https://engineering.wustl.edu/news/Pages/Nucleation-a-boon-to-sustainable-nanomanufacturing.aspx931Nucleation a boon to sustainable nanomanufacturing<img alt="" src="/news/PublishingImages/Jun%20-%20Nucleation.jpg" style="BORDER:0px solid;" /><div id="__publishingReusableFragmentIdSection"><a href="/ReusableContent/36_.000">a</a></div><p>Calcium carbonate is found nearly everywhere, in sidewalk cement, wall paint, antacid tablets <g class="gr_ gr_39 gr-alert gr_gramm gr_inline_cards gr_run_anim Punctuation only-ins replaceWithoutSep" id="39" data-gr-id="39">and</g> deep underground. Engineers at Washington University in St. Louis have used a unique set of state-of-the-art imaging techniques to discover how calcium carbonate nanoparticles nucleate, which is important for those manufacturing the carbonate nanomaterials and controlling metal carbonation during CO<sub>2</sub> sequestration.</p><p>Young-Shin Jun, professor of energy, environmental & chemical engineering in the School of Engineering & Applied Science, and <g class="gr_ gr_35 gr-alert gr_spell gr_inline_cards gr_run_anim ContextualSpelling ins-del multiReplace" id="35" data-gr-id="35">Quingun</g> Li, a former doctoral student in her lab, are the first to measure the activation energy and kinetic factors of calcium carbonate's nucleation, both key to predicting and controlling the process. Nucleation is the initial step in forming a solid phase in a fluid system, such as sugar crystals forming on <g class="gr_ gr_45 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar only-ins doubleReplace replaceWithoutSep" id="45" data-gr-id="45">string</g> to make rock candy. Results of the research are published in <em>Communications Chemistry</em> Sept. 19.</p><p> Jun, an expert in the nucleation of solids, and her team explored ways to govern the speed and location of nucleation, as well as the shape of the emerging solids.</p><p>"Our sensitivity test shows which synthesis conditions accelerate nucleation more effectively," she said.</p><blockquote>"Should we change the driving force by increasing the concentration of certain ion, or should we change the surface properties of the material or the system's temperature? Now we can predict this outcome."<br/></blockquote><p>Previously, when scientists described nucleation, they described the number of events occurring in a cubic or square meter every minute or every hour, but that did not give a full picture of the chemistry, Jun explained. With the new information, Jun and her team can say definitively how concentrated the calcium carbonate nanoparticles are in a given space over a given time period, which allows them to control nucleation. Until now, these thermodynamic and kinetic factors have remained unknown because real-time observations are difficult to perform on particles so small: The very first size of the calcium carbonate particles forming on quartz are about 8 nanometers, or 8 billionths of a meter, in diameter. Previous research in this area has been performed mainly with molecular modeling, which has been inadequate to reveal the kinetic factors of nucleation.  <br/></p><p>In experiments at Argonne National Laboratory, Jun's group used small angle X-ray scattering for <em>in situ</em> probing of the nanoparticles. In her lab at Washington University, they used atomic force microscopy for <em>ex situ</em> imaging of calcium carbonate nucleating on quartz.</p><p>"Knowing about nucleation empowers us to create nanomaterials and allows us to control nanoparticle properties and surface functionalization of materials, helping sustainable nanomanufacturing," Jun said. "Deciphering nucleation also aids in designing larger-scale engineering processes where nucleation changes the macroscopic properties of materials. Every single material starts with nucleation, so this process can be <g class="gr_ gr_42 gr-alert gr_spell gr_inline_cards gr_run_anim ContextualSpelling" id="42" data-gr-id="42">applicable</g> to anything. We now understand the 'start' better."