In vitro studies on ultrasmall superparamagnetic iron oxide nanoparticles coated with gummic acid for T2 MRI contrast agent

Abstract

Ultrasmall superparamagnetic iron oxide nanoparticles coated with gummic acid have been investigated as possible constituents of aqueous ferrofluids for biomedical applications and especially for MRI contrast agent. The structural characteristics and the size of the nanoparticles have been analyzed as well as the magnetic properties. In order to evaluate any possible capabilities as a contrast agent, the relaxation time, T2, of hydrogen protons in the colloidal solutions of nanoparticles have been measured in order to gain information on the relaxation behavior compared to other MRI contrast agents. The in vitro cytotoxicity of the obtained magnetic nanoparticles of iron oxide coated with gummic acid was investigated by two separate methods ͑MTT and FACS analysis͒ and by using three different normal and transformed cell lines. Our results showed that the synthesized nanoparticles had no toxic effect on any of the cell lines used.

Impact of vaginal microbiome communities on HIV antiretroviral-based pre-exposure prophylaxis (PrEP) drug metabolism

“…However, in samples <5uM, the number of fluorescent cells increased with time for up to 48 hours, indicating viral escape and infection of new target cells. These data match IC50 values for TFV [27]. Of note, at high MOIs (>0.1), a decrease in fluorescence was observed at later time points (post 72 hours), because infected CEM-GFP cells are killed by virus-induced apoptosis [28].…”

Characterization of magnetic nanoparticles as contrast agents in magnetic resonance imaging using high-Tcsuperconducting quantum interference devices in microtesla magnetic fields

“…where MF is the relaxation rate due to the magnetic susceptibility χ caused by the magnetic fluid. Equation (2) represents the effects of the inhomogeneity of the magnetic field on the relaxation time T 2 . In addition to the effect of the field homogeneity, equation 3shows that the magnetic susceptibility will introduce additional effects to the relaxation time T 2 .…”

“…Magnetic nanoparticles are of great interest to those developing new techniques for nuclear magnetic resonance (NMR) [1], magnetic resonance imaging (MRI) [2], magnetically labeled immunoassays [3], magnetic hyperthermia treatments of cancer, cancer diagnostic, therapeutic purposes [4,5], etc. In these technologies, magnetic nanoparticles are introduced to a specific anatomical or functional region being imaged.…”

Magnetic Nanomaterials asMRIContrast Agents

“…Other polymers and copolymers, which have been used to coat magnetic nanoparticles, include PVP) [111 -113] , polyethylenimine ( PEI ) [114] , polyvinyl alcohol ( PVA ) [115 -117] , polysodium -4 -styrene sulfonate [118] , poly(trimethylammonium ethylacrylate methyl sulfate) -poly -(acrylamide) [119] , polyvinylbenzyl -O -beta -D -galactopyranosyl -D -gluconamide (PVLA) [120] , polycaprolactone [121] , and gummic acid [122] . In addition, several stable and biocompatible magnetic fl uids have been prepared by coating magnetic nanoparticles with proteins, such as human serum albumin ( HSA ) [123] , avidin [124] , and Annexin A5 (anxA5) -VSOP [125] .…”