Recent Efforts to Develop Imaging Methods and β -Cell-Specific Contrast Agents for Non-Invasive in vivo Assessment of β-Cell Mass

2009 ◽  
Vol 3 (3) ◽  
pp. 157-161
Author(s):  
Stephan Schneider ◽  
John Virostko ◽  
Astrid Reimann ◽  
Alvin Powers
Keyword(s):  
Contrast Agents ◽  
Cell Mass ◽  
Imaging Methods ◽  
Non Invasive ◽  
In Vivo Assessment

scholarly journals Acoustoelasticity Analysis of Transient Waves for Non-Invasive In Vivo Assessment of Urinary Bladder

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mahdi Bayat ◽  
Saba Adabi ◽  
Viksit Kumar ◽  
Adriana Gregory ◽  
Jeremy Webb ◽  
...  
Keyword(s):  
Urinary Bladder ◽  
Transient Waves ◽  
Non Invasive ◽  
In Vivo Assessment

Abstract 3366: Imaging of Peroxidase Activity in Injured Myocardium

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Matthias Nahrendorf ◽  
David E Sosnovik ◽  
John Chen ◽  
Jose-Luis Figueiredo ◽  
Peter Panizzi ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Matrix Proteins ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Non Invasive ◽  
Injured Myocardium ◽  
Reactive Chlorinating Species ◽  
Injury Causes ◽  
In Vivo Assessment

Ischemic myocardial injury causes timed recruitment of neutrophils and monocyte/macrophages, which produce significant amounts of myeloperoxidase (MPO). MPO leads to the formation of reactive chlorinating species capable of oxidizing proteins. We developed a small molecule based MPO substrate for MRI, Gd-bis-5-HT-DPTA, which is first radicalized, and then oligomerized and covalently bound to matrix proteins, all leading to enhanced R1-relaxivity and delayed wash out kinetics. Mice were subjected to coronary artery ligation and injected with 0.3mmol/kg Gd-bis-5-HT-DPTA (or Gd-DTPA as control). We performed T1-weighted cardio-respiratory gated MRI 10–120min later, followed by immunoreactive staining for MPO. 3 mice each were studied at day 1, 2, 4, 8, and >1 month after MI. Subsequently, MPO tissue activity was determined with the guaiacol method. MPO activity peaked 2 days after MI (contrast-to-noise-ratio (CNR) day 1, 26+/−4; day 2, 39+/−10; day 4, 29+/−3), and tissue levels of MPO over time correlated well with probe activity in vivo (r2=0.65, p<0.01). CNR following Gd-DTPA peaked ten minutes after injection (10.5+/−0.2), and returned to pre-injection values at 60min. In contradistinction, following injection Gd-bis-5-HT-DPTA, CNR was higher and peaked later (p<0.05 vs. Gd-DTPA, arrows depict MI in figure ). Immunoreactive staining for MPO correlated well with enhancement (r2=0.92, p<0.05). Gd-bis-5-HT-DPTA facilitates in-vivo assessment of MPO activity in injured myocardium. This approach allows non-invasive probing of the inflammatory response to ischemia and has the potential to guide the development and application of novel cardioprotective therapies.

scholarly journals Melanin distribution from the dermal–epidermal junction to the stratum corneum: non-invasive in vivo assessment by fluorescence and Raman microspectroscopy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
B. P. Yakimov ◽  
E. A. Shirshin ◽  
J. Schleusener ◽  
A. S. Allenova ◽  
V. V. Fadeev ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Raman Microspectroscopy ◽  
Non Invasive ◽  
In Vivo Assessment

In Vivo Assessment of the Potential for Renal Bio-Effects from the Vaporization of Perfluorocarbon Phase-Change Contrast Agents

2018 ◽  
Vol 44 (2) ◽  
pp. 368-376 ◽  
Author(s):  
A. Gloria Nyankima ◽  
Juan D. Rojas ◽  
Rachel Cianciolo ◽  
Kennita A. Johnson ◽  
Paul A. Dayton
Keyword(s):  
Phase Change ◽  
Contrast Agents ◽  
In Vivo Assessment

scholarly journals Non-invasive Beta-cell Imaging: Visualization, Quantification, and Beyond

2021 ◽  
Vol 12 ◽  
Author(s):  
Takaaki Murakami ◽  
Hiroyuki Fujimoto ◽  
Nobuya Inagaki
Keyword(s):  
Diabetes Mellitus ◽  
Cell Imaging ◽  
Diabetes Management ◽  
Single Photon ◽  
Cell Mass ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Β Cell ◽  
Non Invasive

Pancreatic beta (β)-cell dysfunction and reduced mass play a central role in the development and progression of diabetes mellitus. Conventional histological β-cell mass (BCM) analysis is invasive and limited to cross-sectional observations in a restricted sampling area. However, the non-invasive evaluation of BCM remains elusive, and practical in vivo and clinical techniques for β-cell-specific imaging are yet to be established. The lack of such techniques hampers a deeper understanding of the pathophysiological role of BCM in diabetes, the implementation of personalized BCM-based diabetes management, and the development of antidiabetic therapies targeting BCM preservation and restoration. Nuclear medical techniques have recently triggered a major leap in this field. In particular, radioisotope-labeled probes using exendin peptides that include glucagon-like peptide-1 receptor (GLP-1R) agonist and antagonist have been employed in positron emission tomography and single-photon emission computed tomography. These probes have demonstrated high specificity to β cells and provide clear images accurately showing uptake in the pancreas and transplanted islets in preclinical in vivo and clinical studies. One of these probes, 111indium-labeled exendin-4 derivative ([Lys12(111In-BnDTPA-Ahx)]exendin-4), has captured the longitudinal changes in BCM during the development and progression of diabetes and under antidiabetic therapies in various mouse models of type 1 and type 2 diabetes mellitus. GLP-1R-targeted imaging is therefore a promising tool for non-invasive BCM evaluation. This review focuses on recent advances in non-invasive in vivo β-cell imaging for BCM evaluation in the field of diabetes; in particular, the exendin-based GLP-1R-targeted nuclear medicine techniques.

