The internal structure of gadolinium and perfluorocarbon-loaded polymer nanoparticles affects F MRI relaxation times.

F magnetic resonance imaging (F MRI) is an emerging technique for quantitative imaging in novel therapies, such as cellular therapies and theranostic nanocarriers. Nanocarriers loaded with liquid perfluorocarbon (PFC) typically have a (single) core-shell structure with PFC in the core due to the poor miscibility of PFC with organic and inorganic solvents. Paramagnetic relaxation enhancement acts only at a distance of a few angstroms.

In Vitro Studies Regarding the Safety of Chitosan and Hyaluronic Acid-Based Nanohydrogels Containing Contrast Agents for Magnetic Resonance Imaging.

The aim of this study was to investigate the biocompatibility of contrast agents, such as gadolinium 1, 4, 7, 10 tetraazacyclo-dodecane tetraacetic acid (GdDOTA) and gadolinium dioctyl terephthalate (GdDOTP), encapsulated in a polymeric matrix containing chitosan and hyaluronic acid using RAW264.7 murine macrophages and human blood samples. The cell viability and cytotoxicity were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, while cell cycle analysis was determined in RAW264.

Synthesis and Characterization of Conjugated Hyaluronic Acids. Application to Stability Studies of Chitosan-Hyaluronic Acid Nanogels Based on Fluorescence Resonance Energy Transfer.

Hyaluronic acid (HA) was functionalized with a series of amino synthons (octylamine, polyethylene glycol amine, trifluoropropyl amine, rhodamine). Sodium hyaluronate (HAs) was first converted into its protonated form (HAp) and the reaction was conducted in DMSO by varying the initial ratio (-NH (synthon)/COOH (HAp)). HA derivatives were characterized by a combination of techniques (FTIR, H NMR, 1D diffusion-filtered F NMR, DOSY experiments), and degrees of substitution (DS) varying from 0.

Comparison of MRI Properties between Multimeric DOTAGA and DO3A Gadolinium-Dendron Conjugates.

The inherent lack of sensitivity of MRI needs the development of new Gd contrast agents in order to extend the application of this technique to cellular imaging. For this purpose, two multimeric MR contrast agents obtained by peptidic coupling between an amido amine dendron and GdDOTAGA chelates (premetalation strategy, G1-4GdDOTAGA) or DO3A derivatives which then were postmetalated (G1-4GdDO3A) have been prepared. By comparison to the monomers, an increase of longitudinal relaxivity has been observed for both structures.

Impact of gadolinium-based contrast agents on the growth of fish cells lines.

The present study was the first approach conducted under environmental concentrations of Gd-DOTA and Gd-DTPA-BMA to assess cellular impacts of these compounds. Gd-DOTA (Gadoteric acid) is one of the most stable contrast agent, currently used as Dotarem formulation during Magnetic Resonance Imaging exams. The study was mainly performed on a Zebra Fish cell line (ZF4; ATCC CRL-2050).