החוקרים בתודה להכיר פרופ &#39;אנדריאה ארמני באוניברסיטה של ​​דרום קליפורניה על התמיכה בתקופה זו פותח פרוטוקול. מימון הפיתוח הראשוני של העבודה זה סופק על ידי הקרן הלאומית למדע [085281 ו 1028440] לבין המכון הלאומי לבריאות בארה&quot;ב NIH דרך ניו תוכנית של מנהל פרס ממציא [1DP2OD007391-01]. מידע נוסף זמין בכתובת <a href="http://web.missouri.edu/~hunthk/" target="_blank">http://web.missouri.edu/ hunthk ~ /</a> .

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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Label-free+technologies+for+quantitative+multiparameter+biological+analysis.">Label-free technologies for quantitative multiparameter biological analysis.</a> Analytical and Bioanalytical Chemistry. 394, 121-135 (2009).</li><li>Hunt, H. K., Soteropulos, C., Armani, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioconjugation+Strategies+for+Microtoroidal+Optical+Resonators.">Bioconjugation Strategies for Microtoroidal Optical Resonators.</a> Sensors. 10, 9317-9336 (2010).</li><li>Kalia, J., Raines, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+Bioconjugation.">Advances in Bioconjugation.</a> Curr. Org. Chem. 14, 138-147 (2010).</li><li>Matsko, A. B., Savchenkov, A. A., Strekalov, D., Ilchenko, V. S., Maleki, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+of+Applications+of+Whispering-Gallery+Mode+Resonators+in+Photonics+and+Nonlinear+Optics.">Review of Applications of Whispering-Gallery Mode Resonators in Photonics and Nonlinear Optics.</a> IPN Progress Report. , 42-162 (2005).</li><li>Armani, A. M., Kulkarni, R. P., Fraser, S. E., Flagan, R. C., Vahala, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Label-free,+single-molecule+detection+with+optical+microcavities.">Label-free, single-molecule detection with optical microcavities.</a> Science. 317, 783-787 (2007).</li><li>Zhu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On-chip+single+nanoparticle+detection+and+sizing+by+mode+splitting+in+an+ultrahigh-Q+microresonator.">On-chip single nanoparticle detection and sizing by mode splitting in an ultrahigh-Q microresonator.</a> Nat. Photon. 4, 122-122 (2010).</li><li>Armani, D. K., Kippenberg, T. J., Spillane, S. M., Vahala, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultra-high-Q+toroid+microcavity+on+a+chip.">Ultra-high-Q toroid microcavity on a chip.</a> Nature. 421, 925-928 (2003).</li><li>Vollmer, F., Arnold, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whispering-gallery-mode+biosensing:+label-free+detection+down+to+single+molecules.">Whispering-gallery-mode biosensing: label-free detection down to single molecules.</a> Nat. Methods. 5, 591-596 (2008).</li><li>Vollmer, F., Arnold, S., Keng, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+virus+detection+from+the+reactive+shift+of+a+whispering+gallery+mode.">Single virus detection from the reactive shift of a whispering gallery mode.</a> Proc. Natl. Acad. Sci. U.S.A. 105, 20701-20704 (2008).</li><li>Hunt, H. K., Armani, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recycling+microcavity+optical+biosensors.">Recycling microcavity optical biosensors.</a> Opt. Lett. 36, 1092-1094 (2011).</li><li>Soteropulos, C. E., Hunt, H. K., Armani, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+binding+kinetics+using+whispering+gallery+mode+microcavities.">Determination of binding kinetics using whispering gallery mode microcavities.</a> Appl. Phys. Lett. 99, 103703-103703 (2011).</li></ol>

אין ניגוד עניינים הצהיר.

כפי שמתואר בפרוטוקולים, יצרנו פלטפורמה הדיור שבו להעביר סיליקה microspheres מרגליהן לאורך כל תהליך functionalization. פלטפורמה זו הדיור נוצר כפתרון זיהום פני השטח ואת הנזק כתוצאה microsphere לבוא במגע עם קירות מכולות שונים המשמשים בתהליך functionalization. הבנו את הקושי העיקרי נבע מן הזמן מצרף...

