Search results for "contrast agent"
showing 10 items of 36 documents
Silica-coated superparamagnetic nanoparticles as contrast agent for magnetic resonance imaging: Synthesis and physicological charaterizations
2015
Superparamagnetic iron oxide nanoparticles (SPIONs) have received a growing interest for various biomedical applications due to their interesting magnetic properties. Herein, we report a method for facile synthesis of colloidal silica-coated superparamagnetic iron oxide nanoparticles (Si-SPIONs). The polyvinyl alcohol (PVA)-SPIONs were successfully prepared and then coated with silica by the modified Stober method. The obtained Si-SPIONs are highly monodisperse with uniform morphology. Notably, comparing to uncoated SPIONs, silica coated ones show colloidal stability region at physiological pH which is applicable in biomedical applications and synthesis at the scale of grams was easily obta…
Gadolinium-chelating nanogels as MR contrast agents specifically targeting tumor cells
2014
Aims and objectives Methods and materials Results Conclusion Personal information References
The use of theranostic gadolinium-based nanoprobes to improve radiotherapy efficacy
2014
International audience; A new efficient type of gadolinium-based theranostic agent (AGuIX) has recently been developed for magnetic resonance imaging (MRI)-guided radiotherapy. These new particles consist of a polysiloxane network surrounded by a number of gadolinium chelates, usually 10. Due to their small size (<5 nm), AGuIX typically exhibit biodistributions that are almost ideal for diagnostic and therapeutic purposes. For example, while a significant proportion of these particles accumulate in tumours, the remainder is rapidly eliminated by the renal route. In addition, these particles present no evidence of toxicity, in the absence of irradiation with up to 10 times the planned dose f…
MSCT in GIST patients with hepatic metastases treated with new generation tyrosinkinase inhibitors: comparison between density and dimension
2013
Purpose Methods and Materials Results Conclusion References Personal Information
Synthetic strategy for preparation of a folate corrole DOTA heterobimetallic Cu–Gd complex as a potential bimodal contrast agent in medical imaging
2015
Abstract An efficient sequential route to synthesize heterobimetallic complexes is reported herein. A folate, Cu corrole, Gd DOTA complex that addresses the requirements of a potential contrast agent (CA) for bimodal imaging (e.g., MRI/PET) is reported. The over-expression of the folate receptor in a variety of malignant tumors, along with its limited expression in healthy tissues, makes this an attractive tumor-specific molecular target. Synthesis of a bimetallic ligand potentially targeting the folate receptor, was easily achieved in only a few steps. Interestingly, preliminary studies showed that the relaxivity of the folic heterobimetallic derivative was higher in comparison to a clinic…
Qualitative and quantitative evaluation of solitary thyroid nodules with contrast-enhanced ultrasound: initial results
2005
To assess the feasibility of contrast-enhanced ultrasound (CEUS) of the thyroid gland and to evaluate the potential of this method for characterising solitary thyroid nodules.18 patients affected by solitary thyroid nodules (size range: 0.6 to 3.6 cm; mean: 1.8 cm) confirmed by surgery (nine papillary carcinomas, four follicular carcinomas, three hyperplasias, one follicular adenoma and one Plummer’s adenoma) underwent pulse inversion US at low M.I. (0.06 to 0.08) after i.v. injection of a 2.4-mL bolus of SonoVue. Baseline echogenicity and the dynamic enhancement pattern of each nodule, in comparison with adjacent thyroid parenchyma, were assessed. Signal intensity values on grey-scale imag…
Multiproperty complexes of 4d and 4f metal ions based on biomolecules: from fundamental research to potential applications
2023
El trabajo desarrollado en esta Tesis se enmarca en el campo de la Química de Coordinación y el Magnetismo Molecular, vectores base para el desarrollo de múltiples aplicaciones en Nanomedicina y Nanotecnología. El estudio de los compuestos de coordinación tiene una larga historia que se remonta a principios del siglo XIX, con notables contribuciones de químicos como Berzelius y Jørgensen. Esta rama de la química se centra en la comprensión de las propiedades de unión de los ligandos (moléculas o aniones donadores de electrones) a los iones metálicos. Las teorías de Alfred Werner sobre la coordinación de iones metálicos a principios del siglo XX marcaron un hito importante en este campo. El …
Fluorescein- and EGFR-Antibody Conjugated Silica Nanoparticles for Enhancement of Real-time Tumor Border Definition Using Confocal Laser Endomicrosco…
2019
Intraoperative definition of tumor free resection margins in head and neck cancer is challenging. In the current proof-of-principle study we evaluated a novel silica nanoparticle-based agent for its potential use as contrast enhancer. We synthesized silica nanoparticles with an average size of 45 nm and modified these particles with the fluorescence stain fluorescein isocyanate (FITC) for particle detection and with epidermal growth factor receptor (EGFR)-targeting antibodies for enhanced tumor specificity. The nanoparticles exhibited good biocompatibility and could be detected in vitro and in vivo by confocal laser scanning microscopy. Additionally, we show in an ex vivo setting that these…
Focal liver lesions: clinical usefulness of contrast-enhanced ultrasound in the selection of surgical patients
2009
Purpose: to evaluate the role of contrast-enhanced ultrasound (CEUS) in the characterization of focal liver lesions (FLLs) for surgical patients selection. Materials and Methods: 135 consecutive patients (71 women, 64 men) with 165 FLLs (mean size: 3.1 cm) - 89 benign (10 simple cysts, 26 hemangiomas, 29 focal nodular hyperplasia (FNH), 2 hepatocellular adenomas, 11 focal fatty sparing, 3 focal fatty areas, 5 regenerative nodules, 2 hydatid cysts, 1 abscess) and 76 malignant - 47 metastases, 26 hepatocellular carcinomas and 3 peripheral cholangiocarcinomas - underwent CEUS after the administration of SonoVue®. Two readers reviewed in consensus baseline US and CEUS scans obtained 25-30 s (ar…
A Gadolinium(III) Complex Based on the Thymine Nucleobase with Properties Suitable for Magnetic Resonance Imaging
2021
The paramagnetic gadolinium(III) ion is used as contrast agent in magnetic resonance (MR) imaging to improve the lesion detection and characterization. It generates a signal by changing the relaxivity of protons from associated water molecules and creates a clearer physical distinction between the molecule and the surrounding tissues. New gadolinium-based contrast agents displaying larger relaxivity values and specifically targeted might provide higher resolution and better functional images. We have synthesized the gadolinium(III) complex of formula [Gd(thy)2(H2O)6](ClO4)3·2H2O (1) [thy = 5-methyl-1H-pyrimidine-2,4-dione or thymine], which is the first reported compound based on gadolinium…