<br/></p><SPAN ID="__publishingReusableFragment"></SPAN><p>Li Q and Jun Y-S. "The Apparent Activation Energy and Pre-Exponential Kinetic Factor for Heterogeneous Calcium Carbonate Nucleation on Quartz." <em>Communications Chemistry</em>, Sept. 19, 2018. DOI: 10.1038/s42004-018-0056-5. <a href="http://em.rdcu.be/wf/click?upn=lMZy1lernSJ7apc5DgYM8cHCDk9d7lPi-2FGSD8-2FGwsX8-3D_MOZQk9l3-2B-2FRN6gOCb2khH81Uxa-2FL1tydpfhVPbOe5HqrSM8G9BSdx1nNSKS8X-2FF7BYN0xSNf3Sh-2BPs2cD19Fas-2FBaZuv-2FOBqYKW98wvrkY8piivmiKUzprjFOFEMQ8nkcdUO39NMyDfeRg3rJKtw29tO4JKudyDILXr2I7Z8q1TsqaEG4mi8T2oiSbQXHt-2B71RbEGBuVMwVdRqJZhELyKJyN0k9PpXuylLCfUsfA7ALcuTM8lrFXckivaThqyRr7Pwk4NyIzCTWEYsNZP2BeUQ-3D-3D">https://rdcu.be/7aPz</a> <br/></p><p>Funding for this research was provided by the U.S. Department of Energy (DE-AC02-05-CH11231). Use of the Advanced Photon Source at the Argonne National Laboratory was supported by the U.S. Department of Energy (DE-AC02-06CH11357).<br/></p><div><div class="cstm-section"><h3>Young-Shin Jun<br/></h3><div style="text-align: center;"> <strong><a href="/Profiles/Pages/Young-Shin-Jun.aspx"><img src="/Profiles/PublishingImages/Jun_Young-Shin.jpg?RenditionID=3" alt="Lan Yang" style="margin: 5px;"/></a> <br/></strong></div><ul style="text-align: left;"><li>Professor</li><li>Expertise: Environmental nanochemistry to address challenges in energy and water by controlling nucleation and reactions at water-solid interfaces<br/></li></ul><p style="text-align: center;"> <a href="/Profiles/Pages/Young-Shin-Jun.aspx">>> View Bio</a><br/></p></div></div>An atomic force microscopy image of nucleated calcium carbonate nanoparticles (showing as white dots) on a quartz surface. The scan size of the image is 1.3 x 1.3 μm2.Beth Miller 2018-09-19T05:00:00ZYoung-Shin Jun and her lab used state-of-the-art imaging techniques to discover how calcium carbonate nanoparticles nucleate, an important process to manufacture carbonate nanomaterials.<p>​Research makes breakthrough in measuring nanoparticle properties with more precision<br/></p>
https://engineering.wustl.edu/news/Pages/Research-comes-full-circle-at-International-Aerosol-Conference.aspx925Research comes full circle at International Aerosol Conference<img alt="" src="/news/PublishingImages/IMG_3915-e1536767216404.jpg?RenditionID=1" style="BORDER:0px solid;" /><div id="__publishingReusableFragmentIdSection"><a href="/ReusableContent/36_.000">a</a></div><p>Recently, more than 1,500 of the world’s preeminent aerosol scientists gathered in St. Louis for the 10<span style="box-sizing: inherit; font-size: 14.399999618530273px; line-height: 0; vertical-align: baseline; top: -0.5em; height: 0px; bottom: 1ex;">th</span> International Aerosol Conference (IAC). Held every four years — and only every 12 years in the United States — the event took place Sept. 2-7 at the Americas Center. The conference was opened by Chancellor Mark S. Wrighton, who welcomed the attendees from 48 different countries to St. Louis.</p><p>Washington University in St. Louis has one of the country’s leading aerosol centers (Center for Aerosol Science and Engineering, or CASE), and its faculty in the School of Engineering & Applied Science helped organize the program by presenting research and talks centered aerosol science and engineering. Eight faculty members and their students had more than 65 presentations at the conference.<br/></p><p>“This is a wide-ranging and fascinating field,” said Pratim Biswas, assistant vice chancellor,  chair of the Department of Energy, Environmental & Chemical Engineering and the Lucy & Stanley Lopata Professor at the School of Engineering & Applied Science, who chaired the conference. “Washington University is leading the way when it comes to this important focus of study, and we were so pleased to host some of the world’s best aerosol experts here in St. Louis for IAC 2018.”</p> <p>While the word aerosol may immediately bring to mind a can of hairspray or paint, this scientific research focuses on so much more than an application system. Aerosol science and engineering deals with the formation, growth, transport and deposition of small particles. It is considered an “enabling discipline,” encompassing everything from fighting smog and understanding impacts on climate and mitigation impacts, to designing better drug delivery for cancer patients, better design of solar cells, and even more efficient crop fertilization techniques falls under the field.</p><p>And it’s a field in which Washington University engineers have been at the forefront for more than eight decades.