The financial support of the Max-Planck Society, the Turkish Ministry of National Education (PhD fellowship to S. G.), and the German Exchange Academic Service (DAAD, PhD fellowship to T. S.) are gratefully acknowledged.

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The authors have nothing to disclose.

הכנת חומר ניגוד MRI dendrimeric דורשת בחירה מתאימה של יחידת monomeric (כלומר, chelator לאלוקים (III)). הם מפחיתים את הרעילות של יון פאראמגנטיים זה, עד כה, מגוון רחב של אציקליות ו chelators macrocyclic לשרת מטרה זו 1-3. בין אלה, chelators DOTA מסוג macrocyclic להחזיק את היציבות התרמודינמית הגבוהה ביות?...

הדמיית תהודה מגנטית (MRI) היא טכניקת הדמיה עוצמה בלתי מייננת בשימוש נרחב מחקר ביו לדיאגנוסטיקה רפואית בשל אופיו פולשנית והניגודיות הרקמות הרכות הפנימית מעולה. שיטות MRI הנפוצות ביותר לנצל את האות המתקבל פרוטונים במים, מתן תמונות ברזולוציה גבוהה ומידע מפורט בתוך הרקמות על בסיס הבדלים בצפיפות של אותות מים. עוצמת האות ואת הספציפיות של ניסויי MRI ניתן לשפר עוד יותר באמצעות סוכנים בניגוד (CA). אלה הם מינים פאראמגנטיים או פאראמגנטי המשפיעים על האורך (T 1) ו רוחבי (T 2) פעמים הרפיה, בהתאמה 1,2. קומפלקסים של גדוליניום lanthanide יון עם polyamino הליגנדים חומצה polycarboxylic הם את רשויות T 1 הנפוץ ביותר. גדוליניום (III) מקצר את ההרפיה T 1זמן של פרוטונים במים, ובכך להגדיל את ניגוד האות בניסויי MRI 3. עם זאת, גדוליניום יוני הוא רעיל; גודלו מדמה את הסידן (II), וזה ברצינות משפיע בסיוע סידן איתות תאי. לכן, chelates אציקליות ו macrocyclic מועסקים לנטרל רעילות זו. הליגנדים multidentate שונים פותחו עד כה, וכתוצאה מכך גדוליניום (III) קומפלקסים עם יציבות תרמודינמית גבוהה אדישות הקינטית 1. אלה המבוססים על cyclen azamacrocycle-membered 12, ב DOTA נגזרת tetracarboxylic שלה בפרט (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) הם חקרו ביותר ויישומי קומפלקסים של המעמד אישורים זו. אף על פי כן, GdDOTA מסוג CAs הם מערכות נמוכות משקל מולקולריים, מוצגות חסרונות מסוימים כגון יעילות ניגודיות נמוכה והפרשה כליות מהר. Macromolecular ו CAs רב-ערכית עשוי להיות פתרון טוב לבעיות אלה 4. מאז CA biodistribution נקבעת בעיקר על ידי גודלם, קאש macromolecular להציג פעמי שמירה עוד הרבה זמן בתוך רקמות. לא פחות חשוב, multivalency של תוצאות סוכנים אלה ריכוז מקומי גדילה של חללית MR monomeric (למשל, מורכבות GdDOTA), באופן משמעותי לשיפור אות MR שנרכשה ואת איכות המדידה. Dendrimers הוא בין הפיגומים המועדפים ביותר לעריכת CAs רב-ערכית עבור MRI 4,5. מקרומולקולות מאוד מסועפות עם גדלים מוגדרים היטב נוטות לתגובות צימוד שונות על פני השטח שלהם. בעבודה זו, אנו מדווחים על הכנה, טיהור, ואפיון של CA dendrimeric עבור MRI המורכב פולי 4 דור (G4) (amidoamine) (Pamam) dendrimer מצמידים chelates דמוי GdDOTA (DCA). אנו מתארים את הסינתזה של נגזר DOTA מגבה הצימוד שלה אל dendrimer Pamam. עם complexation עם אלוקים (III), אפיון physicochemical תקן proceduמחדש של DCA בוצע. לבסוף, ניסויי MRI בוצעו כדי להדגים את היכולת של DCA להפיק תמונות MR עם ניגוד חזק מאלה המתקבלים CAs משקל מולקולרי נמוך.