Abstract MP207: A Precision Medicine Approach For Non-invasive, Longitudinal, And Quantitative Monitoring Of Cardiac Tissue-engineered Scaffolds

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Carmen Gil ◽  
Connor Evans ◽  
Lan Li ◽  
Merlyn Vargas ◽  
Gabriella Kabboul ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Precision Medicine ◽  
Cardiac Tissue ◽  
Ct Imaging ◽  
3D Bioprinting ◽  
Au Nps ◽  
Non Invasive ◽  
Functional Features

3D bioprinting has revolutionized personalized and precision medicine by enabling the manufacturing of tissue constructs that precisely recapitulate the cellular and functional features of native tissues. In cardiac regenerative medicine, printed scaffolds have shown tremendous potential in repairing damaged heart, however, their clinical applications have been limited by the lack of precise noninvasive tools to monitor the patch function following implantation. By integrating state-of-the-art 3D bioprinting and photon-counting computed tomography (PCCT), this study introduces a new approach for bioengineering defect-specific scaffolds and monitoring their function. We prepared distinct CT-visible bioinks containing a variety of molecular or nanoparticle (NP) contrast agents, including iodine and gadolinium molecules, Au NPs, Gd 2 O 3 NPs, and iodine-loaded liposomes ( Fig 1A-B ). In vitro release experiments showed relatively rapid diffusion-controlled depletion of molecular contrast agents from scaffolds. In contrast, NP agents showed more stable encapsulation and only a partial, degradation-mediated release for up to 3 weeks of incubation ( Fig 1C-D ). Next, PCCT imaging was performed on various scaffold geometries printed using bioinks laden with Gd 2 O 3 or Au NPs. Results demonstrated CT visibility with differential contrast between different patch regions that corresponded to the designed geometries ( Fig 1E ). Finally, we evaluated the in vivo CT imaging of bioprinted patches after their subcutaneous implantation in a mouse model. CT images demonstrated adequate signal from implanted grafts ( Fig 1F ). Together, these results establish a novel precision medicine platform for non-invasive monitoring of medical devices which can open new prospects for a broad range of tissue engineering applications. Figure 1. 3D Bioprinting of CT-visible cardiac patches. A-B: Design of bioinks functionalized with molecular (left) and nanoparticle (right) CT contrast agents ( A ) and their bioprinting ( B ). C-D: In vitro release of contrast agents from printed patches. E: CAD design (left), CT image (middle), and PCCT material decomposition (right) for multi-contrast bioprinted scaffolds. F: In vivo CT imaging of printed patch, laden with Au NPs, implanted subcutaneously into a mouse torso.

scholarly journals Sensitive detection of extremely small iron oxide nanoparticles in living mice using MP2RAGE with advanced image co-registration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joong H. Kim ◽  
Stephen Dodd ◽  
Frank Q. Ye ◽  
Andrew K. Knutsen ◽  
Duong Nguyen ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Contrast Agents ◽  
Iron Oxide Nanoparticles ◽  
Mouse Brain ◽  
Oxide Nanoparticles ◽  
Non Invasive ◽  
T1 Map ◽  
Magnetic Resonance Imaging Mri ◽  
Molecular Contrast

AbstractMagnetic resonance imaging (MRI) is a widely used non-invasive methodology for both preclinical and clinical studies. However, MRI lacks molecular specificity. Molecular contrast agents for MRI would be highly beneficial for detecting specific pathological lesions and quantitatively evaluating therapeutic efficacy in vivo. In this study, an optimized Magnetization Prepared—RApid Gradient Echo (MP-RAGE) with 2 inversion times called MP2RAGE combined with advanced image co-registration is presented as an effective non-invasive methodology to quantitatively detect T1 MR contrast agents. The optimized MP2RAGE produced high quality in vivo mouse brain T1 (or R1 = 1/T1) map with high spatial resolution, 160 × 160 × 160 µm3 voxel at 9.4 T. Test–retest signal to noise was > 20 for most voxels. Extremely small iron oxide nanoparticles (ESIONPs) having 3 nm core size and 11 nm hydrodynamic radius after polyethylene glycol (PEG) coating were intracranially injected into mouse brain and detected as a proof-of-concept. Two independent MP2RAGE MR scans were performed pre- and post-injection of ESIONPs followed by advanced image co-registration. The comparison of two T1 (or R1) maps after image co-registration provided precise and quantitative assessment of the effects of the injected ESIONPs at each voxel. The proposed MR protocol has potential for future use in the detection of T1 molecular contrast agents.

scholarly journals Non-invasive and in vivo assessment of osteoarthritic articular cartilage: a review on MRI investigations

2014 ◽  
Vol 35 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Ahmad Fadzil Mohd Hani ◽  
Dileep Kumar ◽  
Aamir Saeed Malik ◽  
Raja Mohd Kamil Raja Ahmad ◽  
Ruslan Razak ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Non Invasive ◽  
In Vivo Assessment
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