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> שם מגיב </td><td> חברה </td><td> מספר קטלוגי </td><td> תגובות </td></tr><tr><td> מתנול </td><td> דיג </td><td> 67-56-1 </td><td> ACS כיתה </td></tr><tr><td> חומצה גופרתית </td><td> דיג </td><td> 8014-95-7 </td><td> רותחת </td></tr><tr><td> מי חמצן </td><td> דיג </td><td> 7722-84-1 </td><td> 30 wt% </td></tr><tr><td> Aminopropyltrimethoxysilane </td><td> דיג </td><td> 13822-56-5 </td><td></td></tr><tr><td> שירותי הבריאות, ביוטין EZ מקשר </td><td> לנקב </td><td> 20217 </td><td></td></tr><tr><td> Dimethylsulfoxide </td><td> דיג </td><td> 67-68-5 </td><td> נטול מים </td></tr><tr><td> Fluorescein Isothiocyanate </td><td> לנקב </td><td> 46425 </td><td></td></tr><tr><td> פוספט שנאגרו מלוחים </td><td> דיג </td><td> 7647-14-5 </td><td> אבקת להתרכז </td></tr><tr><td> סודיום ביקרבונט מאגר </td><td> דיג </td><td> NC0099321 </td><td></td></tr><tr><td> טקסס אדום - Avidin המצומד </td><td> לנקב </td><td> A820 </td><td></td></tr><tr><td> סיב אופטי </td><td> ניופורט </td><td> F-SC </td><td></td></tr><tr><td> סיבים חשפנית </td><td> כלי סיבים מכירות </td><td> NN-175 </td><td> ללא ניק 175 אום חשפנית </td></tr><tr><td> Kimwipes </td><td> דיג </td><td> 06666A </td><td></td></tr><tr><td> סיבים חשופים קליבר </td><td> Ilsintech </td><td> CL-03A </td><td></td></tr><tr><td> מיקרוסקופ זכוכית שקופיות </td><td> דיג </td><td> 12-550B </td><td></td></tr><tr><td> בקבוקוני פלסטיק פוליפרופילן </td><td> דיג </td><td> 03-341-75A </td><td> 60 מ&quot;ל, צירים שווי </td></tr><tr><td> דוגרים Rocker </td><td&gt; VWR </td><td> 12620-910 </td><td></td></tr><tr><td> אבק תא ייבוש </td><td> דיג </td><td> 08-594 15 ב- </td><td></td></tr></tbody></table>

attaching biological probes to silica optical biosensors using silane coupling agents