<table><tbody><tr><td>Cyclen</td><td>CheMatech</td><td>C002</td><td></td></tr><tr><td>&lt;em&gt;tert&lt;/em&gt;-Butyl bromoacetate&amp;nbsp;</td><td>Alfa Aesar</td><td>A14917</td><td></td></tr><tr><td>&lt;em&gt;N,N&lt;/em&gt;-Dimethylformamide</td><td>Fluka</td><td>40248</td><td></td></tr><tr><td>Potassium carbonate</td><td>Sigma-Aldrich</td><td>209619</td><td></td></tr><tr><td>4-(4-Nitrophenyl)butryic acid</td><td>Aldrich</td><td>335339</td><td></td></tr><tr><td>Thionyl chloride&amp;nbsp;</td><td>Acros Organics</td><td>382662500</td><td>Note: Corrosive substance; toxic if inhaled</td></tr><tr><td>Bromine</td><td>Acros Organics</td><td>402841000</td><td>Note: causes severe skin burns, fatal if inhaled&amp;nbsp;</td></tr><tr><td>Diethyl ether</td><td>any source</td><td></td><td></td></tr><tr><td>Sodium sulphate</td><td>Acros Organics</td><td>196640010</td><td></td></tr><tr><td>Chloroform&amp;nbsp;</td><td>VWR Chemicals</td><td>22711.29</td><td></td></tr><tr><td>&lt;em&gt;tert&lt;/em&gt;-Butyl 2,2,2-trichloroacetimidate</td><td>Aldrich</td><td>364789</td><td>Note: flammable substance; irritrant to skin and eyes</td></tr><tr><td>Boron trifluoride etherate</td><td>Acros Organics</td><td>174560250</td><td>48% BF&lt;sub&gt;3&lt;/sub&gt;. Note: Flammable substance; causes skin burns, fatal if inhaled</td></tr><tr><td>Sodium bicarbonate</td><td>Acros Organics</td><td>424270010</td><td></td></tr><tr><td>Ethyl-acetate</td><td>any source</td><td></td><td>For column chromatography</td></tr><tr><td>&lt;em&gt;n&lt;/em&gt;-Hexane</td><td>any source</td><td></td><td>For column chromatography</td></tr><tr><td>Bulb-to-bulb (Kugelrohr) distillation apparatus</td><td>B&amp;uuml;chi</td><td></td><td>Model type: Glass oven B-585</td></tr><tr><td>Silicagel</td><td>Carl Roth GmbH</td><td>P090.2</td><td></td></tr><tr><td>Methanol</td><td>any source</td><td></td><td>For column chromatography</td></tr><tr><td>Dichloromethane&amp;nbsp;</td><td>any source</td><td></td><td>For column chromatography</td></tr><tr><td>Ethanol</td><td>VWR Chemicals</td><td>20821.296</td><td></td></tr><tr><td>Ammonia</td><td>Acros Organics</td><td>428381000</td><td>7 N Solution in Methanol</td></tr><tr><td>Palladium</td><td>Aldrich</td><td>643181</td><td>15% wet</td></tr><tr><td>Hydrogenation apparatus PARR</td><td>PARR Instrument Company</td><td></td><td></td></tr><tr><td>Celite 503</td><td>Aldrich</td><td>22151</td><td></td></tr><tr><td>Sintered glass funnel</td><td>any source</td><td></td><td></td></tr><tr><td>Thiophosgen</td><td>Aldrich</td><td>115150</td><td>Note: irritrant to skin; toxic if inhaled</td></tr><tr><td>Triethylamine</td><td>Alfa Aesar</td><td>A12646</td><td></td></tr><tr><td>Dichloromethane&amp;nbsp;</td><td>Acros Organics</td><td>348460010</td><td>Extra dry&amp;nbsp;</td></tr><tr><td>Magnetic stirrer</td><td>any source</td><td></td><td></td></tr><tr><td>PAMAM G4 Dendrimer</td><td>Andrews