</p><h4>Headlights at high noon</h4> <figure class="wp-caption alignleft" style="box-sizing: inherit; display: inline; margin: 0px 1.5em 1.5em 0px; float: left; max-width: 100%; padding: 0px; border: none; background-image: none; caret-color: #3c3d3d; color: #3c3d3d; font-family: "source sans pro", "helvetica neue", helvetica, arial, sans-serif; font-size: 19.200000762939453px; width: 235px;"> <img data-attachment-id="293723" data-permalink="https://source.wustl.edu/2018/09/research-comes-full-circle-at-international-aerosol-conference/stl-smoke/" data-orig-file="https://source.wustl.edu/wp-content/uploads/2018/09/STL-smoke.jpg" data-orig-size="1648,2100" data-comments-opened="0" data-image-meta="{"aperture":"0","credit":"","camera":"","caption":"\"Black Tuesday.\" View looking at the Civil Courts building while smoke pollution blots out the sun at mid-day. Photograph, 1939. Missouri History Museum Photographs and Prints collections. St. Louis Views Collection. n30962.","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"0"}" data-image-title="STL smoke" data-medium-file="https://source.wustl.edu/wp-content/uploads/2018/09/STL-smoke-235x300.jpg" data-large-file="https://source.wustl.edu/wp-content/uploads/2018/09/STL-smoke-804x1024.jpg" class="size-medium wp-image-293723" src="https://source.wustl.edu/wp-content/uploads/2018/09/STL-smoke-235x300.jpg" alt="" style="box-sizing: inherit; border-width: 0px; width: 235px; display: block; margin: 5px;"/> <figcaption class="wp-caption-text" style="box-sizing: inherit; margin-bottom: 0px; font-size: 1rem; font-style: italic; line-height: 1.333; color: #626464; margin-top: 0.25em;">In November of 1939, the smog in St. Louis was so thick, the sun was blotted from view at mid-day. (Photo: Courtesy of Missouri Historical Society)</figcaption></figure> <p>Nearly 80 years ago, St. Louis faced an environmental crisis unlike any the city had ever weathered: Thick, choking smoke had long been a problem for the city due to generations of St. Louisans routinely burning coal to keep their homes warm. By the 1930s, the problem had grown to epidemic proportions. Thick smoke routinely blanketed the city, making it necessary at time to turn on headlights and streetlights in the middle of the day.</p><p>As the smog worsened, Washington University engineers of the day studied St. Louis’ dirty air, its effects and possible mitigation techniques. Raymond Tucker, then-chair of the mechanical engineering department, eventually became the city smoke commissioner, putting policies into place to cut the smog, including forcing business to burn cleaner coal and creating emissions standards. These measures resulted in much cleaner, safer air for the city. Tucker eventually became mayor, serving the city from 1953-1965..<br/></p><p>Biswas said Washington University’s role now—as it was then—is equally important.</p><p>“Around the globe, there are still air pollution issues,” he said. “In the 1930s, our university helped pioneer solutions for cleaner air. That is what we hope will happen around the world, and it is still our goal some 80 years later. People are very concerned and want solutions. There are rather innovative approaches being developed by aerosol scientists, and we saw examples presented at the IAC.”</p> <figure class="wp-caption alignright" style="box-sizing: inherit; display: inline; margin: 0px 1.7638888889em 1.5em 1.5em; float: right; max-width: 100%; padding: 0px; border: none; background-image: none; width: 300px; caret-color: #3c3d3d; color: #3c3d3d; font-family: "source sans pro", "helvetica neue", helvetica, arial, sans-serif; font-size: 19.200000762939453px;"> <img data-attachment-id="293525" data-permalink="https://source.wustl.edu/2018/09/research-comes-full-circle-at-international-aerosol-conference/180904_jaa_iac_pratim_biswas_0035/" data-orig-file="https://source.wustl.edu/wp-content/uploads/2018/09/180904_jaa_iac_pratim_biswas_0035.jpg" data-orig-size="1500,1000" data-comments-opened="0" data-image-meta="{"aperture":"5.6","credit":"Joe Angeles\/Washington Universit","camera":"Canon EOS 5D Mark IV","caption":"9.4.2018--Fuchs Award Presentation at the IAC Conference--From right:\rPratim Biswas, 2018 Fuchs Memorial Award winner;\rUrs Baltensperger, GAeF, Chair of the Fuchs Award Committee.