על מנת ממשק עם סביבות ביולוגיים, פלטפורמות biosensor, כגון מערכת Biacore הפופולרי (מבוסס על משטח Plasmon תהודה (SPR) טכניקה), לעשות שימוש בטכניקות שונות שינוי פני השטח, זה יכול, למשל, למנוע עכירות פני השטח, לכוון את hydrophobicity / hydrophilicity של פני השטח, להתאים למגוון רחב של סביבות אלקטרוניים, לעתים קרובות ביותר, לגרום הספציפיות לקראת היעד של עניין. 1-5 טכניקות אלו להרחיב את הפונקציונליות של biosensors אחרת רגישים מאוד של העולם האמיתי יישומים בסביבות מורכבות, כגון כמו דם, שתן, וניתוח שפכים. 2,6-7 בעוד פלטפורמות biosensing מסחריים, כגון Biacore, יש להבין היטב, טכניקות סטנדרטיות לביצוע שינויים מסוג זה על פני השטח, טכניקות אלה לא תורגמו בצורה סטנדרטית אחרת תווית פלטפורמות biosensing בחינם, כמו לוחשים מצב גלריה (WGM) תהודה אופטי. 8-9 &lt;<html> / P&gt; תהודה WGM אופטיים מייצגים טכנולוגיה מבטיחה לביצוע ללא תווית זיהוי של מגוון רחב של מינים ב נמוך במיוחד בריכוזים 6,10-12 רגישות גבוהה של פלטפורמות אלה הוא תוצאה של אופטיקה גיאומטריות הייחודיות שלהם. WGM תהודה אופטי להגביל במחזור . אור, תדרים מסוימים תהודה אינטגרלי 13 כמו פלטפורמות SPR, בתחום האופטי אינו מוגבל לחלוטין למכשיר חיישן, אבל evanesces; זה &quot;זנב חלוף&quot; אז יכול לקיים אינטראקציה עם המין בתוך הסביבה. אינטראקציה זו גורמת מקדם השבירה יעילה של השדה האופטי לשנות, וכתוצאה מכך קל, אבל ניתן לגילוי, שינוי תדר התהודה של ההתקן. כי בתחום האופטי מסתובב, הוא יכול לתקשר עם הסביבה פעמים רבות, וכתוצאה מכך הגברה פנימית של האות, ואת רגישויות גבוהות מאוד לשינויים קלים בסביבה. 2,14-15 אוהל &quot;&gt; כדי לבצע איתור ממוקד בסביבות מורכבות, פלטפורמות אלה חייבים להיות יחד עם מולקולת בדיקה (בדרך כלל 1 1/2 של זוג מחייב, למשל נוגדנים / אנטיגנים) באמצעות שינוי פני השטח. 2 למרות תהודה WGM אופטיים יכול להיות מפוברק הגיאומטריות כמה מן מגוון רחב של מערכות גשמי, microsphere סיליקה היא הנפוצה ביותר. microspheres אלו מיוצרים בדרך כלל על קצה של סיב אופטי, המספק &quot;גזע&quot;, שבאמצעותה microspheres ניתן לטפל במהלך הניסויים functionalization זיהוי. משטח chemistries סיליקה רשאי להיות מיושם לצרף מולקולות בדיקה כדי השטח שלהם, עם זאת, טכניקות מסורתיות שנוצר על מצעים מישוריים הם בדרך כלל לא מספיק אלה תלת ממדי מבנים, כמו כל שינוי פני השטח של microspheres (אבק, זיהום, ליקויים פני השטח, ציפוי אחיד) יכולות להיות חמורות, השלכות שליליות על יכולת הגילוי שלהן. הנה, אנחנו מדגימים את הגישה קלילעבור functionalization את פני השטח של microsphere תהודה סיליקה WGM אופטי באמצעות סוכני צימוד silane לגשר על פני אורגניים ואיכות הסביבה הביולוגית, על ידי הצמדת ביוטין אל פני השטח סיליקה. 8,16 למרות שאנו משתמשים microsphere סיליקה תהודה WGM כמערכת חיישן בדוח זה, הפרוטוקולים הם כלליים וניתן להשתמש functionalize את פני השטח של כל מכשיר עם סיליקה ביוטין.

Watch this Scientific Journal Video about Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents at JoVE.com

Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents

Biosensors ממשק עם סביבות מורכבות ביולוגיות ולבצע איתור ממוקד על ידי שילוב של חיישנים רגישים מאוד עם בדיקות ספציפיות ביותר המחוברים חיישן באמצעות שינוי פני השטח. הנה, אנחנו מדגימים functionalization פני השטח של חיישנים אופטיים עם סיליקה ביוטין באמצעות סוכני צימוד silane לגשר על חיישן את הסביבה הביולוגית.

הוספת בדיקות ביולוגיות Biosensors סיליקה אופטי באמצעות סוכני צימוד silane

In order to interface with biological environments, biosensor platforms, such as the popular Biacore system (based on the Surface Plasmon Resonance (SPR) ...

attaching-biological-probes-to-silica-optical-biosensors-using-silane

Research

JoVE Journal

Bioengineering

12.8K Views.  University of Missouri. Biosensors ממשק עם סביבות מורכבות ביולוגיות ולבצע איתור ממוקד על ידי שילוב של חיישנים רגישים מאוד עם בדיקות ספציפיות ביותר המחוברים חיישן באמצעות שינוי פני השטח. הנה, אנחנו מדגימים functionalization פני השטח של חיישנים אופטיים עם סיליקה ביוטין באמצעות סוכני צימוד silane לגשר ע...