ChemService</td><td>AuCS - 297</td><td>10% wt. solution in MeOH</td></tr><tr><td>Lipophylic Sephadex LH-20</td><td>Sigma</td><td>LH20100</td><td></td></tr><tr><td>Thin-layer chromatography plates</td><td>Merck Millipore</td><td>1.05554.0001</td><td></td></tr><tr><td>Formic acid</td><td>VWR Chemicals</td><td>20318.297</td><td></td></tr><tr><td>Lophylizer&amp;nbsp;</td><td>any source</td><td></td><td></td></tr><tr><td>Gadollinium(III) chloride hexahydrate</td><td>Aldrich</td><td>G7532</td><td></td></tr><tr><td>Sodium hydroxide</td><td>Acros Organics</td><td>134070010</td><td></td></tr><tr><td>pH meter</td><td>any source</td><td></td><td></td></tr><tr><td>Ethylenediaminetetraacetic acid disodium salt dihydrate</td><td>Aldrich</td><td>E5134</td><td></td></tr><tr><td>Mass spectrometer (ESI)</td><td>Agilent</td><td></td><td>Ion trap SL 1100&amp;nbsp;</td></tr><tr><td>Acetate buffer</td><td>any source</td><td></td><td>pH 5.8</td></tr><tr><td>Xylenol orange</td><td>Aldrich</td><td>52097</td><td>20 &amp;mu;M in acetate buffer</td></tr><tr><td>Hydrophylic Sephadex G-15</td><td>GE Healthcare</td><td>17-0020-01</td><td></td></tr><tr><td>Amicon Ultra-15 Centrifugal Filter Unit</td><td>Merck Millipore</td><td>UFC900324</td><td>Ultracel-3 membrane (MWCO 3000)</td></tr><tr><td>Centrifuge</td><td>any source</td><td></td><td></td></tr><tr><td>NMR spectrometer&amp;nbsp;</td><td>Bruker</td><td></td><td>Avance III 300 MHz</td></tr><tr><td>Topspin</td><td>Bruker</td><td></td><td>Version 2.1</td></tr><tr><td>Combustion analysis instrument</td><td>EuroVector SpA</td><td></td><td>EuroEA 3000 Elemental Analyser&amp;nbsp;</td></tr><tr><td>MALDI-ToF MS instrument</td><td>Applied Biosystems</td><td></td><td>Voyager-STR</td></tr><tr><td>Deuteriumoxid</td><td>Carl Roth GmbH</td><td>6672.3</td><td></td></tr><tr><td>&lt;em&gt;tert&lt;/em&gt;-Butyl alcohol</td><td>Carl Roth GmbH</td><td>AE16.1</td><td></td></tr><tr><td>Vortex mixer</td><td>any source</td><td></td><td></td></tr><tr><td>Norell NMR tubes</td><td>Deutero GmbH</td><td>507-HP-7</td><td></td></tr><tr><td>NMR coaxial tube</td><td>Deutero GmbH</td><td>coaxialb-5-7</td><td></td></tr><tr><td>DLS instrument</td><td>Malvern</td><td></td><td>Zetasizer Nano ZS</td></tr><tr><td>0.20 &amp;mu;m PTFE filter&amp;nbsp;</td><td>Carl Roth GmbH</td><td>KC94.1</td><td></td></tr><tr><td>HEPES</td><td>Fisher BioReagents</td><td>BP310</td><td></td></tr><tr><td>Plastic tube vials</td><td>any source</td><td></td><td></td></tr><tr><td>Dotarem</td><td>Guerbet</td><td></td><td>NDC 67684-2000-1</td></tr><tr><td>MRI scanner</td><td>Bruker</td><td></td><td>BioSpec 70/30 USR magnet (7 T). Note: potential hazards related to high magnetic fields</td></tr><tr><td>RF coil</td><td>Bruker</td><td></td><td>Dual frequency volume coil (RF RES 300 1H/19F 075/040 LIN/LIN TR)</td></tr><tr><td>Paravision (software)</td><td>Bruker</td><td></td><td>Version 5.1</td></tr></tbody></table>

