وقد تم تمويل هذا العمل عن طريق التوظيف NSF CBET - 0747615. فإن الكتاب أود أن أشكر الدكاترة. دوجلاس سميث وديفيد لMeaney F. الإرشاد والدعم.

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Y., Gordon, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cellular+and+molecular+basis+of+peripheral+nerve+regeneration.">The cellular and molecular basis of peripheral nerve regeneration.</a> Mol Neurobiol. 14, 1-2 (1997).</li><li>Gray, C., Hukkanen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+neural+growth:+calcitonin+gene-related+peptide+and+substance+P-+containing+nerves+attain+exceptional+growth+rates+in+regenerating+deer+antler.">Rapid neural growth: calcitonin gene-related peptide and substance P- containing nerves attain exceptional growth rates in regenerating deer antler.</a> Neuroscience. 50, 953-963 (1992).</li><li>Heidemann, S. R., Buxbaum, R. 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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+survival+and+outgrowth+of+mechanically+engineered+nervous+tissue+constructs+implanted+into+spinal+cord+lesions.">Long-term survival and outgrowth of mechanically engineered nervous tissue constructs implanted into spinal cord lesions.</a> Tissue Eng. 12, 101-110 (2006).</li><li>Lamoureux, P., Heidemann, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+elongation+within+and+along+the+axon.">Growth and elongation within and along the axon.</a> Dev Neurobiol. 70, 135-149 (2010).</li><li>Lamoureux, P., Zheng, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+cytomechanical+investigation+of+neurite+growth+on+different+culture+surfaces.">A cytomechanical investigation of neurite growth on different culture surfaces.</a> J Cell Biol. 118, 655-661 (1992).</li><li>Lindqvist, N., Liu, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+glial+(Muller)+cells:+sensing+and+responding+to+tissue+stretch.">Retinal glial (Muller) cells: sensing and responding to tissue stretch.</a> Invest Ophthalmol Vis Sci. 51, 1683-1690 (2010).</li><li>Loverde, J. R., Ozoka, V. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+Imaging+of+Axon+Stretch+Growth+in+Embryonic+and+Adult+Neurons.">Live Imaging of Axon Stretch Growth in Embryonic and Adult Neurons.</a> J. Neurotrauma. , (2011).</li><li>Lu, Y. B., Franze, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Viscoelastic+properties+of+individual+glial+cells+and+neurons+in+the+CNS.">Viscoelastic properties of individual glial cells and neurons in the CNS.</a> Proc Natl Acad Sci U S A. 103, 17759-17764 (2006).</li><li>O'Toole, M., Lamoureux, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+physical+model+of+axonal+elongation:+force,+viscosity,+and+adhesions+govern+the+mode+of+outgrowth.">A physical model of axonal elongation: force, viscosity, and adhesions govern the mode of outgrowth.</a> Biophys J. 94, 2610-2620 (2008).</li><li>Pfister, B. J., Bonislawski, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stretch-grown+axons+retain+the+ability+to+transmit+active+electrical+signals.">Stretch-grown axons retain the ability to transmit active electrical signals.</a> FEBS Lett. 580, 3525-3531 (2006).</li><li>Pfister, B. J., Gordon, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomedical+Engineering+Strategies+for+Peripheral+Nerve+Repair:+Surgical+Applications,+State+of+the+Art,+and+Future+Challenges.">Biomedical Engineering Strategies for Peripheral Nerve Repair: Surgical Applications, State of the Art, and Future Challenges.</a> Crit Rev Biomed Eng. 39, 81-124 (2011).</li><li>Pfister, B. J., Iwata, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extreme+stretch+growth+of+integrated+axons.">Extreme stretch growth of integrated axons.</a> J Neurosci. 24, 7978-7983 (2004).</li><li>Pfister, B. J., Iwata, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+transplantable+nervous+tissue+constructs+comprised+of+stretch-grown+axons.">Development of transplantable nervous tissue constructs comprised of stretch-grown axons.</a> J Neurosci Methods. 153, 95-103 (2006).</li><li>Siechen, S., Yang, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+tension+contributes+to+clustering+of+neurotransmitter+vesicles+at+presynaptic+terminals.">Mechanical tension contributes to clustering of neurotransmitter vesicles at presynaptic terminals.</a> Proc Natl Acad Sci U S A. 106, 12611-12616 (2009).</li><li>Smith, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stretch+growth+of+integrated+axon+tracts:+extremes+and+exploitations.">Stretch growth of integrated axon tracts: extremes and exploitations.</a> Prog Neurobiol. 89, 231-239 (2009).</li><li>Smith, D. H., Wolf, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+strategy+to+produce+sustained+growth+of+central+nervous+system+axons:+continuous+mechanical+tension.">A new strategy to produce sustained growth of central nervous system axons: continuous mechanical tension.</a> Tissue Eng. 7, 131-139 (2001).</li><li>Weiss, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nerve+patterns:+The+mechanics+of+nerve+growth.">Nerve patterns: The mechanics of nerve growth.</a> Growth, Third Growth Symposium. 5, 163-203 (1941).</li><li>Zheng, J., Lamoureux, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tensile+regulation+of+axonal+elongation+and+initiation.">Tensile regulation of axonal elongation and initiation.</a> J Neurosci. 11, 1117-1125 (1991).</li></ol>