Video: Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents

Engineering Biological-Based Vascular Grafts Using a Pulsatile Bioreactor

Much effort has been devoted to develop and advance the methodology to regenerate functional small-diameter arterial bypasses. In the physiological environment, both mechanical and chemical stimulation are required to maintain the proper development and functionality of arterial vessels1,2.
Bioreactor culture systems developed by our group are designed to support vessel regeneration within a precisely controlled chemo-mechanical environment mimicking that of native vessels. Our bioreactor assembly and maintenance procedures are fairly simple and highly repeatable3,4. Smooth muscle cells (SMCs) are seeded onto a tubular polyglycolic acid (PGA) mesh that is threaded over compliant silicone tubing and cultured in the bioreactor with or without pulsatile stimulation for up to 12 weeks. There are four main attributes that distinguish our bioreactor from some predecessors. 1) Unlike other culture systems that simulate only the biochemical surrounding of native blood vessels, our bioreactor also creates a physiological pulsatile environment by applying cyclic radial strain to the vessels in culture. 2) Multiple engineered vessels can be cultured simultaneously under different mechanical conditions within a controlled chemical environment. 3) The bioreactor allows a mono layer of endothelial cells (EC) to be easily coated onto the luminal side of engineered vessels for animal implantation models. 4) Our bioreactor can also culture engineered vessels with different diameter size ranged from 1 mm to 3 mm, saving the effort to tailor each individual bioreactor to fit a specific diameter size. 
The engineered vessels cultured in our bioreactor resemble native blood vessels histologically to some degree. Cells in the vessel walls express mature SMC contractile markers such as smooth muscle myosin heavy chain (SMMHC)3. A substantial amount of collagen is deposited within the extracellular matrix, which is responsible for ultimate mechanical strength of the engineered vessels5. Biochemical analysis also indicates that collagen content of engineered vessels is comparable to that of native arteries6. Importantly, the pulsatile bioreactor has consistently regenerated vessels that exhibit mechanical properties that permit successful implantation experiments in animal models3,7. Additionally, this bioreactor can be further modified to allow real-time assessment and tracking of collagen remodeling over time, non-invasively, using a non-linear optical microscopy (NLOM)8. To conclude, this bioreactor should serve as an excellent platform to study the fundamental mechanisms that regulate the regeneration of functional small-diameter vascular grafts.

Our group has developed a bioreactor culture system that mimics the physiological pulsatile stresses of the cardiovascular system to regenerate implantable small-diameter vascular grafts.

הנדסה ביולוגית המבוססת דם שתלי שימוש bioreactor pulsatile

Much effort has been devoted to develop and advance the methodology to regenerate functional small-diameter arterial bypasses. In the physiological ...

Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic valve leaflets are composed of interstitial cells suspended within an extracellular matrix (ECM) and are lined with an endothelial cell monolayer. The valve withstands a harsh, dynamic environment and is constantly exposed to shear, flexion, tension, and compression. Research has shown calcific lesions in diseased valves occur in areas of high mechanical stress as a result of endothelial disruption or interstitial matrix damage1-3. Hence, it is not surprising that epidemiological studies have shown high blood pressure to be a leading risk factor in the onset of aortic valve disease4. 
The only treatment option currently available for valve disease is surgical replacement of the diseased valve with a bioprosthetic or mechanical valve5. Improved understanding of valve biology in response to physical stresses would help elucidate the mechanisms of valve pathogenesis. In turn, this could help in the development of non-invasive therapies such as pharmaceutical intervention or prevention. Several bioreactors have been previously developed to study the mechanobiology of native or engineered heart valves6-9. Pulsatile bioreactors have also been developed to study a range of tissues including cartilage10, bone11 and bladder12. The aim of this work was to develop a cyclic pressure system that could be used to elucidate the biological response of aortic valve leaflets to increased pressure loads. 
The system consisted of an acrylic chamber in which to place samples and produce cyclic pressure, viton diaphragm solenoid valves to control the timing of the pressure cycle, and a computer to control electrical devices. The pressure was monitored using a pressure transducer, and the signal was conditioned using a load cell conditioner. A LabVIEW program regulated the pressure using an analog device to pump compressed air into the system at the appropriate rate. The system mimicked the dynamic transvalvular pressure levels associated with the aortic valve; a saw tooth wave produced a gradual increase in pressure, typical of the transvalvular pressure gradient that is present across the valve during diastole, followed by a sharp pressure drop depicting valve opening in systole. The LabVIEW program allowed users to control the magnitude and frequency of cyclic pressure. The system was able to subject tissue samples to physiological and pathological pressure conditions. This device can be used to increase our understanding of how heart valves respond to changes in the local mechanical environment.

Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

A cyclic pressure bioreactor capable of subjecting heart valve tissue to physiological and pathological pressure conditions has been designed. A LabVIEW program allows users to control pressure magnitude, amplitude and frequency. This device can be used to study the mechanobiology of heart valve tissue or isolated cells.

עיצוב של bioreactor לחץ על מחזורי Ex Vivo מחקר של מסתמי הלב אבי העורקים

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic ...

Low Molecular Weight Protein Enrichment on Mesoporous Silica Thin Films for Biomarker Discovery

The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the monitoring of therapeutic efficiency.1-3 The circulating low molecular weight proteome (LMWP) composed of small proteins shed from tissues and cells or peptide fragments derived from the proteolytic degradation of larger proteins, has been associated with the pathological condition in patients and likely reflects the state of disease.4,5 Despite these potential clinical applications, the use of Mass Spectrometry (MS) to profile the LMWP from biological fluids has proven to be very challenging due to the large dynamic range of protein and peptide concentrations in serum.6 Without sample pre-treatment, some of the more highly abundant proteins obscure the detection of low-abundance species in serum/plasma. Current proteomic-based approaches, such as two-dimensional polyacrylamide gel-electrophoresis (2D-PAGE) and shotgun proteomics methods are labor-intensive, low throughput and offer limited suitability for clinical applications.7-9 Therefore, a more effective strategy is needed to isolate LMWP from blood and allow the high throughput screening of clinical samples. 
Here, we present a fast, efficient and reliable multi-fractionation system based on mesoporous silica chips to specifically target and enrich LMWP.10,11 Mesoporous silica (MPS) thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway. Using different polymer templates and polymer concentrations in the precursor solution, various pore size distributions, pore structures, connectivity and surface properties were determined and applied for selective recovery of low mass proteins. The selective parsing of the enriched peptides into different subclasses according to their physicochemical properties will enhance the efficiency of recovery and detection of low abundance species. In combination with mass spectrometry and statistic analysis, we demonstrated the correlation between the nanophase characteristics of the mesoporous silica thin films and the specificity and efficacy of low mass proteome harvesting. The results presented herein reveal the potential of the nanotechnology-based technology to provide a powerful alternative to conventional methods for LMWP harvesting from complex biological fluids. Because of the ability to tune the material properties, the capability for low-cost production, the simplicity and rapidity of sample collection, and the greatly reduced sample requirements for analysis, this novel nanotechnology will substantially impact the field of proteomic biomarker research and clinical proteomic assessment.

We developed a technology based on mesoporous silica thin film for the selective recovery of low molecular weight proteins and peptides from human serum. The physico-chemical properties of our mesoporous chips were finely tuned to provide substantial control in peptide enrichment and consequently profile the serum proteome for diagnostic purposes.

חלבון נמוך מולקולרית משקל העשרה על סרטים סיליקה mesoporous דק גילוי סמן ביולוגי

The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the ...