preparation and in vitro characterization of dendrimer-based contrast agents for magnetic resonance imaging

מתחמי פאראמגנטיים של גדוליניום (III) עם אציקליות או chelates macrocyclic הם סוכנים בניגוד הנפוץ ביותר (CA) עבור הדמיה בתהודה מגנטית (MRI). מטרתם היא לשפר את שיעור הרפיה של פרוטונים מים ברקמות, ובכך להגדיל את הניגוד התמונה MR ואת הספציפיות של מדידות MRI. סוכנים בניגוד נוכחיים קליני שאושרו הם מולקולות משקל מולקולארי נמוכות, נמחקות במהירות מהגוף. שימוש dendrimers כנושאי chelators פאראמגנטיים יכול למלא תפקיד חשוב בהתפתחות העתידית של סוכנים בניגוד MRI יעילים יותר. באופן ספציפי, העלייה בריכוז המקומי של תוצאות מיני פאראמגנטיים ב ניגוד אות גבוה. יתר על כן, CA זה מספק זמן שמירת רקמות כבר בשל המשקל והגודל מולקולריים גבוהים. הנה, אנחנו מדגימים הליך נוח לעריכת חומר ניגוד MRI macromolecular מבוסס על פולי (amidoamine) (Pamam) dendrimers עם monomacrochelators DOTA מהסוג מחזורי (DOTA - 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate). היחידה chelating צורף על ידי ניצול תגובתיות של isothiocyanate (NCS) הקבוצה כלפי קבוצות משטח אמין של dendrimer Pamam להקים גשרים thiourea. מוצרי Dendrimeric היו מטוהרים ונותחו באמצעות ספקטרוסקופיית תהודה מגנטית גרעינית, ספקטרומטריית מסה, ואת ניתוח יסודי. לבסוף, ברזולוציה גבוהה תמונות MR הוקלטו ניגודי האות המתקבל מן dendrimeric המוכן וסוכני monomeric הזמינים המסחרי הושוו.

הכנת DCA מורכב משני שלבים: 1) סינתזה של chelator DOTA מסוג monomeric (איור 1) ו -2) צימוד של chelator עם dendrimer G4 Pamam והכנת הבאות של הקב&quot;ה dendrimeric (III) מורכבים (איור 2) . בשלב הראשון, chelator cyclen המבוסס DOTA מהסוג המכיל ארבע חומצות קרבוקסיליות וקבוצה מאו...

Watch this Scientific Journal Video about Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging at JoVE.com

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging

פרוטוקול זה מתאר את ההכנה ואפיון של תהודה מגנטית dendrimeric חומר ניגוד (MRI) שנושא chelates macrocyclic המבוסס cyclen תיאום יוני גדוליניום פאראמגנטיים. בסדרת ניסויי MRI במבחנה, סוכן זה מיוצר אות MRI מוגברת בהשוואה האנלוגית monomeric הזמין המסחרי.

הכנה<em&gt; במבחנה</em&gt; אפיון חומרי ניגוד מבוססי dendrimer עבור דימות תהודה מגנטית

Paramagnetic complexes of gadolinium(III) with acyclic or macrocyclic chelates are the most commonly used contrast agents (CAs) for magnetic resonance ...

preparation-vitro-characterization-dendrimer-based-contrast-agents

Research

JoVE Journal

Chemistry

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging

9.8K Views.  Max Planck Institute for Biological Cybernetics.  פרוטוקול זה מתאר את ההכנה ואפיון של תהודה מגנטית dendrimeric חומר ניגוד (MRI) שנושא chelates macrocyclic המבוסס cyclen תיאום יוני גדוליניום פאראמגנטיים. בסדרת ניסויי MRI במבחנה, סוכן זה מיוצר אות MRI מוגברת בהשוואה האנלוגית monomeric הזמין המסחרי. 