\rPhotos by Joe Angeles\/Washington University","created_timestamp":"1536068781","copyright":"WashU Photos","focal_length":"105","iso":"2500","shutter_speed":"0.01","title":"","orientation":"1"}" data-image-title="180904_jaa_iac_pratim_biswas_0035" data-medium-file="https://source.wustl.edu/wp-content/uploads/2018/09/180904_jaa_iac_pratim_biswas_0035-300x200.jpg" data-large-file="https://source.wustl.edu/wp-content/uploads/2018/09/180904_jaa_iac_pratim_biswas_0035-1024x683.jpg" class="wp-image-293525 size-medium" src="https://source.wustl.edu/wp-content/uploads/2018/09/180904_jaa_iac_pratim_biswas_0035-300x200.jpg" alt="" style="box-sizing: inherit; border-width: 0px; width: 300px; display: block; margin: 5px;"/> <figcaption class="wp-caption-text" style="box-sizing: inherit; margin-bottom: 0px; font-size: 1rem; font-style: italic; line-height: 1.333; color: #626464; margin-top: 0.25em;">Pratim Biswas (right) receives the 2018 Fuchs Memorial Award from Urs Baltensperger, chair of the Fuchs Award Committee during the International Aerosols Conference. (Photo: Joe Angeles/Washington University)</figcaption></figure> <h4>Recognition for research<br/></h4><p>The conference also drew special recognition for Washington University.  Biswas received the highest honor given to aerosol scientists, the Fuchs Award.  The award is given out once in four years to a researcher who has made exemplary contributions in aerosol science and technology.</p><p>Two CASE alumni also received special honors: the American Association for Aerosol Research honored Chris Hogan with the Whitby Award; the German Aerosol Association presented Jingkun Jiang its Smoluchowski Award. Several Washington University students also won best poster awards.</p><p>Outside of research talks and presentations at the conference, Biswas and his School of Engineering & Applied Science colleagues also served as St. Louis and Washington University ambassadors. More than 300 attendees took tours of the school’s engineering labs, and enjoyed a reception hosted by Dean Aaron Bobick. Tours of Cortex and other places of interest also were arranged, and St. Louis Mayor Lyda Krewson proclaimed it “Aerosol Science and Engineering Week” in the city.<br/></p> <SPAN ID="__publishingReusableFragment"></SPAN> <p> <br/> </p><p><br/></p><p>​<br/></p><div><div class="cstm-section"><h3>Pratim Biswas<br/></h3><div style="text-align: center;"> <strong><a href="/Profiles/Pages/Lan-Yang.aspx"><img src="/Profiles/PublishingImages/Biswas_Pratim.JPG?RenditionID=3" alt="Pratim Biswas" style="margin: 5px;"/></a> <br/></strong></div><ul style="text-align: left;"><li>Assistant Vice Chancellor & Department Chair<br/> Lucy & Stanley Lopata Professor</li><li>Expertise: Aerosol science and engineering with applications in energy and environmental nanotechnology, nanoparticle synthesis, advanced material synthesis, pharmaceuticals and theranostics, medicine, biological systems, solar energy utilization, electronics, air pollution control, sensors, atmospheric issues, thermal sciences<br/></li></ul><p style="text-align: center;"> <a href="/Profiles/Pages/Pratim-Biswas.aspx">>> View Bio</a><br/></p></div></div>Washington University engineers hosted some 300 attendees of the International Aerosol Conference in a visit to the Danforth Campus earlier this month. Here, they're touring the Aerosol and Air Quality Research Lab in Brauer Hall.Erika Ebsworth-Gooldhttps://source.wustl.edu/2018/09/research-comes-full-circle-at-international-aerosol-conference/2018-09-12T05:00:00ZRecently, more than 1,500 of the world’s preeminent aerosol scientists gathered in St. Louis for the 10th International Aerosol Conference (IAC). The event is held every four years, and only every 12 years in the United States.<p>The School of Engineering & Applied Science hosts some of the world’s best aerosol experts from 48 different countries here in St. Louis.<br/></p>
