Is There Preclinical and Clinical Value for F MRI in Stem Cell Cardiac Regeneration?

Cardiovascular regeneration aims to renew damaged or necrotic tissue and to enhance cardiac functional performance. Despite the hope arisen from the introduction and use of stem cells (SCs) as a novel cardiac regenerative approach, to-this-date, clinical trial findings are still ambivalent despite preclinical successes. Concurrently, noninvasive magnetic resonance imaging (MRI) advances have been based on nanotechnological breakthroughs that have (a) allowed fluorinated nanoparticles and ultrasmall iron oxide single-cell labeling, (b) explored imaging detection sensitivity limits (for preclinical/low-field clinical settings), and (c) accomplished cellular tracking .

Correction: Fast, quantitative, murine cardiac 19F MRI/MRS of PFCE-labeled progenitor stem cells and macrophages at 9.4T.

[This corrects the article DOI: 10.1371/journal.pone.

Improved cellular uptake of perfluorocarbon nanoparticles for in vivo murine cardiac F MRS/MRI and temporal tracking of progenitor cells.

Herein, we maximize the labeling efficiency of cardiac progenitor cells (CPCs) using perfluorocarbon nanoparticles (PFCE-NP) and F MRI detectability, determine the temporal dynamics of single-cell label uptake, quantify the temporal viability/fluorescence persistence of labeled CPCs in vitro, and implement in vivo, murine cardiac CPC MRI/tracking that could be translatable to humans. FuGENE-mediated CPC PFCE-NP uptake is confirmed with flow cytometry/confocal microscopy. Epifluorescence imaging assessed temporal viability/fluorescence (up to 7 days [D]).

In Vivo Tracking and H/F Magnetic Resonance Imaging of Biodegradable Polyhydroxyalkanoate/Polycaprolactone Blend Scaffolds Seeded with Labeled Cardiac Stem Cells.

Medium-chain length polyhydroxyalkanoates (MCL-PHAs) have demonstrated exceptional properties for cardiac tissue engineering (CTE) applications. Despite prior work on MCL-PHA/polycaprolactone (PCL) blends, optimal scaffold production and use as an alternative delivery route for controlled release of seeded cardiac progenitor cells (CPCs) in CTE applications in vivo has been lacking. We present herein applicability of MCL-PHA/PCL (95/5 wt %) blends fabricated as thin films with an improved performance compared to the neat MCL-PHA.

Fast, quantitative, murine cardiac 19F MRI/MRS of PFCE-labeled progenitor stem cells and macrophages at 9.4T.

Purpose: To a) achieve cardiac 19F-Magnetic Resonance Imaging (MRI) of perfluoro-crown-ether (PFCE) labeled cardiac progenitor stem cells (CPCs) and bone-derived bone marrow macrophages, b) determine label concentration and cellular load limits, and c) achieve spectroscopic and image-based quantification.

Methods: Theoretical simulations and experimental comparisons of spoiled-gradient echo (SPGR), rapid acquisition with relaxation enhancement (RARE), and steady state at free precession (SSFP) pulse sequences, and phantom validations, were conducted using 19F MRI/Magnetic Resonance Spectroscopy (MRS) at 9.4 T.

Performance evaluation of GPU parallelization, space-time adaptive algorithms, and their combination for simulating cardiac electrophysiology.

The use of computer models as a tool for the study and understanding of the complex phenomena of cardiac electrophysiology has attained increased importance nowadays. At the same time, the increased complexity of the biophysical processes translates into complex computational and mathematical models. To speed up cardiac simulations and to allow more precise and realistic uses, 2 different techniques have been traditionally exploited: parallel computing and sophisticated numerical methods.

Temporal accumulation and localization of isoflurane in the C57BL/6 mouse and assessment of its potential contamination in F MRI with perfluoro-crown-ether-labeled cardiac progenitor cells at 9.4 Tesla.

Purpose: To assess the uptake, accumulation, temporal stability, and spatial localization of isoflurane (ISO) in the C57BL/6 mouse, and to identify its potential interference with the detection of labeled cardiac progenitor cells using F MRI/MR spectroscopy (MRS).