Video: Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

For aqueous based supramolecular polymers, the simultaneous control over shape, size and stability is very difficult1. At the same time, the ability to do so is highly important in view of a number of applications in functional soft matter including electronics, biomedical engineering, and sensors. In the past, successful strategies to control the size and shape of supramolecular polymers typically focused on the use of templates2,3, end cappers4 or selective solvent techniques5. 
Here we disclose a strategy based on self-assembling discotic amphiphiles that leads to the control over stack length and shape of ordered, chiral columnar aggregates. By balancing electrostatic repulsive interactions on the hydrophilic rim and attractive non-covalent forces within the hydrophobic core of the polymerizing building block, we manage to create small and discrete spherical objects6,7. Increasing the salt concentration to screen the charges induces a sphere-to-rod transition. Intriguingly, this transition is expressed in an increase of cooperativity in the temperature-dependent self-assembly mechanism, and more stable aggregates are obtained. 
For our study we select a benzene-1,3,5-tricarboxamide (BTA) core connected to a hydrophilic metal chelate via a hydrophobic, fluorinated L-phenylalanine based spacer (Scheme 1). The metal chelate selected is a Gd(III)-DTPA complex that contains two overall remaining charges per complex and necessarily two counter ions. The one-dimensional growth of the aggregate is directed by &pi;-&pi; stacking and intermolecular hydrogen bonding. However, the electrostatic, repulsive forces that arise from the charges on the Gd(III)-DTPA complex start limiting the one-dimensional growth of the BTA-based discotic once a certain size is reached. At millimolar concentrations the formed aggregate has a spherical shape and a diameter of around 5 nm as inferred from 1H-NMR spectroscopy, small angle X-ray scattering, and cryogenic transmission electron microscopy (cryo-TEM). The strength of the electrostatic repulsive interactions between molecules can be reduced by increasing the salt concentration of the buffered solutions. This screening of the charges induces a transition from spherical aggregates into elongated rods with a length &gt; 25 nm. Cryo-TEM allows to visualise the changes in shape and size. In addition, CD spectroscopy permits to derive the mechanistic details of the self-assembly processes before and after the addition of salt. Importantly, the cooperativity -a key feature that dictates the physical properties of the produced supramolecular polymers- increases dramatically upon screening the electrostatic interactions. This increase in cooperativity results in a significant increase in the molecular weight of the formed supramolecular polymers in water.

The goal of this experiment is to determine and control the size, shape and stability of self-assembled discotic amphiphiles in water. For aqueous based supramolecular polymers such level of control is very difficult. We apply a strategy using both repulsive and attractive interactions. The experimental techniques applied to characterize this system are broadly applicable.

שליטה על גודל, צורה ויציבות של פולימרים מולקולריים במים

For aqueous based supramolecular polymers, the simultaneous control over shape, size and stability is very difficult1. At the same time, the ability to do ...

Engineering

Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring 

Nanomedications can be carried by blood borne monocyte-macrophages into the reticuloendothelial system (RES; spleen, liver, lymph nodes) and to end organs. The latter include the lung, RES, and brain and are operative during human immunodeficiency virus type one (HIV-1) infection. Macrophage entry into tissues is notable in areas of active HIV-1 replication and sites of inflammation. In order to assess the potential of macrophages as nanocarriers, superparamagnetic iron-oxide and/or drug laden particles coated with surfactants were parenterally injected into HIV-1 encephalitic mice. This was done to quantitatively assess particle and drug biodistribution. Magnetic resonance imaging (MRI) test results were validated by histological coregistration and enhanced image processing. End organ disease as typified by altered brain histology were assessed by MRI. The demonstration of robust migration of nanoformulations into areas of focal encephalitis provides '"proof of concept" for the use of advanced bioimaging techniques to monitor macrophage migration. Importantly, histopathological aberrations in brain correlate with bioimaging parameters making the general utility of MRI in studies of cell distribution in disease feasible. We posit that using such methods can provide a real time index of disease burden and therapeutic efficacy with translational potential to humans.

Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring

Bioimaging methods used to assess cell biodistribution of nanoparticles are applicable for therapeutic and diagnostic monitoring of nanoformulated compounds. The methods described herein are sensitive and specific when assessed by histological coregistration. The methodologies provide a translational pathway from rodent to human applications.

Bioimaging רשום של ננו לניטור האבחון והטיפול

Nanomedications can be carried by blood borne monocyte-macrophages into the reticuloendothelial system (RES; spleen, liver, lymph nodes) and to end ...