https://engineering.wustl.edu/news/Pages/Focused-delivery-for-brain-cancers.aspx917Focused delivery for brain cancers<div class="youtube-wrap"><div class="iframe-container"> <iframe width="854" height="480" frameborder="0" src="https://www.youtube.com/embed/c2qTVXxIdyU"></iframe> <br/> <br/> <br/></div></div><img alt="" src="/news/PublishingImages/Hong-Chen-brain.jpg?RenditionID=1" style="BORDER:0px solid;" /><div id="__publishingReusableFragmentIdSection"><a href="/ReusableContent/36_.000">a</a></div><p>​A person’s brainstem controls some of the body’s most important functions, including heart beat, respiration, blood pressure and swallowing. Tumor growth in this part of the brain is therefore twice as devastating. Not only can such a growth disrupt vital functions, but operating in this area is so risky, many medical professionals refuse to consider it as an option.</p><p>New, interdisciplinary research from Washington University in St. Louis has shown a way to target drug delivery to just that area of the brain using noninvasive measures, bolstered by a novel technology: focused ultrasound.</p><p>The research comes from the lab of <a href="/Profiles/Pages/Hong-Chen.aspx">Hong Chen</a>, assistant professor of biomedical engineering in the School of Engineering & Applied Science and assistant professor of radiation oncology at Washington University School of Medicine in St. Louis. Chen has developed a novel way in which ultrasound and its contrast agent — consisting of tiny bubbles — can be paired with intranasal administration, to direct a drug to the brainstem and, potentially, any other part of the brain.<br/></p><p></p><p>The research, which included faculty from the Mallinckrodt Institute of Radiology and the Department of Pediatrics at the School of Medicine, along with faculty from the Department of Energy, Environmental & Chemical Engineering in the School of Engineering & Applied Science, was published online this week and will be in the Sept. 28 issue of the <a href="https://www.sciencedirect.com/science/article/pii/S0168365918304140">Journal of Controlled Release</a>.</p><p>This technique may bring medicine one step closer to curing brain-based diseases such as diffuse intrinsic pontine gliomas (DIPG), a childhood brain cancer with a five-year survival rate of a scant two percent, a dismal prognosis that has remained unchanged over the past 40 years. (To add perspective, the most common childhood cancer, acute lymphoblastic leukemia, has a <a href="https://www.cancer.gov/types/childhood-cancers/child-adolescent-cancers-fact-sheet">five-year survival rate of nearly 90 percent.</a>)<br/></p><p></p><p>“Each year in the United States, there are no more than 300 cases,” Chen said. “All pediatric diseases are rare; luckily, this is even more rare. But we cannot count numbers in this way, because for kids that have this disease and their families, it is devastating.”</p><p>Chen’s technique combines Focused UltraSound with IntraNasal delivery, (FUSIN). The intranasal delivery takes advantage of a unique property of the olfactory and trigeminal nerves: they can carry nanoparticles directly to the brain, bypassing the blood brain barrier, an obstacle to drug delivery in the brain.</p><p>This unique capability of intranasal delivery was demonstrated last year by co-authors<a href="https://sites.wustl.edu/rameshraliya"> Ramesh Raliya</a>, research scientist, and<a href="/Profiles/Pages/Pratim-Biswas.aspx"> Pratim Biswas</a>, assistant vice chancellor and chair of the Department of Energy, Environmental & Chemical Engineering and the Lucy & Stanley Lopata Professor, in their<a href="https://www.nature.com/articles/srep44718"> 2017 publication in Scientific Reports</a>.</p><p>“At the beginning, I couldn’t even believe this could work,” Hong said of delivering drugs to the brain intranasally. “I thought our brains are fully protected. But these nerves actually directly connect with the brain and provide direct access to the brain.”</p><p>While nasal brain drug delivery is a huge step forward, it isn’t yet possible to target a drug to a specific area. Chen’s targeted ultrasound technique is addressing that problem.</p><p>When doing an ultrasound scan, the contrast agent used to highlight images is composed of microbubbles. Once injected into the bloodstream, the microbubbles behave like red blood cells, traversing the body as the heart pumps.</p><p>Once they reach the site where the ultrasound wave is focused, they do something unusual.</p><p>“They start to expand and contract,” Chen said. As they do so, they act as a pump to the surrounding blood vessels as well as the perivascular space — the space surrounding the blood vessels.