Insertion of Flexible Neural Probes Using Rigid Stiffeners Attached with Biodissolvable Adhesive

Microelectrode arrays for neural interface devices that are made of biocompatible thin-film polymer are expected to have extended functional lifetime because the flexible material may minimize adverse tissue response caused by micromotion. However, their flexibility prevents them from being accurately inserted into neural tissue. This article demonstrates a method to temporarily attach a flexible microelectrode probe to a rigid stiffener using biodissolvable polyethylene glycol (PEG) to facilitate precise, surgical insertion of the probe. A unique stiffener design allows for uniform distribution of the PEG adhesive along the length of the probe. Flip-chip bonding, a common tool used in microelectronics packaging, enables accurate and repeatable alignment and attachment of the probe to the stiffener. The probe and stiffener are surgically implanted together, then the PEG is allowed to dissolve so that the stiffener can be extracted leaving the probe in place. Finally, an in vitro test method is used to evaluate stiffener extraction in an agarose gel model of brain tissue. This approach to implantation has proven particularly advantageous for longer flexible probes (&gt;3 mm). It also provides a feasible method to implant dual-sided flexible probes. To date, the technique has been used to obtain various in vivo recording data from the rat cortex.

Insertion of flexible neural microelectrode probes is enabled by attaching probes to rigid stiffeners with polyethylene glycol (PEG). A unique assembly process ensures uniform and repeatable attachment. After insertion into tissue, the PEG dissolves and the stiffener is extracted. An in vitro test method evaluates the technique in agarose gel.

החדרת גמישה עצביות בדיקות באמצעות אלמנטים קשיחות קשיחים מצורפים עם Biodissolvable דבק

Microelectrode  arrays for neural interface devices that are made of biocompatible thin-film  polymer are expected to have extended functional lifetime ...

Optical Detection of E. coli Bacteria by Mesoporous Silicon Biosensors

A label-free optical biosensor based on a nanostructured porous Si is designed for rapid capture and detection of Escherichia coli K12 bacteria, as a model microorganism. The biosensor relies on direct binding of the target bacteria cells onto its surface, while no pretreatment (e.g.&#160;by cell lysis) of the studied sample is required. A mesoporous Si thin film is used as the optical transducer element of the biosensor. Under white light illumination, the porous layer displays well-resolved Fabry-P&#233;rot fringe patterns in its reflectivity spectrum. Applying a fast Fourier transform (FFT) to reflectivity data results in a single peak. Changes in the intensity of the FFT peak are monitored. Thus, target bacteria capture onto the biosensor surface, through antibody-antigen interactions, induces measurable changes in the intensity of the FFT peaks, allowing for a &#39;real time&#39; observation of bacteria attachment.
The mesoporous Si film, fabricated by an electrochemical anodization process, is conjugated with monoclonal antibodies, specific to the target bacteria. The immobilization, immunoactivity and specificity of the antibodies are confirmed by fluorescent labeling experiments. Once the biosensor is exposed to the target bacteria, the cells are directly captured onto the antibody-modified porous Si surface. These specific capturing events result in intensity changes in the thin-film optical interference spectrum of the biosensor. We demonstrate that these biosensors can detect relatively low bacteria concentrations (detection limit of 104 cells/ml) in less than an hour.

Optical Detection of E. coli Bacteria by Mesoporous Silicon Biosensors

A label-free optical biosensor for rapid bacteria detection is introduced. The biosensor is based on a nanostructured porous Si, which is designed to directly capture the target bacteria cells onto its surface. We use monoclonal antibodies, immobilized onto the porous transducer, as the capture probes. Our studies demonstrate the applicability of these biosensors for the detection of low bacterial concentrations within minutes with no prior sample processing (such as cell lysis).

זיהוי אופטי של<em&gt; א coli</em&gt; חיידקים על ידי Biosensors הסיליקון Mesoporous

A label-free optical biosensor based on a nanostructured porous Si is designed for rapid capture and detection of Escherichia coli K12 bacteria, as a ...

