177 research outputs found
MRI Tracking of Macrophages Labeled with Glucan Particles Entrapping a Water Insoluble Paramagnetic Gd-Based Agent.
PURPOSE: This study is aimed at demonstrating the in vivo potential of Gd(III)-loaded glucan particles (Gd-GPs) as magnetic resonance imaging (MRI)-positive agents for labeling and tracking phagocytic cells.
PROCEDURE: GPs were obtained from Saccharomyces cerevisae and loaded with the water-insoluble complex Gd-DOTAMA(C18)2. The uptake kinetics of Gd-GPs by murine macrophages was studied in vitro and the internalization mechanism was assessed by competition assays. The in vivo performance of Gd-GPs was tested at 7.05 T on a mouse model of acute liver inflammation.
RESULTS: The minimum number of Gd-GPs-labeled J774.A1 macrophages detected in vitro by MRI was ca. 300 cells/μl of agar, which is the lowest number ever reported for cells labeled with a positive T1 agent. Intravenous injection of macrophages labeled with Gd-GPs in a mouse model of liver inflammation enabled the MRI visualization of the cellular infiltration in the diseased area.
CONCLUSIONS: Gd-GPs represent a promising platform for tracking macrophages by MRI as a T1 alternative to the golden standard T2-based iron oxide particles
First in vivo MRI study on theranostic dendrimersomes
Amphiphilic Janus-dendrimers are able to self-assemble into nanosized vesicles named dendrimersomes.We recently
synthesized the 3,5-C12-EG-(OH)4 dendrimer that generates dendrimersomes with very promising safety
and stability profiles, that can be loaded with different contrast agents for in vivo imaging. In this contribution,
nanovesicles were loaded with both the Magnetic Resonance Imaging (MRI) reporter GdDOTAGA(C18)2 and
the glucocorticoid drug Prednisolone Phosphate (PLP), in order to test their effective potential as theranostic
nanocarriers on murine melanoma tumour models. The incorporation of GdDOTAGA(C18)2 into the membrane
resulted in dendrimersomes with a high longitudinal relaxivity (r1 = 39.1 mM−1 s−1, at 310 K and 40 MHz)
so that, after intravenous administration, T1-weighted MRI showed a consistent contrast enhancement in the tumour
area. Furthermore, the nanovesicles encapsulated PLP with good efficiency and displayed anti-tumour activity
both in vitro and in vivo, thus enabling their practical use for biomedical theranostic applications
Successful in vivo MRI tracking of MSCs labelled with Gadoteridol in a Spinal Cord Injury experimental model
In this study, murine Mesenchymal Stem Cells (MSCs) labeled with the clinically approved MRI agent Gadoteridol through a procedure based on the hypo-osmotic shock were successfully tracked in vivo in a murine model of Spinal Cord Injury (SCI). With respect to iso-osmotic incubations, the hypo-osmotic labeling significantly increased the Gd(3+) cellular uptake, and enhanced both the longitudinal relaxivity (r1) of the intracellular Gadoteridol and the Signal to Noise Ratio (SNR) measured on cell pellets, without altering the biological and functional profile of cells. A substantial T1 Contrast Enhancement after local transplantation of 3.0×10(5) labeled cells in SCI mice enabled to follow their migratory dynamics in vivo for about 10days, and treated animals recovered from the motor impairment caused by the injury, indicating unaltered therapeutic efficacy. Finally, analytical and histological data corroborated the imaging results, highlighting the opportunity to perform a precise and reliable monitoring of the cell-based therapy
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