scholarly journals Predicting in vivo fluorescence lifetime behavior of near-infrared fluorescent contrast agents using in vitro measurements

2008 ◽  
Vol 13 (5) ◽  
pp. 054042 ◽  
Author(s):  
Walter J. Akers ◽  
Mikhail Y. Berezin ◽  
Hyeran Lee ◽  
Samuel Achilefu
Keyword(s):  
Contrast Agents ◽  
Fluorescence Lifetime ◽  
Near Infrared ◽  
In Vivo Fluorescence ◽  
In Vitro Measurements

A novel near-infrared fluorescent probe with a large Stokes shift for biothiol detection and application in in vitro and in vivo fluorescence imaging

2017 ◽  
Vol 5 (21) ◽  
pp. 3836-3841 ◽  
Author(s):  
Keyin Liu ◽  
Huiming Shang ◽  
Xiuqi Kong ◽  
Weiying Lin
Keyword(s):  
Fluorescent Probe ◽  
Fluorescence Imaging ◽  
Near Infrared ◽  
Stokes Shift ◽  
Large Stokes Shift ◽  
In Vivo Fluorescence ◽  
In Vivo Fluorescence Imaging

A novel near-infrared fluorescent probe with a large Stokes shift was developed for biothiol detection and application in in vitro and in vivo fluorescence imaging.

Push–pull type meso-ester substituted BODIPY near-infrared dyes as contrast agents for photoacoustic imaging

2017 ◽  
Vol 15 (21) ◽  
pp. 4531-4535 ◽  
Author(s):  
Yong Ni ◽  
Ravi Kumar Kannadorai ◽  
Sidney W.-K. Yu ◽  
Young-Tae Chang ◽  
Jishan Wu
Keyword(s):  
Contrast Agents ◽  
Near Infrared ◽  
Photoacoustic Imaging ◽  
Nir Absorption ◽  
Photo Stability

Push–pull meso-ester BODIPYs with intense NIR absorption and good photo-stability were used for in vitro and in vivo photoacoustic imaging.

scholarly journals Comparison of Folate Receptor Targeted Optical Contrast Agents for Intraoperative Molecular Imaging

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Elizabeth De Jesus ◽  
Jane J. Keating ◽  
Sumith A. Kularatne ◽  
Jack Jiang ◽  
Ryan Judy ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Animal Studies ◽  
Near Infrared ◽  
Fluorescent Dyes ◽  
Folate Receptor ◽  
Intraoperative Imaging ◽  
Nir Dyes ◽  
Optical Contrast Agents

Background. Intraoperative imaging can identify cancer cells in order to improve resection; thus fluorescent contrast agents have emerged. Our objective was to do a preclinical comparison of two fluorescent dyes, EC17 and OTL38, which both target folate receptor but have different fluorochromes. Materials. HeLa and KB cells lines were used for in vitro and in vivo comparisons of EC17 and OTL38 brightness, sensitivity, pharmacokinetics, and biodistribution. In vivo experiments were then performed in mice. Results. The peak excitation and emission wavelengths of EC17 and OTL38 were 470/520 nm and 774/794 nm, respectively. In vitro, OTL38 required increased incubation time compared to EC17 for maximum fluorescence; however, peak signal-to-background ratio (SBR) was 1.4-fold higher compared to EC17 within 60 minutes (p<0.001). Additionally, the SBR for detecting smaller quantity of cells was improved with OTL38. In vivo, the mean improvement in SBR of tumors visualized using OTL38 compared to EC17 was 3.3 fold (range 1.48–5.43). Neither dye caused noticeable toxicity in animal studies. Conclusions. In preclinical testing, OTL38 appears to have superior sensitivity and brightness compared to EC17. This coincides with the accepted belief that near infrared (NIR) dyes tend to have less autofluorescence and scattering issues than visible wavelength fluorochromes.

scholarly journals In vitro and in vivo NIR Fluorescence Lifetime Imaging with a time-gated SPAD camera

2021 ◽  
Author(s):  
Jason T. Smith ◽  
Alena Rudkouskaya ◽  
Shan Gao ◽  
Juhi M. Gupta ◽  
Arin Ulku ◽  
...  
Keyword(s):  
Fluorescence Lifetime ◽  
Near Infrared ◽  
Single Photon ◽  
In Vivo Studies ◽  
Fluorescence Lifetime Imaging ◽  
Iccd Camera ◽  
Lifetime Imaging ◽  
Nir Fluorescence

Near-infrared (NIR) fluorescence lifetime imaging (FLI) provides a unique contrast mechanism to monitor biological parameters and molecular events in vivo. Single-photon avalanche photodiode (SPAD) cameras have been recently demonstrated in FLI microscopy (FLIM) applications, but their suitability for in vivo macroscopic FLI (MFLI) in deep tissues remains to be demonstrated. Herein, we report in vivo NIR MFLI measurement with SwissSPAD2, a large time-gated SPAD camera. We first benchmark its performance in well-controlled in vitro experiments, ranging from monitoring environmental effects on fluorescence lifetime, to quantifying Förster Resonant Energy Transfer (FRET) between dyes. Next, we use it for in vivo studies of target-drug engagement in live and intact tumor xenografts using FRET. Information obtained with SwissSPAD2 was successfully compared to that obtained with a gated-ICCD camera, using two different approaches. Our results demonstrate that SPAD cameras offer a powerful technology for in vivo preclinical applications in the NIR window.

Tantalum Oxide Nanoparticles as Versatile Contrast Agents for X-ray Computed Tomography

2020 ◽  
Author(s):  
Shatadru Chakravarty ◽  
Jeremy Hix ◽  
Kaitlyn Wieweora ◽  
Maximilian Volk ◽  
Elizabeth Kenyon ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Tantalum Oxide ◽  
High Signal ◽  
Drug Delivery Vehicles ◽  
X Ray Computed

Here we describe the synthesis, characterization and in vitro and in vivo performance of a series of tantalum oxide (TaOx) based nanoparticles (NPs) for computed tomography (CT). Five distinct versions of 9-12 nm diameter silane coated TaOx nanocrystals (NCs) were fabricated by a sol-gel method with varying degrees of hydrophilicity and with or without fluorescence, with the highest reported Ta content to date (78%). Highly hydrophilic NCs were left bare and were evaluated in vivo in mice for micro-CT of full body vasculature, where following intravenous injection, TaOx NCs demonstrate high CT contrast, circulation in blood for ~ 3 h, and eventual accumulation in RES organs; and following injection locally in the mammary gland, where the full ductal tree structure can be clearly delineated. Partially hydrophilic NCs were encapsulated within mesoporous silica nanoparticles (MSNPs; TaOx@MSNPs) and hydrophobic NCs were encapsulated within poly(lactic-co-glycolic acid) (PLGA; TaOx@PLGA) NPs, serving as potential CT-imagable drug delivery vehicles. Bolus intramuscular injections of TaOx@PLGA NPs and TaOx@MSNPs to mimic the accumulation of NPs at a tumor site produce high signal enhancement in mice. In vitro studies on bare NCs and formuated NPs demonstrate high cytocompatibility and low dissolution of TaOx. This work solidifies that TaOx-based NPs are versatile contrast agents for CT.

scholarly journals Study on Establishing Reference Safe Concentrations of MRI Contrast Agents for Optimized Images: Paramagnetic Gd-DTPA-BMEA and Superparamagnetic Ferucarbotran

2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
In Vitro Experiments ◽  
Mri Contrast ◽  
In Vivo Experiments ◽  
Contrast Agent Injection

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.

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