Wideband Optical Detector of Ultrasound for Medical Imaging Applications

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic imaging. In medical applications, one of the major limitations of optical sensing technology is its susceptibility to environmental conditions, e.g. changes in pressure and temperature, which may saturate the detection. Additionally, the clinical environment often imposes stringent limits on the size and robustness of the sensor. In this work, the combination of pulse interferometry and fiber-based optical sensing is demonstrated for ultrasound detection. Pulse interferometry enables robust performance of the readout system in the presence of rapid variations in the environmental conditions, whereas the use of all-fiber technology leads to a mechanically flexible sensing element compatible with highly demanding medical applications such as intravascular imaging. In order to achieve a short sensor length, a pi-phase-shifted fiber Bragg grating is used, which acts as a resonator trapping light over an effective length of 350 &#181;m. To enable high bandwidth, the sensor is used for sideway detection of ultrasound, which is highly beneficial in circumferential imaging geometries such as intravascular imaging. An optoacoustic imaging setup is used to determine the response of the sensor for acoustic point sources at different positions.

Optical detection of ultrasound is impractical in many imaging scenarios because it often requires stable environmental conditions. We demonstrate an optical technique for ultrasound sensing in volatile environments with miniaturization and sensitivity levels appropriate for optoacoustic imaging in restrictive scenarios, e.g. intravascular applications.

Wideband גלאי אופטיים של אולטראסאונד ליישומי הדמיה רפואית

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic ...

Use of Label-free Optical Biosensors to Detect Modulation of Potassium Channels by G-protein Coupled Receptors

Ion channels control the electrical properties of neurons and other excitable cell types by selectively allowing ions to flow through the plasma membrane1. To regulate neuronal excitability, the biophysical properties of ion channels are modified by signaling proteins and molecules, which often bind to the channels themselves to form a heteromeric channel complex2,3. Traditional assays examining the interaction between channels and regulatory proteins require exogenous labels that can potentially alter the protein&#39;s behavior and decrease the physiological relevance of the target, while providing little information on the time course of interactions in living cells. Optical biosensors, such as the X-BODY Biosciences BIND Scanner system, use a novel label-free technology, resonance wavelength grating (RWG) optical biosensors, to detect changes in resonant reflected light near the biosensor. This assay allows the detection of the relative change in mass within the bottom portion of living cells adherent to the biosensor surface resulting from ligand induced changes in cell adhesion and spreading, toxicity, proliferation, and changes in protein-protein interactions near the plasma membrane. RWG optical biosensors have been used to detect changes in mass near the plasma membrane of cells following activation of G protein-coupled receptors (GPCRs), receptor tyrosine kinases, and other cell surface receptors. Ligand-induced changes in ion channel-protein interactions can also be studied using this assay. In this paper, we will describe the experimental procedure used to detect the modulation of Slack-B sodium-activated potassium (KNa) channels by GPCRs.

Optical biosensor techniques can detect changes in mass near the plasma membrane in living cells and allow one to follow cellular responses in both individual cells and populations of cells. This protocol will describe detection of the modulation of potassium channels by G-protein coupled receptors in intact cells using this approach.

שימוש בBiosensors האופטי ללא תווית לזיהוי מודולציה של תעלות אשלגן על ידי קולטנים מצמידים G-חלבון

Ion channels control the electrical properties of neurons and other excitable cell types by selectively allowing ions to flow through the plasma ...

Preparation of Mica Supported Lipid Bilayers for High Resolution Optical Microscopy Imaging

Supported lipid bilayers (SLBs) are widely used as a model for studying membrane properties (phase separation, clustering, dynamics) and its interaction with other compounds, such as drugs or peptides. However SLB characteristics differ depending on the support used. 
Commonly used techniques for SLB imaging and measurements are single molecule fluorescence microscopy, FCS and atomic force microscopy (AFM). Because most optical imaging studies are carried out on a glass support, while AFM requires an extremely flat surface (generally mica), results from these techniques cannot be compared directly, since the charge and smoothness properties of these materials strongly influence diffusion. Unfortunately, the high level of manual dexterity required for the cutting and gluing thin slices of mica to the glass slide presents a hurdle to routine use of mica for SLB preparation. Although this would be the method of choice, such prepared mica surfaces often end up being uneven (wavy) and difficult to image, especially with small working distance, high numerical aperture lenses. Here we present a simple and reproducible method for preparing thin, flat mica surfaces for lipid vesicle deposition and SLB preparation. Additionally, our custom made chamber requires only very small volumes of vesicles for SLB formation. The overall procedure results in the efficient, simple and inexpensive production of high quality lipid bilayer surfaces that are directly comparable to those used in AFM studies.