هي براءة اختراع للاستطالة السابقين فيفو الميكانيكية للخلايا العصبية بموجب براءات الاختراع الأميركية # # 7429267 6264944 و.

ينبغي التقيد خطوتين حرجة خلال إعداد المفاعلات الحيوية. أولا ، هناك حاجة إلى وجود تداخل في واجهة مثالية لضمان الركيزة محاور عصبية يمكن أن يعبر على الركيزة الثابتة. وينبغي أن Aclar كرة لولبية بشكل مفرط أو غير ذلك الكمال لا يمكن استخدامها (الشكل 3). لتحسين التداخل ، تأكيد أن يتم غطى بالرمل الركيزة القطر بالتساوي والاتصالات الركيزة الثابتة بشكل موحد على مدى التصحيح 2 - 3mm الاتصال طويلة. وينبغي أن يكون الأمثل للتداخل قبل كل تجربة من خلال تعديل بعناية ارتفاع الساقين القطر. الثانية ، في حين ينص على مرفق من الخلايا العصبية ، والطلاء الركيزة دعم قوات كبيرة sheering الناجمة عن النزوح من التوتر مفاعل حيوي ومقلص من المحاور (هايدمان وBuxbaum 1990 ؛ فيستر ايواتا وآخرون 2004 ؛. Loverde ، Ozoka وآخرون 2011). وينبغي أن تشطف جيدا بالماء ركائز تعقيمها قبل وبعد طلاء يسين. ينبغي أن تطبق الطلاء من aliquots إذابة طازجة وموزعة بالتساوي قدر الإمكان. الأهم من ذلك ، ينبغي على ركائز لا يمكن نقله أو خلاف ذلك اضطراب خلال الفترة من الالتصاق. في خطوات لاحقة ، وتجنب الاتصال مع ركائز خلال الطلاء ، وجميع الحلول الماصة من نهاية بكثير من الممرات بعيدا عن واجهة الركيزة. يمكن التحمل في الاتصالات من كل مكون مفاعل حيوي واضح في شكل الركود. خلال الفترة الأولى من جماعة أبو سياف ، الترهل في النظام كما يتضح من الجدول الحركة الحركة الخطية الآلي يحدث دون وجود تحرك للكتلة السحب. يمكن أن تختلف والترهل في التجربة ، بل هو عادة &lt;1MM في تجربتنا. لهذا السبب ، وهو &quot;ما قبل التوتر&quot; مرحلة التخلص من الترهل 1mm/day ، ليوم واحد يسبق الجدول الزمني للجماعة أبو سياف خلالها أجزاء مفاعل حيوي والبدء في إشراك حركة ركائز القطر. قد تكون مطلوبة لحل المشاكل إذا كانت الخطوة تشريد الجدول الحركة الخطية الآلي لا يطابق تشريد كتلة السحب بعد مرحلة ما قبل اكتمال التوتر. وترتبط متزامنة ، وتشريد غير دقيقة للكتلة السحب مع &#39;stiction&#39; أو الاحتكاك ثابت داخل أجهزة السحب والثناء من المحول. لمنع حدوث هذه القضايا ، ينبغي التحقق من كتلة حركة السحب من جهة ، وبعد التجميع ، على حركة شبه سهل سلس. إذا ملزم يحدث ، ينبغي الافراج عن التجمع القطر قبل التجريب. صلابة كافية لمحول من الضروري أيضا ضمان دقة ، وتشريد متزامن لم يتم التغلب بواسطة stiction للأجهزة السحب.

