Fluorescent oligo(p-phenyleneethynylene) contained amphiphiles-encapsulated magnetic nanoparticles for targeted magnetic resonance and two-photon optical imaging in vitro and in vivo

Nanoscale ◽  
2015 ◽  
Vol 7 (19) ◽  
pp. 8907-8919 ◽  
Author(s):  
Chao Yin ◽  
Binbin Hong ◽  
Zhaocui Gong ◽  
Hui Zhao ◽  
Wenbo Hu ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Resonance ◽  
Optical Imaging ◽  
Two Photon

scholarly journals Fluorinated PLGA-PEG-Mannose Nanoparticles for Tumor-Associated Macrophage Detection by Optical Imaging and MRI

2021 ◽  
Vol 8 ◽  
Author(s):  
Giorgia Zambito ◽  
Siyuan Deng ◽  
Joost Haeck ◽  
Natasa Gaspar ◽  
Uwe Himmelreich ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Optical Imaging ◽  
Tumor Development ◽  
Mannose Receptor ◽  
The Body ◽  
Mri Contrast Agent ◽  
Therapeutic Interventions ◽  
Magnetic Resonance Imaging Mri

Tumor-associated macrophages (TAMs) promote cancer growth and metastasis, but their role in tumor development needs to be fully understood due to the dynamic changes of tumor microenvironment (TME). Here, we report an approach to visualize TAMs by optical imaging and by Fluorine-19 (19F) magnetic resonance imaging (MRI) that is largely applied to track immune cells in vivo. TAMs are targeted with PLGA-PEG-mannose nanoparticles (NPs) encapsulating perfluoro-15-crown-5-ether (PFCE) as MRI contrast agent. These particles are preferentially recognized and phagocytized by TAMs that overexpress the mannose receptor (MRC1/CD206). The PLGA-PEG-mannose NPs are not toxic and they were up-taken by macrophages as confirmed by in vitro confocal microscopy. At 48 h after intravenous injection of PLGA-PEG-mannose NPs, 4T1 xenograft mice were imaged and fluorine-19 nuclear magnetic resonance confirmed nanoparticle retention at the tumor site. Because of the lack of 19F background in the body, observed 19F signals are robust and exhibit an excellent degree of specificity. In vivo imaging of TAMs in the TME by 19F MRI opens the possibility for detection of cancer at earlier stage and for prompt therapeutic interventions in solid tumors.

scholarly journals Cellular correlates of gray matter volume changes in magnetic resonance morphometry identified by two-photon microscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Livia Asan ◽  
Claudia Falfán-Melgoza ◽  
Carlo A. Beretta ◽  
Markus Sack ◽  
Lei Zheng ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Cell Density ◽  
Gray Matter ◽  
Gray Matter Volume ◽  
Cell Nuclei ◽  
Cellular Mechanisms ◽  
Tissue Volume ◽  
Two Photon ◽  
Matter Volume

AbstractMagnetic resonance imaging (MRI) of the brain combined with voxel-based morphometry (VBM) revealed changes in gray matter volume (GMV) in various disorders. However, the cellular basis of GMV changes has remained largely unclear. We correlated changes in GMV with cellular metrics by imaging mice with MRI and two-photon in vivo microscopy at three time points within 12 weeks, taking advantage of age-dependent changes in brain structure. Imaging fluorescent cell nuclei allowed inferences on (i) physical tissue volume as determined from reference spaces outlined by nuclei, (ii) cell density, (iii) the extent of cell clustering, and (iv) the volume of cell nuclei. Our data indicate that physical tissue volume alterations only account for 13.0% of the variance in GMV change. However, when including comprehensive measurements of nucleus volume and cell density, 35.6% of the GMV variance could be explained, highlighting the influence of distinct cellular mechanisms on VBM results.

Magnetic resonance artifact induced by the electrode Activa 3389: an in vitro and in vivo study

2004 ◽  
Vol 146 (2) ◽  
pp. 161-164 ◽  
Author(s):  
C. Pollo ◽  
J.-G. Villemure ◽  
F. Vingerhoets ◽  
J. Ghika ◽  
P. Maeder ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
In Vivo Study

scholarly journals Imaging the transmembrane and transendothelial sodium gradients in gliomas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad H. Khan ◽  
John J. Walsh ◽  
Jelena M. Mihailović ◽  
Sandeep K. Mishra ◽  
Daniel Coman ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Magnetic Resonance ◽  
Cell Membrane ◽  
Normal Tissue ◽  
Magnetic Resonance Spectroscopic Imaging ◽  
Biological Factors ◽  
High Sodium ◽  
Intracellular Milieu

AbstractUnder normal conditions, high sodium (Na+) in extracellular (Na+e) and blood (Na+b) compartments and low Na+ in intracellular milieu (Na+i) produce strong transmembrane (ΔNa+mem) and weak transendothelial (ΔNa+end) gradients respectively, and these manifest the cell membrane potential (Vm) as well as blood–brain barrier (BBB) integrity. We developed a sodium (23Na) magnetic resonance spectroscopic imaging (MRSI) method using an intravenously-administered paramagnetic polyanionic agent to measure ΔNa+mem and ΔNa+end. In vitro 23Na-MRSI established that the 23Na signal is intensely shifted by the agent compared to other biological factors (e.g., pH and temperature). In vivo 23Na-MRSI showed Na+i remained unshifted and Na+b was more shifted than Na+e, and these together revealed weakened ΔNa+mem and enhanced ΔNa+end in rat gliomas (vs. normal tissue). Compared to normal tissue, RG2 and U87 tumors maintained weakened ΔNa+mem (i.e., depolarized Vm) implying an aggressive state for proliferation, whereas RG2 tumors displayed elevated ∆Na+end suggesting altered BBB integrity. We anticipate that 23Na-MRSI will allow biomedical explorations of perturbed Na+ homeostasis in vivo.

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