Cancer nanotherapeutics are rapidly progressing and are being implemented to solve several limitations of conventional drug delivery systems such as nonspecific biodistribution and targeting, lack of water solubility, poor oral bioavailability, and low therapeutic indices. To improve the biodistribution of cancer drugs, nanoparticles have been designed for optimal size and surface characteristics to increase their circulation time in the bloodstream. They are also able to carry their loaded active drugs to cancer cells by selectively using the unique pathophysiology of tumors, such as their enhanced permeability and retention effect and the tumor microenvironment. In addition to this passive targeting mechanism, active targeting strategies using ligands or antibodies directed against selected tumor targets amplify the specificity of these therapeutic nanoparticles. Drug resistance, another obstacle that impedes the efficacy of both molecularly targeted and conventional chemotherapeutic agents, might also be overcome, or at least reduced, using nanoparticles. Nanoparticles have the ability to accumulate in cells without being recognized by P-glycoprotein, one of the main mediators of multidrug resistance, resulting in the increased intracellular concentration of drugs. Multifunctional and multiplex nanoparticles are now being actively investigated and are on the horizon as the next generation of nanoparticles, facilitating personalized and tailored cancer treatment.

https://clincancerres.aacrjournals.org/content/clincanres/14/5/1310.full.pdf

Therapeutic Nanoparticles for Drug Delivery in Cancer

Magnetic Nanoparticles in MR Imaging and Drug Delivery

This article reviews the requirements for successful compressed sensing (CS), describes their natural fit to MRI, and gives examples of four interesting applications of CS in MRI. The authors emphasize on an intuitive understanding of CS by describing the CS reconstruction as a process of interference cancellation. There is also an emphasis on the understanding of the driving factors in applications, including limitations imposed by MRI hardware, by the characteristics of different types of images, and by clinical concerns.

/pdf/compressed-sensing-mri-2wgw41cvre.pdf

Compressed Sensing MRI

Optogenetics in neural systems.

In Vitro Uptake/Imaging Mouse macrophage cells (RAW264) were incubated with ferumoxytol (Feridex), ferumoxtran-10 (Combidex), or graphite/metal core-shell nanocrystals (CN) for 24 hours, each at a concentration of 100 ugFe/ml. After incubation, 5 × 106 cells from each group were scanned by MRI at 1.5 T (GE Healthcare, Milwaukee, WI) to examine cellular uptake of contrast using a standard gradient echo sequence (TR/TE = 100/10, FA = 30, Matrix = 256 × 256, slice thickness = 2.0, FOV = 12 cm). In Vivo Uptake/Imaging FVB mice (N = 5) underwent a carotid-ligation procedure previously shown to produce a macrophage-rich atherosclerotic lesion. Briefly, they were given high fat diet for 4 weeks and then had diabetes induced by 5 daily intraperitoneal injections of streptozotocin. After 2 weeks of diabetes, carotid ligation of the left carotid artery was performed. Two weeks post carotid ligation, mice were given CN-Cy5.5 (8 nmol of Cy5.5) via tail vein and scanned serially over 12–48 hours using the Maestro invivo fluorescent imaging system (CRI, Woburn, MA). After final in vivo imaging, carotid arteries were exposed and both in situ and ex vivo imaging were performed.

/pdf/2105-graphite-metal-core-shell-nanocrystals-as-mri-contrast-2ralam6b78.pdf

2105 Graphite/metal core-shell nanocrystals as MRI contrast agents to detect vascular inflammation

Provided herein are methods for analyzing in vivo a brain circuit. A method of the present disclosure may include using optogenetics to stimulate a first region of a brain of an individual, in conjunction with functional magnetic resonance imaging (fMRI) of different regions of the brain to determine a dynamic functional connection between individual neurons of the first region and a second region of the brain. The method may further include identifying a third region of the brain, the neurons of which region mediate the dynamic functional connection between the first and second regions.

Methods for Functional Brain Circuit Analysis

Obtaining magnetic resonance images (MRI) with high resolution and generating quantitative image-based biomarkers for assessing tissue biochemistry is crucial in clinical and research applications. How- ever, acquiring quantitative biomarkers requires high signal-to-noise ratio (SNR), which is at odds with high-resolution in MRI, especially in a single rapid sequence. In this paper, we demonstrate how super-resolution can be utilized to maintain adequate SNR for accurate quantification of the T2 relaxation time biomarker, while simultaneously generating high- resolution images. We compare the efficacy of resolution enhancement using metrics such as peak SNR and structural similarity. We assess accuracy of cartilage T2 relaxation times by comparing against a standard reference method. Our evaluation suggests that SR can successfully maintain high-resolution and generate accurate biomarkers for accelerating MRI scans and enhancing the value of clinical and research MRI.

Deep Learning Super-Resolution Enables Rapid Simultaneous Morphological and Quantitative Magnetic Resonance Imaging

Methods Normal and stenosis induced white rabbits with body weight of ~4 kg were first catheterized in the ear vein. Through the catheter, 9.6 cc of 5 mM concentration FeCo nanocrystal contrast agent was injected followed by 1 cc of saline injection. Immediately before and after the injection, a small volume covered by a 1 inch custom made surface coil was imaged using spectral-spatial excitation and 3D spiral readout. The spatial resolution was 78 × 78 × 500 um3 with volume coverage of 4 × 4 × 1 cm3. The scan time was 2 min 40 sec for a single volume and the scan was repeated 9 times over 24 min to improve SNR. A whole body volume scan using a fat-saturated 3D SPGR sequence was also performed using a standard GE head coil 1 hour before and after the injection. All the experiments were conducted using a GE 1.5 T EXCITE whole body system with a maximum gradient of 40 mT/m and maximum slew rate of 150 T/m/s.

/pdf/2119-visualization-of-micro-vasculature-using-feco-core-9xt9ib91ey.pdf

2119 Visualization of micro-vasculature using FeCo-core/graphitic-carbon-shell nanocrystals and high-resolution 3D spiral imaging

Examples described herein may provide for pre-triggering imaging scans (e.g. fMRI scans) using an electronic timer synchronized to a stimulation system.

Jin Hyung Lee

Papers

2105 Graphite/metal core-shell nanocrystals as MRI contrast agents to detect vascular inflammation

Methods for Functional Brain Circuit Analysis

Deep Learning Super-Resolution Enables Rapid Simultaneous Morphological and Quantitative Magnetic Resonance Imaging

2119 Visualization of micro-vasculature using FeCo-core/graphitic-carbon-shell nanocrystals and high-resolution 3D spiral imaging

Synchronization devices and methods for synchronizing imaging systems and stimulation systems