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> اسم العنصر </td><td> شركة </td><td> فهرس العدد </td><td> تعليقات </td></tr><tr><td> PolyEtherEtherKetone (نظرة خاطفة) </td><td> ماكماستر ، كار ، إلمهورست ، IL </td><td> 8504K69 </td><td> قدمت غرفة مخصصة مفاعل حيوي </td></tr><tr><td> البولي </td><td> ماكماستر ، كار ، إلمهورست ، IL </td><td> 8574K28 </td><td> قدمت غطاء غرفة مخصصة مفاعل حيوي </td></tr><tr><td> السائر المحركات </td><td> منتجات موشن التطبيقية ، اتسونفيل ، كاليفورنيا </td><td> HT23 - 397 </td><td></td></tr><tr><td> الحركة الخطية الجدول </td><td> أنظمة هيدروليك ، مونتفيل ، NJ </td><td> MIPS - 2 - 10 - 1.0mm </td><td></td></tr><tr><td> الخطوة تحكم محرك السيارات </td><td> منتجات موشن التطبيقية ، اتسونفيل ، كاليفورنيا </td><td> Si2035 </td><td></td></tr><tr><td> Aclar </td><td> دقق هيكل ، وشركة غرب تشيستر ، والسلطة الفلسطينية </td><td> 1859 </td><td> تقطر ركائز الثقافة </td></tr><tr><td> ساترة رقم (1) </td><td> الدماغ المعامل البحثية ، نيوتن ، MA </td><td> 4865-1 </td><td> الركيزة الثابتة ثقافة </td></tr><tr><td> السيليكون RTV </td><td> ماكماستر ، كار ، إلمهورست ، IL </td><td> 7587A37 </td><td></td></tr><tr><td> مسحات القطن ذات الرؤوس </td><td> ماكماستر ، كار ، إلمهورست ، IL </td><td> 7074T62 </td><td></td></tr><tr><td> بولي - D - يسين </td><td> دينار بحريني ، بيدفورد ، ماجستير </td><td> 354210 </td><td></td></tr></tbody></table>

