ◽  
Marina V. Novoselova ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Fluorescence Tomography ◽  
Optical Clearing

scholarly journals Air-Filled Microbubbles Based on Albumin Functionalized with Gold Nanocages and Zinc Phthalocyanine for Multimodal Imaging

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1161
Author(s):  
Elizaveta A. Maksimova ◽  
Roman A. Barmin ◽  
Polina G. Rudakovskaya ◽  
Olga A. Sindeeva ◽  
Ekaterina S. Prikhozhdenko ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Physicochemical Parameters ◽  
Multimodal Imaging ◽  
Biomedical Applications ◽  
Zinc Phthalocyanine ◽  
Fluorescence Tomography ◽  
Raster Scanning ◽  
Air Core ◽  
Gold Nanocages ◽  
Potential Use

Microbubbles are intravascular contrast agents clinically used in diagnostic sonography, echocardiography, and radiology imaging applications. However, up to date, the idea of creating microbubbles with multiple functionalities (e.g., multimodal imaging, photodynamic therapy) remained a challenge. One possible solution is the modification of bubble shells by introducing specific compounds responsible for such functions. In the present work, air-core microbubbles with the shell consisting of bovine serum albumin, albumin-coated gold nanocages, and zinc phthalocyanine were prepared using the sonication method. Various physicochemical parameters such as stability over time, size, and concentration were investigated to prove the potential use of these microbubbles as contrast agents. This work shows that hybrid microbubbles have all the necessary properties for multimodal imaging (ultrasound, raster-scanning microscopy, and fluorescence tomography), which demonstrate superior characteristics for potential theranostic and related biomedical applications.

scholarly journals A Library of Potential Nanoparticle Contrast Agents for X-Ray Fluorescence Tomography Bioimaging

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yuyang Li ◽  
Kian Shaker ◽  
Jakob C. Larsson ◽  
Carmen Vogt ◽  
Hans M. Hertz ◽  
...  
Keyword(s):  
Contrast Agents ◽  
High Spatial Resolution ◽  
Tumor Imaging ◽  
Small Animal ◽  
Laboratory System ◽  
Fluorescence Tomography ◽  
X Ray ◽  
Tomography System ◽  
Compton Background ◽  
Biological Optimization

Nanoparticles (NPs) have been used as contrast agents for several bioimaging modalities. X-ray fluorescence (XRF) tomography can provide sensitive and quantitative 3D detection of NPs. With spectrally matched NPs as contrast agents, we demonstrated earlier in a laboratory system that XRF tomography could achieve high-spatial-resolution tumor imaging in mice. Here, we present the synthesis, characterization, and evaluation of a library of NPs containing Y, Zr, Nb, Rh, and Ru that have spectrally matched K-shell absorption for the laboratory scale X-ray source. The K-shell emissions of these NPs are spectrally well separated from the X-ray probe and the Compton background, making them suitable for the lab-scale XRF tomography system. Their potential as XRF contrast agents is demonstrated successfully in a small-animal equivalent phantom, confirming the simulation results. The diversity in the NP composition provides a flexible platform for a better design and biological optimization of XRF tomography nanoprobes.

Magnetic resonance contrast agents in optical clearing: Prospects for multimodal tissue imaging

2020 ◽  
Vol 13 (11) ◽  
Author(s):  
Daria K. Tuchina ◽  
Irina G. Meerovich ◽  
Olga A. Sindeeva ◽  
Victoria V. Zherdeva ◽  
Alexander P. Savitsky ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Contrast Agents ◽  
Tissue Imaging ◽  
Optical Clearing ◽  
Magnetic Resonance Contrast ◽  
Resonance Contrast

Effects of Radiographic Contrast Agents on Thrombin Formation and Activity

1998 ◽  
Vol 80 (08) ◽  
pp. 266-272 ◽  
Author(s):  
Andrew Parker ◽  
William Fay
Keyword(s):  
Contrast Agents ◽  
Tissue Factor ◽  
Coronary Angioplasty ◽  
Molecular Mechanisms ◽  
Factor Viia ◽  
Minor Effect ◽  
Ionic Contrast ◽  
Radiographic Contrast ◽  
Inhibition Of Thrombin ◽  
Thrombin Formation

SummaryClinical trials suggest that the risk of thrombosis during coronary angioplasty is lower with ionic contrast agents than with nonionic contrast agents. However, the molecular mechanisms underlying this effect are unknown. This study examined the effects of contrast agents on thrombin formation and its interaction with substrates, inhibitors, and ligands to define potential mechanisms by which contrast agents affect thrombus formation. Two ionic agents, diatrizoate and ioxaglate, and one nonionic agent, ioversol, were studied. Ionic agents inhibited factor X activation by the tissue factor-factor VIIa complex more potently than ioversol (53 ± 3.7, 43.0 ± 1.9, and 26.5 ± 2.4% inhibition by diatrizoate, ioxaglate, and ioversol, respectively, at concentrations of 5%). Ionic contrast agents were potent inhibitors of prothrombinase function, inhibiting thrombin formation by >75% at contrast concentrations of 0.6% (p <0.005). Ioversol inhibited prothrombinase to a significantly lesser extent than ionic agents. Clotting assays suggested that ioxaglate was the most potent inhibitor of thrombin generation in plasma despite having the least effect on fibrin polymerization. Contrast agents inhibited binding of thrombin to fibrin, with ionic agents producing a more potent effect than ioversol (p <0.02). However, contrast agents did not inhibit thrombin-mediated platelet activation, had only a minor effect on inhibition of thrombin by antithrombin III, and did not affect thrombin-hirudin interactions. In summary, these studies identify specific mechanisms by which radiographic contrast agents inhibit thrombin formation and function – i.e. inhibition of tissue factor-dependent factor Xa generation, inhibition of the prothrombinase complex, and inhibition of thrombin binding to fibrin. These findings may help to explain the reduced risk of thrombosis during coronary angioplasty associated with ionic contrast agents.

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