Bioengineering

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

The development of fluorescent indicators represented a revolution for life sciences. Genetically encoded and synthetic fluorophores with sensing abilities allowed the visualization of biologically relevant species with high spatial and temporal resolution. Synthetic dyes are of particular interest thanks to their high tunability and the wide range of measureable analytes. However, these molecules suffer several limitations related to small molecule behavior (poor solubility, difficulties in targeting, often no ratiometric imaging allowed). In this work we introduce the development of dendrimer-based sensors and present a procedure for pH measurement in vitro, in living cells and in vivo. We choose dendrimers as ideal platform for our sensors for their many desirable properties (monodispersity, tunable properties, multivalency) that made them a widely used scaffold for several biomedical devices. The conjugation of fluorescent pH indicators to the dendrimer scaffold led to an enhancement of their sensing performances. In particular dendrimers exhibit reduced cell leakage, improved intracellular targeting and allow ratiometric measurements. These novel sensors were successfully employed to measure pH in living HeLa cells and in vivo in mouse brain.

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Fluorescence sensors are powerful tools in life science. Here we describe a methodology to synthesize and use dendrimer-based fluorescent sensors to measure pH in living cells and in vivo. The dendritic scaffold enhances the properties of conjugated fluorescent dyes leading to improved sensing properties.

סינתזה, משלוח נייד ו<em&gt; בvivo</em&gt; יישום של חיישני pH מבוססי dendrimer

The development of  fluorescent indicators represented a revolution for life sciences. Genetically  encoded and synthetic fluorophores with sensing ...

In vitro Labeling of Human Embryonic Stem Cells for Magnetic Resonance Imaging

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of the predominant imaging modalities to assess the restoration of the injured myocardium. Furthermore, ex-vivo labeling agents, such as iron-oxide nanoparticles, have been employed to track and localize the transplanted stem cells. However, this method does not monitor a fundamental cellular biology property regarding the viability of transplanted cells. It has been known that manganese chloride (MnCl2) enters the cells via voltage-gated calcium (Ca2+) channels when the cells are biologically active, and accumulates intracellularly to generate T1 shortening effect. Therefore, we suggest that manganese-guided MRI can be useful to monitor cell viability after the transplantation of hESC into the myocardium.
In this video, we will show how to label hESC with MnCl2 and how those cells can be clearly seen by using MRI in vitro. At the same time, biological activity of Ca2+-channels will be modulated utilizing both Ca2+-channel agonist and antagonist to evaluate concomitant signal changes.

In this video, we are showing how to label human embryonic stem cells (hESC) with manganese chloride (MnCl2) which can enter cells via voltage-gated calcium channels when the cells are biologically active. Additionally, we show the use of MnCl2 as cellular MRI contrast agent to determine the in vitro viability of hESC.

ב סימון במבחנה של בתאי גזע עובריים אנושיים עבור דימות תהודה מגנטית

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of ...

Biology

Monitoring Dendritic Cell Migration using 19F / 1H Magnetic Resonance Imaging

Continuous advancements in noninvasive imaging modalities such as magnetic resonance imaging (MRI) have greatly improved our ability to study physiological or pathological processes in living organisms. MRI is also proving to be a valuable tool for capturing transplanted cells in vivo. Initial cell labeling strategies for MRI made use of contrast agents that influence the MR relaxation times (T1, T2, T2*) and lead to an enhancement (T1) or depletion (T2*) of signal where labeled cells are present. T2* enhancement agents such as ultrasmall iron oxide agents (USPIO) have been employed to study cell migration and some have also been approved by the FDA for clinical application. A drawback of T2* agents is the difficulty to distinguish the signal extinction created by the labeled cells from other artifacts such as blood clots, micro bleeds or air bubbles. In this article, we describe an emerging technique for tracking cells in vivo that is based on labeling the cells with fluorine (19F)-rich particles. These particles are prepared by emulsifying perfluorocarbon (PFC) compounds and then used to label cells, which subsequently can be imaged by 19F MRI. Important advantages of PFCs for cell tracking in vivo include (i) the absence of carbon-bound 19F in vivo, which then yields background-free images and complete cell selectivityand(ii) the possibility to quantify the cell signal by 19F MR spectroscopy.