axon stretch growth: the mechanotransduction of neuronal growth

خلال مرحلة ما قبل متشابك التطور الجنيني ، والعمليات العصبية اجتياز مسافات قصيرة للوصول إلى أهدافها عن طريق مخروط النمو. بمرور الوقت ، يتم فصل الخلايا العصبية من محطات somata محوار ، نظرا لنمو الهيكل العظمي للكائن توسيع (فايس 1941 ؛ رمادي ، Hukkanen وآخرون 1992). هذا يؤدي الى وضع mechanotransduction الثانوية للنمو الخلايا العصبية قادرة على استيعاب استطالة المستمر للمحوار (براي 1984 ؛ هايدمان وBuxbaum 1994 ؛ هايدمان ، لامورو وآخرون 1995 ؛. فيستر ايواتا وآخرون 2004). محوار النمو الإمتداد (ASG) هو تصور عاملا أساسيا في نضج العمليات الجنينية قصيرة في الأعصاب طويلة ومساحات المادة البيضاء من سمات النظام العصبي البالغين. الأمين العام المساعد للدراسة في المختبر ، ونحن تصميم المفاعلات الحيوية لتطبيق التوتر على العمليات محواري قصيرة من الثقافات العصبية (Loverde ، Ozoka وآخرون 2011). هنا ، ونحن بالتفصيل الأساليب التي نستخدمها لإعداد المفاعلات الحيوية والسلوك أمين عام مساعد. أولا ، في كل حارة تمتد من مفاعل حيوي ، ومطلي الخلايا العصبية عند الركيزة a القطر الصغير التلاعب بها. المقبل ، تجديد الخلايا العصبية محواري عملياتها ، عبر تمديد مخروط النمو ، وعلى ركيزة ثابتة. أخيرا ، يتم تنفيذ النمو التي تمتد سحب جثث مطلي الخلية بعيدا عن محطات محوار انضمت إلى الركيزة الثابتة ؛ تلخص نمو الهيكل العظمي بعد التمديد مخروط النمو. وقد أظهرت الأعمال السابقة أن جماعة أبو سياف من الفئران الجنينية الخلايا العصبية الظهرية العقد الجذرية القادرة على معدلات نمو غير مسبوقة تصل إلى 10mm/day ، حيث بلغت أطوال تصل إلى 10cm ، في حين أدى في الوقت نفسه زيادة في أقطار محواري (سميث وولف وآخرون 2001 ؛. فيستر ايواتا وآخرون 2004 ؛. فيستر Bonislawski وآخرون 2006 ؛. فيستر ايواتا وآخرون 2006 ؛ سميث 2009). هذا في تناقض مثير للتمديد مخروط النمو التجديدي (في غياب المحفزات الميكانيكية) حيث متوسط ​​معدلات النمو 1mm/day مع التجديد الناجحة تقتصر على أطوال أقل من 3cm (فو وغوردون 1997 ؛. فيستر ، غوردون وآخرون 2011). وبالتالي يجوز إجراء مزيد من الدراسة لكشف الأمين العام المساعد مساعدة الآليات التي تحد من نمو dysregulated التجدد في ظل غياب المحفزات الميكانيكية.

Watch this Scientific Journal Video about Axon Stretch Growth: The Mechanotransduction of Neuronal Growth at JoVE.com

Axon Stretch Growth: The Mechanotransduction of Neuronal Growth

ووضعت هندسة الأنسجة طريقة فريدة لإطالة العديد من الألياف العصبية في الثقافة التي تلخص محوار نمو تمتد ؛ نموذج للنمو الجهاز العصبي حيث الأعصاب استطال بالتزامن مع نمو الجسم توسيع.

محوار النمو الإمتداد : إن Mechanotransduction من نمو الخلايا العصبية

During pre-synaptic embryonic development, neuronal processes traverse short distances to reach their targets via growth cone. Over time, neuronal somata ...

axon-stretch-growth-the-mechanotransduction-of-neuronal-growth

Research

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Bioengineering

16.7K Views.  New Jersey Institute of Technology. ووضعت هندسة الأنسجة طريقة فريدة لإطالة العديد من الألياف العصبية في الثقافة التي تلخص محوار نمو تمتد ؛ نموذج للنمو الجهاز العصبي حيث الأعصاب استطال بالتزامن مع نمو الجسم توسيع.

Video: Axon Stretch Growth: The Mechanotransduction of Neuronal Growth

Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest in using nano-colloids for photo-thermal ablation, drug delivery and many other biomedical applications 6. Gold is particularly used because of its low toxicity 7-9. A property of metal nano-colloids is that they can have a strong surface plasmon resonance 10. The peak of the surface plasmon resonance mode depends on the structure and composition of the metal nano-colloids. Since the surface plasmon resonance mode is stimulated with light there is a need to have the peak absorbance in the near infrared where biological tissue transmissivity is maximal 11, 12.
We present a method to synthesize star shaped colloidal gold, also known as star shaped nanoparticles 13-15 or nanostars 16. This method is based on a solution containing silver seeds that are used as the nucleating agent for anisotropic growth of gold colloids 17-22. Scanning electron microscopy (SEM) analysis of the resulting gold colloid showed that 70 % of the nanostructures were nanostars. The other 30 % of the particles were amorphous clusters of decahedra and rhomboids. The absorbance peak of the nanostars was detected to be in the near infrared (840 nm). Thus, our method produces gold nanostars suitable for biomedical applications, particularly for photo-thermal ablation.