Materials And Methods: Objectives are demonstrated using (a) in vitro ISO tests, (b) in vivo temporal accumulation/spatial localization C57BL/6 studies (n = 3), and (c) through injections of perfluoro-crown-ether (PFCE) labeled cardiac progenitor cells into femoral muscle areas of the murine hindlimb post-mortem (n = 1) using H/ F MRI/MRS at 9.4 Tesla.

Molecular and Integrative Physiological Effects of Isoflurane Anesthesia: The Paradigm of Cardiovascular Studies in Rodents using Magnetic Resonance Imaging.

To-this-date, the exact molecular, cellular, and integrative physiological mechanisms of anesthesia remain largely unknown. Published evidence indicates that anesthetic effects are multifocal and occur in a time-dependent and coordinated manner, mediated via central, local, and peripheral pathways. Their effects can be modulated by a range of variables, and their elicited end-effect on the integrative physiological response is highly variable.

A high-resolution cardiovascular magnetic resonance diffusion tensor map from ex-vivo C57BL/6 murine hearts.

Background: The complex cardiac fiber structural organization and spatial arrangement of cardiomyocytes in laminar sheetlets contributes greatly to cardiac functional and contractile ejection patterns. This study presents the first comprehensive, ultra-high resolution, fully quantitative statistical tensor map of the fixed murine heart at isotropic resolution of 43 μm using diffusion tensor (DT) cardiovascular magnetic resonance (CMR).

Methods: Imaging was completed in approximately 12 hours using a six-directional encoding scheme, in five ex vivo healthy C57BL/6 mouse hearts.

Elimination of mutual inductance in NMR phased arrays: the paddle design revisited.

This study proposes a method to empirically minimize mutual inductance, using passive end-ring circular paddles, with neighboring coil loops placed in a non-overlapped configuration. The proposed concepts are validated through B(1)-field simulations for resonant coils at f(o)=300.5 MHz, having various sizes (3-10 cm), and for paddles with sizes ranging from 16 to 30 mm, and bench tests on constructed 4×4cm(2) two- (1×2) and four-coil loop (2×2) planar arrays.

Murine cardiac catheterizations and hemodynamics: on the issue of parallel conductance.

Catheter-based measurements are extensively used nowadays in animal models to quantify global left ventricular (LV) cardiac function and hemodynamics. Conductance catheter measurements yield estimates of LV volumes. Such estimates, however, are confounded by the catheter's nonhomogeneous emission field and the contribution to the total conductance of surrounding tissue or blood conductance values (other than LV blood), a term often known as parallel conductance.

INTERCOMPARISON OF PERFORMANCE OF RF COIL GEOMETRIES FOR HIGH FIELD MOUSE CARDIAC MRI.

Multi-turn spiral surface coils are constructed in flat and cylindrical arrangements and used for high field (7.1 T) mouse cardiac MRI. Their electrical and imaging performances, based on experimental measurements, simulations, and MRI experiments in free space, and under phantom, and animal loading conditions, are compared with a commercially available birdcage coil.

Morphological studies of the murine heart based on probabilistic and statistical atlases.

This study directly compares morphological features of the mouse heart in its end-relaxed state based on constructed morphometric maps and atlases using principal component analysis in C57BL/6J (n=8) and DBA (n=5) mice. In probabilistic atlases, a gradient probability exists for both strains in longitudinal locations from base to apex. Based on the statistical atlases, differences in size (49.

Effects of isoflurane anesthesia on the cardiovascular function of the C57BL/6 mouse.

Isoflurane (ISO) is the most commonly used inhalational anesthetic for experimental interventions in mice and is preferred for imaging technologies that require the mouse to remain anesthetized for relatively long time periods. This study compares the stability of mean arterial pressure (MAP), heart rate (HR), and body temperature under ISO concentrations of 1%, 1.5%, and 2% (volume-to-volume, v/v) for up to 90 minutes postinduction.