Monitoring Dendritic Cell Migration using 19F / 1H Magnetic Resonance Imaging

Tracking of cells using MRI has gained remarkable attention in the past years. This protocol describes the labeling of dendritic cells with fluorine (19F)-rich particles, the in vivo application of these cells, and monitoring the extent of their migration to the draining lymph node with 19F/1H MRI and 19F MRS.

נדידת תאים דנדריטים ניטור באמצעות<sup&gt; 19</sup&gt; F /<sup&gt; 1</sup&gt; H דימות תהודה מגנטית

Continuous  advancements in noninvasive imaging modalities such as magnetic resonance  imaging (MRI) have greatly improved our ability to study ...

Immunology and Infection

MR Molecular Imaging of Prostate Cancer with a Small Molecular CLT1 Peptide Targeted Contrast Agent

Tumor extracellular matrix has abundance of cancer related proteins that can be used as biomarkers for cancer molecular imaging. In this work, we demonstrated effective MR cancer molecular imaging with a small molecular peptide targeted Gd-DOTA monoamide complex as a targeted MRI contrast agent specific to clotted plasma proteins in tumor stroma. We performed the experiment of evaluating the effectiveness of the agent for non-invasive detection of prostate tumor with MRI in a mouse orthotopic PC-3 prostate cancer model. The targeted contrast agent was effective to produce significant tumor contrast enhancement at a low dose of 0.03 mmol Gd/kg. The peptide targeted MRI contrast agent is promising for MR molecular imaging of prostate tumor.

To demonstrate MR cancer molecular imaging with a small peptide targeted MRI contrast agent specific to clotted plasma proteins in tumor stroma in a mouse prostate cancer model.

MR הדמיה המולקולרית של סרטן הערמונית עם חומר ניגוד ממוקד המולקולרי קטן CLT1 פפטיד

Tumor extracellular  matrix has abundance of cancer related proteins that can be used as biomarkers  for cancer molecular imaging. In this work,  we ...

Medicine

Biofunctionalized Prussian Blue Nanoparticles for Multimodal Molecular Imaging Applications

Multimodal, molecular imaging allows the visualization of biological processes at cellular, subcellular, and molecular-level resolutions using multiple, complementary imaging techniques. These imaging agents facilitate the real-time assessment of pathways and mechanisms in vivo, which enhance both diagnostic and therapeutic efficacy. This article presents the protocol for the synthesis of biofunctionalized Prussian blue nanoparticles (PB NPs) - a novel class of agents for use in multimodal, molecular imaging applications. The imaging modalities incorporated in the nanoparticles, fluorescence imaging and magnetic resonance imaging (MRI), have complementary features. The PB NPs possess a core-shell design where gadolinium and manganese ions incorporated within the interstitial spaces of the PB lattice generate MRI contrast, both in T1 and T2-weighted sequences. The PB NPs are coated with fluorescent avidin using electrostatic self-assembly, which enables fluorescence imaging. The avidin-coated nanoparticles are modified with biotinylated ligands that confer molecular targeting capabilities to the nanoparticles. The stability and toxicity of the nanoparticles are measured, as well as their MRI relaxivities. The multimodal, molecular imaging capabilities of these biofunctionalized PB NPs are then demonstrated by using them for fluorescence imaging and molecular MRI in vitro.

This protocol describes the synthesis of biofunctionalized Prussian blue nanoparticles and their use as multimodal, molecular imaging agents. The nanoparticles have a core-shell design where gadolinium or manganese ions within the nanoparticle core generate MRI contrast. The biofunctional shell contains fluorophores for fluorescence imaging and targeting ligands for molecular targeting.

Biofunctionalized הכחול פרוסים חלקיקים ליישומי הדמיה מולקולריים Multimodal

Multimodal, molecular imaging allows the visualization of biological processes at cellular, subcellular, and molecular-level resolutions using multiple, ...