We synthesized star shaped gold nanostars using a silver seed mediated growth method. The diameter of the nanostars ranges from 200 to 300 nm and the number of tips vary from 7 to 10. The nanoparticles have a broad surface plasmon resonance mode centered in the near infrared.

الذهب Nanostar التجميعي مع أسلوب بذور فضة النمو وساطة

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest ...

Magnetic Resonance Elastography Methodology for the Evaluation of Tissue Engineered Construct Growth

Traditional mechanical testing often results in the destruction of the sample, and in the case of long term tissue engineered construct studies, the use of destructive assessment is not acceptable. A proposed alternative is the use of an imaging process called magnetic resonance elastography. Elastography is a nondestructive method for determining the engineered outcome by measuring local mechanical property values (i.e., complex shear modulus), which are essential markers for identifying the structure and functionality of a tissue. As a noninvasive means for evaluation, the monitoring of engineered constructs with imaging modalities such as magnetic resonance imaging (MRI) has seen increasing interest in the past decade1. For example, the magnetic resonance (MR) techniques of diffusion and relaxometry have been able to characterize the changes in chemical and physical properties during engineered tissue development2. The method proposed in the following protocol uses microscopic magnetic resonance elastography (&mu;MRE) as a noninvasive MR based technique for measuring the mechanical properties of small soft tissues3. MRE is achieved by coupling a sonic mechanical actuator with the tissue of interest and recording the shear wave propagation with an MR scanner4. Recently, &mu;MRE has been applied in tissue engineering to acquire essential growth information that is traditionally measured using destructive mechanical macroscopic techniques5. In the following procedure, elastography is achieved through the imaging of engineered constructs with a modified Hahn spin-echo sequence coupled with a mechanical actuator. As shown in Figure 1, the modified sequence synchronizes image acquisition with the transmission of external shear waves; subsequently, the motion is sensitized through the use of oscillating bipolar pairs. Following collection of images with positive and negative motion sensitization, complex division of the data produce a shear wave image. Then, the image is assessed using an inversion algorithm to generate a shear stiffness map6. The resulting measurements at each voxel have been shown to strongly correlate (R2&gt;0.9914) with data collected using dynamic mechanical analysis7. In this study, elastography is integrated into the tissue development process for monitoring human mesenchymal stem cell (hMSC) differentiation into adipogenic and osteogenic constructs as shown in Figure 2.

The procedure demonstrates the methodology of magnetic resonance elastography for monitoring the engineered outcome of adipose and osteogenic tissue engineered constructs through noninvasive local assessment of the mechanical properties using microscopic magnetic resonance elastography (&mu;MRE).

المغناطيسي منهجية Elastography الرنين لتقييم الأنسجة المهندسة النمو كونستركت

Traditional mechanical testing often results in the destruction of the sample, and in the case of long term tissue engineered construct studies, the use ...

Time-lapse Fluorescence Imaging of Arabidopsis Root Growth with Rapid Manipulation of The Root Environment Using The RootChip

The root functions as the physical anchor of the plant and is the organ responsible for uptake of water and mineral nutrients such as nitrogen, phosphorus, sulfate and trace elements that plants acquire from the soil. If we want to develop sustainable approaches to producing high crop yield, we need to better understand how the root develops, takes up a wide spectrum of nutrients, and interacts with symbiotic and pathogenic organisms. To accomplish these goals, we need to be able to explore roots in microscopic detail over time periods ranging from minutes to days.
We developed the RootChip, a polydimethylsiloxane (PDMS)- based microfluidic device, which allows us to grow and image roots from Arabidopsis seedlings while avoiding any physical stress to roots during preparation for imaging1 (Figure 1). The device contains a bifurcated channel structure featuring micromechanical valves to guide the fluid flow from solution inlets to each of the eight observation chambers2. This perfusion system allows the root microenvironment to be controlled and modified with precision and speed. The volume of the chambers is approximately 400 nl, thus requiring only minimal amounts of test solution.
Here we provide a detailed protocol for studying root biology on the RootChip using imaging-based approaches with real time resolution. Roots can be analyzed over several days using time lapse microscopy. Roots can be perfused with nutrient solutions or inhibitors, and up to eight seedlings can be analyzed in parallel. This system has the potential for a wide range of applications, including analysis of root growth in the presence or absence of chemicals, fluorescence-based analysis of gene expression, and the analysis of biosensors, e.g. FRET nanosensors3.