We present a method of preparing mica supported lipid bilayers for high resolution microscopy. Mica is transparent and flat on an atomic scale, but rarely used in imaging because of handling difficulties; our preparation results in even deposition of the mica sheet, and reduces the material used in bilayer preparation.

הכנת מיכה נתמכת יפידים bilayers לרזולוציה גבוהה מיקרוסקופיה אופטית הדמיה

Supported lipid bilayers (SLBs) are widely used as a model for studying membrane properties (phase separation, clustering, dynamics) and its interaction ...

Label-free Single Molecule Detection Using Microtoroid Optical Resonators

Detecting small concentrations of molecules down to the single molecule limit has impact on areas such as early detection of disease, and fundamental studies on the behavior of molecules. Single molecule detection techniques commonly utilize labels such as fluorescent tags or quantum dots, however, labels are not always available, increase cost and complexity, and can perturb the events being studied. Optical resonators have emerged as a promising means to detect single molecules without the use of labels. Currently the smallest particle detected by a non-plasmonically-enhanced bare optical resonator system in solution is a 25 nm polystyrene sphere1. We have developed a technique known as Frequency Locking Optical Whispering Evanescent Resonator (FLOWER) that can surpass this limit and achieve label-free single molecule detection in aqueous solution2. As signal strength scales with particle volume, our work represents a &#62; 100x improvement in the signal to noise ratio (SNR) over the current state of the art. Here the procedures behind FLOWER are presented in an effort to increase its usage in the field.

We have developed a label-free biosensing system based on optical resonator technology known as Frequency Locking Optical Whispering Evanescent Resonator (FLOWER) that is capable of detecting single molecules in solution. Here the procedures behind this work are described and presented.

ללא תווית מולקולה בודדת איתור באמצעות תהודה אופטית Microtoroid

Detecting small concentrations of molecules down to the single molecule limit has impact on areas such as early detection of disease, and fundamental ...

Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts

A major parameter determining the success of a bone-grafting procedure is vascularization of the area surrounding the graft. We hypothesized that implantation of a bone autograft would induce greater bone regeneration by abundant blood vessel formation. To investigate the effect of the graft on neovascularization at the defect site, we developed a micro&#8211;computed tomography (&#181;CT) approach to characterize newly forming blood vessels, which involves systemic perfusion of the animal with a polymerizing contrast agent. This method enables detailed vascular analysis of an organ in its entirety. Additionally, blood perfusion was assessed using fluorescence imaging (FLI) of a blood-borne fluorescent agent. Bone formation was quantified by FLI using a hydroxyapatite-targeted probe and &#181;CT analysis. Stem cell recruitment was monitored by bioluminescence imaging (BLI) of transgenic mice that express luciferase under the control of the osteocalcin promoter. Here we describe and demonstrate preparation of the allograft, calvarial defect surgery, &#181;CT scanning protocols for the neovascularization study and bone formation analysis (including the in vivo perfusion of contrast agent), and the protocol for data analysis.
The 3D high-resolution analysis of vasculature demonstrated significantly greater angiogenesis in animals with implanted autografts, especially with respect to arteriole formation. Accordingly, blood perfusion was significantly higher in the autograft group by the 7th day after surgery. We observed superior bone mineralization and measured greater bone formation in animals that received autografts. Autograft implantation induced resident stem cell recruitment to the graft-host bone suture, where the cells differentiated into bone-forming cells between the 7th and 10th postoperative day. This finding means that enhanced bone formation may be attributed to the augmented vascular feeding that characterizes autograft implantation. The methods depicted may serve as an optimal tool to study bone regeneration in terms of tightly bounded bone formation and neovascularization.

Implantation of autologous and allogeneic bone grafts constitute accepted approaches to treat major craniofacial bone loss. Yet the effect of graft composition on the interplay among neovascularization, cell differentiation and bone formation is unclear. We present a multimodal imaging protocol aimed to elucidate the angiogenesis-osteogenesis interdependence at the graft proximity.