WFUMB safety symposium on echo-contrast agents: In vitro bioeffects

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.

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

Applied Sciences ◽

10.3390/app11031165 ◽

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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Water-soluble magnetic CoO nanocrystals functionalized with surfactants as T2-weighed MRI contrast agents in vitro

Dalton Transactions ◽

10.1039/c1dt10107b ◽

2011 ◽

Vol 40 (14) ◽

pp. 3616 ◽

Cited By ~ 14

Author(s):

Hong Yang ◽

Hong Zhou ◽

Cuixia Zhang ◽

Xuejian Li ◽

He Hu ◽

...

Keyword(s):

Contrast Agents ◽

Mri Contrast Agents ◽

Water Soluble ◽

Mri Contrast

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Enhancement of ultrasound-accelerated thrombolysis by echo contrast agents: dependence on microbubble structure

Ultrasound in Medicine & Biology ◽

10.1016/s0301-5629(99)00095-2 ◽

1999 ◽

Vol 25 (9) ◽

pp. 1431-1437 ◽

Cited By ~ 67

Author(s):

Katsufumi Mizushige ◽

Isao Kondo ◽

Koji Ohmori ◽

Kenichi Hirao ◽

Hirohide Matsuo

Keyword(s):

Contrast Agents ◽

Echo Contrast Agents

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Polymeric/Inorganic Multifunctional Nanoparticles for Simultaneous Drug Delivery and Visualization

MRS Proceedings ◽

10.1557/proc-1257-o04-03 ◽

2010 ◽

Vol 1257 ◽

Cited By ~ 2

Author(s):

Andrea Fornara ◽

Alberto Recalenda ◽

Jian Qin ◽

Abhilash Sugunan ◽

Fei Ye ◽

...

Keyword(s):

Drug Delivery ◽

Fluorescence Microscopy ◽

Contrast Agents ◽

Gold Nanorods ◽

In Vitro Cytotoxicity ◽

In Vivo Studies ◽

Multifunctional Nanoparticles ◽

Cytotoxicity Studies

AbstractNanoparticles consisting of different biocompatible materials are attracting a lot of interest in the biomedical area as useful tools for drug delivery, photo-therapy and contrast enhancement agents in MRI, fluorescence and confocal microscopy. This work mainly focuses on the synthesis of polymeric/inorganic multifunctional nanoparticles (PIMN) based on biocompatible di-block copolymer poly(L,L-lactide-co-ethylene glycol) (PLLA-PEG) via an emulsion-evaporation method. Besides containing a hydrophobic drug (Indomethacin), these polymeric nanoparticles incorporate different visualization agents such as superparamagnetic iron oxide nanoparticles (SPION) and fluorescent Quantum Dots (QDs) that are used as contrast agents for Magnetic Resonance Imaging (MRI) and fluorescence microscopy together. Gold Nanorods are also incorporated in such nanostructures to allow simultaneous visualization and photodynamic therapy. MRI studies are performed with different loading of SPION into PIMN, showing an enhancement in T2 contrast superior to commercial contrast agents. Core-shell QDs absorption and emission spectra are recorded before and after their loading into PIMN. With these polymeric/inorganic multifunctional nanoparticles, both MRI visualization and confocal fluorescence microscopy studies can be performed. Gold nanorods are also synthesized and incorporated into PIMN without changing their longitudinal absorption peak usable for lased excitation and phototherapy. In-vitro cytotoxicity studies have also been performed to confirm the low cytotoxicity of PIMN for further in-vivo studies.

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