This article provides a protocol for cultivation of Arabidopsis seedlings in the RootChip, a microfluidic imaging platform that combines automated control of growth conditions with microscopic root monitoring and FRET-based measurement of intracellular metabolite levels.

الوقت الفاصل بين التصوير الإسفار من نمو الجذور Arabidopsis مع التلاعب السريع للبيئة الجذر باستخدام RootChip

The root functions as the physical anchor of the plant and is the organ responsible for uptake of water and mineral nutrients such as nitrogen, ...

Electrospinning Growth Factor Releasing Microspheres into Fibrous Scaffolds

This procedure describes a method to fabricate a multifaceted substrate to direct nerve cell growth. This system incorporates mechanical, topographical, adhesive and chemical signals. Mechanical properties are controlled by the type of material used to fabricate the electrospun fibers. In this protocol we use 30% methacrylated Hyaluronic Acid (HA), which has a tensile modulus of ~500 Pa, to produce a soft fibrous scaffold. Electrospinning on to a rotating mandrel produces aligned fibers to create a topographical cue. Adhesion is achieved by coating the scaffold with fibronectin. The primary challenge addressed herein is providing a chemical signal throughout the depth of the scaffold for extended periods. This procedure describes fabricating&#160;poly(lactic-co-glycolic acid) (PLGA) microspheres that contain Nerve Growth Factor (NGF) and directly impregnating the scaffold with these microspheres during the electrospinning process. Due to the harsh production environment, including high sheer forces and electrical charges, protein viability is measured after production. The system provides protein release for over 60 days and has been shown to promote primary nerve cell growth.

This protocol combines electrospinning and microspheres to develop tissue engineered scaffolds to direct neurons. Nerve growth factor was encapsulated within PLGA microspheres and electrospun into Hyaluronic Acid (HA) fibrous scaffolds. The protein bioactivity was tested by seeding the scaffolds with primary chick Dorsal Root Ganglia and culturing for 4-6 days.

عامل نمو Electrospinning الافراج الجزئي في الليفية السقالات

This procedure describes a method to fabricate a multifaceted substrate to direct nerve cell growth.  This system incorporates mechanical, topographical, ...

Studying the Stoichiometry of Epidermal Growth Factor Receptor in Intact Cells using Correlative Microscopy

This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative fluorescence microscopy and environmental scanning electron microscopy (ESEM) of whole cells in hydrated state. Fluorescent quantum dots (QDs) were coupled to EGFR via a two-step labeling protocol, providing an efficient and specific protein labeling, while avoiding label-induced clustering of the receptor. Fluorescence microscopy provided overview images of the cellular locations of the EGFR. The scanning transmission electron microscopy (STEM) detector was used to detect the QD labels with nanoscale resolution. The resulting correlative images provide data of the cellular EGFR distribution, and the stoichiometry at the single molecular level in the natural context of the hydrated intact cell. ESEM-STEM images revealed the receptor to be present as monomer, as homodimer, and in small clusters. Labeling with two different QDs, i.e.,&#160;one emitting at 655 nm and at 800 revealed similar characteristic results.

This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative light- and electron microscopy of whole cells in hydrated state. The label contained fluorescent quantum dots. The protocol can be used to study the stoichiometry of EGFR at the single molecule level.

دراسة رياضيات الكيمياء من البشرة عامل نمو مستقبلات في الخلايا السليمة باستخدام الميكروسكوب المتلازم

This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative fluorescence ...