In vivo 19F MRI for Cell Tracking

In vivo 19F MRI allows quantitative cell tracking without the use of ionizing radiation. It is a noninvasive technique that can be applied to humans. Here, we describe a general protocol for cell labeling, imaging, and image processing. The technique is applicable to various cell types and animal models, although here we focus on a typical mouse model for tracking murine immune cells. The most important issues for cell labeling are described, as these are relevant to all models. Similarly, key imaging parameters are listed, although the details will vary depending on the MRI system and the individual setup. Finally, we include an image processing protocol for quantification. Variations for this, and other parts of the protocol, are assessed in the Discussion section. Based on the detailed procedure described here, the user will need to adapt the protocol for each specific cell type, cell label, animal model, and imaging setup. Note that the protocol can also be adapted for human use, as long as clinical restrictions are met.

In vivo 19F MRI for Cell Tracking

We describe a general protocol for in vivo cell tracking using MRI in a mouse model with ex vivo labeled cells. A typical protocol for cell labeling, image acquisition processing and quantification is included.

בF-MRI 19 vivo למעקב סלולרי

In vivo 19F MRI allows quantitative cell tracking without the use of ionizing radiation. It is a noninvasive technique that can be applied to humans. ...

<meta charset="utf8"></head><body>ננו-חלקיקים של תחמוצת ברזל למתן טיפול מונחה דמיון בגליובלסטומה מורין

Nanoparticle Delivery of an Oligonucleotide Payload in a Glioblastoma Multiforme Animal Model

Glioblastoma multiforme (GBM) is the most common and aggressive form of primary brain malignancy for which there is no cure. The blood-brain barrier is a significant hurdle in the delivery of therapies to GBM. Reported here is an image-guided, iron oxide-based therapeutic delivery nano platform capable of bypassing this physiological barrier by virtue of size and accumulating in the tumor region, delivering its payload. This 25 nm nano platform consists of crosslinked dextran-coated iron oxide nanoparticles labeled with Cy5.5 fluorescent dye and containing antisense oligonucleotide as a payload. The magnetic iron oxide core enables tracking of the nanoparticles through in vivo magnetic resonance imaging, while Cy5.5 dye allows tracking by optical imaging. This report details the monitoring of the accumulation of this nanoparticle platform (termed MN-anti-miR10b) in orthotopically implanted glioblastoma tumors following intravenous injection. In addition, it provides insight into the in vivo delivery of RNA oligonucleotides, a problem that has hampered the translation of RNA therapeutics into the clinic.

<meta charset="utf8"></head><body>מחבר זרקור: טיפולים חדשניים בסרטן עם ננו-חלקיקים של תחמוצת ברזל לטיפול בגליובלסטומה

The blood-brain barrier is a significant hurdle in the delivery of therapies for glioblastoma, a disease for which there is no cure. Here, we report an in vivo image-guided iron oxide therapeutic nano platform that can bypass this physiological barrier by virtue of size and accumulate in the tumor.

העברת ננו-חלקיקים של מטען אוליגונוקלאוטיד במודל בעלי חיים רב-צורניים מסוג גליובלסטומה

Glioblastoma multiforme (GBM) is the most common and aggressive form of primary brain malignancy for which there is no cure. The blood-brain barrier is a ...

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שליטה על גודל, צורה ויציבות של פולימרים מולקולריים במים

Bioimaging רשום של ננו לניטור האבחון והטיפול

סינתזה, משלוח נייד ו

ב סימון במבחנה של בתאי גזע עובריים אנושיים עבור דימות תהודה מגנטית

נדידת תאים דנדריטים ניטור באמצעות

MR הדמיה המולקולרית של סרטן הערמונית עם חומר ניגוד ממוקד המולקולרי קטן CLT1 פפטיד

Biofunctionalized הכחול פרוסים חלקיקים ליישומי הדמיה מולקולריים Multimodal

בF-MRI ¹⁹ vivo למעקב סלולרי

העברת ננו-חלקיקים של מטען אוליגונוקלאוטיד במודל בעלי חיים רב-צורניים מסוג גליובלסטומה

העברת ננו-חלקיקים של מטען אוליגונוקלאוטיד במודל בעלי חיים רב-צורניים מסוג גליובלסטומה