Polyelectrolyte Complex for Heparin Binding Domain Osteogenic Growth Factor Delivery

During reconstructive bone surgeries, supraphysiological amounts of growth factors are empirically loaded onto scaffolds to promote successful bone fusion. Large doses of highly potent biological agents are required due to growth factor instability as a result of rapid enzymatic degradation as well as carrier inefficiencies in localizing sufficient amounts of growth factor at implant sites. Hence, strategies that prolong the stability of growth factors such as BMP-2/NELL-1, and control their release could actually lower their efficacious dose and thus reduce the need for larger doses during future bone regeneration surgeries. This in turn will reduce side effects and growth factor costs. Self-assembled PECs have been fabricated to provide better control of BMP-2/NELL-1 delivery via heparin binding and further potentiate growth factor bioactivity by enhancing in vivo stability. Here we illustrate the simplicity of PEC fabrication which aids in the delivery of a variety of growth factors during reconstructive bone surgeries.

Self-assembled polyelectrolyte complexes (PEC) fabricated from heparin and protamine were deposited on alginate beads to entrap and regulate the release of osteogenic growth factors. This delivery strategy enables a 20-fold reduction of BMP-2 dose in spinal fusion applications. This article illustrates the benefits and fabrication of PECs.

مجمع متضاعف الكتروليتي للهيبارين ربط تسليم عظمية عامل نمو المجال

During reconstructive bone surgeries, supraphysiological amounts of growth factors are empirically loaded onto scaffolds to promote successful bone ...

Designing Porous Silicon Films as Carriers of Nerve Growth Factor

Despite the great potential of NGF for treating neurodegenerative diseases, its therapeutic administration represents a significant challenge as the protein does not cross the blood-brain barrier, owing to its chemical properties, and thus requires long-term delivery to the brain to have a biological effect. This work describes fabrication of nanostructured PSi films as degradable carriers of NGF for sustained delivery of this sensitive protein. The PSi carriers are specifically tailored to obtain high loading efficacy and continuous release of NGF for a period of four weeks, while preserving its biological activity. The behavior of the NGF-PSi carriers as a NGF delivery system is investigated in vitro by examining their capability to induce neuronal differentiation and outgrowth of PC12 cells and dissociated DRG neurons. Cell viability in the presence of neat and NGF-loaded PSi carriers is evaluated. The bioactivity of NGF released from the PSi carriers is compared to the conventional treatment of repetitive free NGF administrations. PC12 cell differentiation is analyzed and characterized by the measurement of three different morphological parameters of differentiated cells; (i) the number of neurites extracting from the soma (ii) the total neurites' length and (iii) the number of branching points. PC12 cells treated with the NGF-PSi carriers demonstrate a profound differentiation throughout the release period. Furthermore, DRG neuronal cells cultured with the NGF-PSi carriers show an extensive neurite initiation, similar to neurons treated with repetitive free NGF administrations. The studied tunable carriers demonstrate the long-term implants for NGF release with a therapeutic potential for neurodegenerative diseases.

Here, we present a protocol to design and fabricate nanostructured porous silicon (PSi) films as degradable carriers for the nerve growth factor (NGF). Neuronal differentiation and outgrowth of PC12 cells and mice dorsal root ganglion (DRG) neurons are characterized upon treatment with the NGF-loaded PSi carriers.

تصميم أفلام السيليكون مسامية كحاملة لعامل نمو العصب

Despite the great potential of NGF for treating neurodegenerative diseases, its therapeutic administration represents a significant challenge as the ...

Growth and Characterization of Irradiated Organoids from Mammary Glands

Organoids derived from the digested tissue are multicellular three-dimensional (3D) constructs that better recapitulate in vivo conditions than cell monolayers. Although they cannot completely model in vivo complexity, they retain some functionality of the original organ. In cancer models, organoids are commonly used to study tumor cell invasion. This protocol aims to develop and characterize organoids from the normal and irradiated mouse mammary gland tissue to evaluate the radiation response in normal tissues. These organoids can be applied to future in vitro cancer studies to evaluate tumor cell interactions with irradiated organoids. Mammary glands were resected, irradiated to 20 Gy and digested in a collagenase VIII solution. Epithelial organoids were separated via centrifugal differentiation, and 3D organoids were developed in 96-well low-adhesion microplates. Organoids expressed the characteristic epithelial marker cytokeratin 14. Macrophage interaction with the organoids was observed in co-culture experiments. This model may be useful for studying tumor-stromal interactions, infiltration of immune cells, and macrophage polarization within an irradiated microenvironment.

Organoids developed from mouse mammary glands were irradiated and characterized to assess epithelial traits and interactions with immune cells. Irradiated organoids can be used to better evaluate cell-cell interactions that may lead to tumor cell recruitment in irradiated normal tissue.

نمو وتوصيف العضوية المشعة من الغدد الثديية

Organoids derived from the digested tissue are multicellular three-dimensional (3D) constructs that better recapitulate in vivo conditions than cell ...

A Simple Microfluidic Chip for Long-Term Growth and Imaging of Caenorhabditis elegans

Caenorhabditis elegans (C. elegans) have proved to be a valuable model system for studying developmental and cell biological processes. Understanding these biological processes often requires long-term and repeated imaging of the same animal. Long recovery times associated with conventional immobilization methods done on agar pads have detrimental effects on animal health making it inappropriate to repeatedly image the same animal over long periods of time. This paper describes a microfluidic chip design, fabrication method, on-chip C. elegans culturing protocol, and three examples of long-term imaging to study developmental processes in individual animals. The chip, fabricated with polydimethylsiloxane and bonded on a cover glass, immobilizes animals on a glass substrate using an elastomeric membrane that is deflected using nitrogen gas. Complete immobilization of C. elegans enables robust time-lapse imaging of cellular and sub-cellular events in an anesthetic-free manner. A channel geometry with a large cross-section allows the animal to move freely within two partially sealed isolation membranes permitting growth in the channel with a continuous food supply. Using this simple chip, imaging of developmental phenomena such as neuronal process growth, vulval development, and dendritic arborization in the PVD sensory neurons, as the animal grows inside the channel, can be performed. The long-term growth and imaging chip operates with a single pressure line, no external valves, inexpensive fluidic consumables, and utilizes standard worm handling protocols that can easily be adapted by other laboratories using C. elegans.

A Simple Microfluidic Chip for Long-Term Growth and Imaging of Caenorhabditis elegans

The protocol describes a simple microfluidic chip design and microfabrication methodology used to grow C. elegans in presence of a continuous food supply for up to 36 h. The growth and imaging device also enables intermittent long-term high-resolution imaging of cellular and sub-cellular processes during development for several days.

شريحة موائع دقيقة بسيطة للنمو على المدى الطويل وتصوير Caenorhabditis elegans

Caenorhabditis elegans (C. elegans) have proved to be a valuable model system for studying developmental and cell biological processes. Understanding ...

نظام جهاز صغير مشترك لتعزيز ومراقبة نمو الشعاب المرجانية

An Integrated Micro-Device System for Coral Growth and Monitoring

Corals are fundamental organisms in marine and coastal ecosystems. With the advancement of coral protection research in recent years, precise control of the coral culture environment is highly in demand for coral conservation and study. Here, we developed a semi-closed coral culture micro-device system as a multi-functional platform, which can provide accurate and programmable temperature control, a sterile initial environment, long-term stable water quality, an adjustable dissolved oxygen concentration, and a customized light spectrum for corals. Owing to the modular design, the coral culture system can be upgraded or modified by installing desirable new modules or removing existing ones. Currently, under appropriate conditions and with proper system maintenance, the sample corals can survive for at least 30 days in a healthy state. Furthermore, due to the controllable and sterile initial environment, this coral culture system can support research into the symbiotic relationship between corals and associated microorganisms. Therefore, this micro-device system can be applied to monitor and investigate sea corals in a relatively quantitative manner.

تسليط الضوء على المؤلف: النهوض بثقافة المرجان - إنشاء نظام بيئة دقيقة يتم التحكم فيه بشكل شبه كمي لمواجهة القيود الحالية 

This protocol describes the development of a modular controllable micro-device system that can be applied for the long-term culturing and monitoring of sea corals.

نظام جهاز دقيق متكامل لنمو المرجان ومراقبته

Corals are fundamental organisms in marine and coastal ecosystems. With the advancement of coral protection research in recent years, precise control of ...