</p><p>“Consider the blood vessels like a river,” Chen said. “The conventional way to deliver drugs is to dump them in the river.” In other parts of the body, the banks of the river are a bit “leaky,” Chen said, allowing the drugs to seep into the surrounding tissue. But the blood brain barrier, which forms a protective layer around blood vessels in the brain, prevents this leakage, particularly in the brains of  young patients, such as those with with DIPG.</p><p>“We will deliver the drug from the nose to directly outside the river,” Chen said, “in the perivascular space.”</p><p>Then, once ultrasound is applied at the brain stem, the microbubbles will begin to expand and contract. The oscillating microbubbles push and pull, pumping the drug toward the brainstem. This technique also addresses the problem of drug toxicity — the drugs will go directly to the brain instead of circulating through the whole body. In collaboration with <a href="https://www.mir.wustl.edu/research/research-laboratories/radiological-chemistry-and-imaging-laboratory-rcil/people/yongjian-liu">Yongjian Liu</a>, associate professor of radiology, and <a href="https://www.mir.wustl.edu/research/research-laboratories/radiological-chemistry-and-imaging-laboratory-rcil/people/bio-template3/yuan-chuan-tai">Yuan-Chuan Tai</a>, associate professor of radiology, Chen used positron emission tomography (PET scan) to verify that there was minimal accumulation of intranasal-administered nanoparticles in major organs, including lungs, liver, spleen, kidney and heart.</p><p>So far, Chen’s lab has had success using their technique in mice for the delivery of gold nanoclusters made by the team led by Liu.</p><p>“The next step is to demonstrate the therapeutic efficacy of FUSIN in the delivery of chemotherapy drugs for the treatment of DIPG,” said <a href="https://chenultrasoundlab.wustl.edu/people/dezhuang-summer-ye/">Dezhuang Ye</a>, lead author of the paper, who is Chen’s graduate student from the <a href="https://mems.wustl.edu/Pages/default.aspx">Department of Mechanical Engineering & Materials Science</a>. The lab has also teamed up with Biswas to develop a new aerosol nasal delivery device to scale up the technique from a mouse to a large animal model.</p><p>Chen’s lab collaborated on this research with pediatric neuro-oncologist <a href="http://pediatrics.wustl.edu/faculty/rubin_joshua_b">Joshua Rubin</a>, MD, PhD, professor of pediatrics at the School of Medicine who treats patients at St. Louis Children’s Hospital. Chen said the team hopes to translate the findings of this study into clinical trials for children with DIPG.</p><p>There are difficulties ahead, but Chen believes researchers will need to continue to innovate when it comes to solving such a difficult problem as treating DIPG.<br/></p><span><hr/></span><p>Dezhuang Ye, Xiaohui Zhang, Yimei Yue, RameshRaliya, Pratim Biswas, Sara Taylor, Yuan-chuan Tai, Joshua B.Rubin, Yongjian Liu, Hong Chen. <a href="https://www.sciencedirect.com/science/article/pii/S0168365918304140#!">Focused ultrasound combined with microbubble-mediated intranasal delivery of gold nanoclusters to the brain</a>. 28 September 2018;  <a href="http://doi.org/10.1016/j.jconrel.2018.07.020" rel="nofollow">doi.org/10.1016/j.jconrel.2018.07.020</a><a href="https://www.sciencedirect.com/science/article/pii/S0168365918304140#!" name="bau0050"></a></p><p>This work was supported by a grant from the American Cancer Society, grant number <a href="https://www.sciencedirect.com/science/article/pii/S0168365918304140#gts0005">IRG-58-010-61-1</a>. It was also supported by the Children’s Discovery Institute of Washington University and St. Louis Children’s Hospital, grant number <a href="https://www.sciencedirect.com/science/article/pii/S0168365918304140#gts0010">MC-II-2017-661</a>. Ramesh Raliya was partially supported by the CMMN Grant NIH-NCI <a href="https://www.sciencedirect.com/science/article/pii/S0168365918304140#gts0015">U54CA199092</a>. We thank Professor Rajiv Chopra and Chenchen Bing from the University of Texas Southwestern for providing us with the ultrasound <a title="Learn more about Transducer" href="https://www.sciencedirect.com/topics/materials-science/transducer">transducer</a> and technical assistance in setting up the second ultrasound system used in this study.</p><SPAN ID="__publishingReusableFragment"></SPAN><p><br/></p><p>​</p><span><div class="cstm-section"><h3>A targeted inspiration</h3><div> <strong></strong></div><div><div rtenodeid="190" style="text-align: center;"><img src="/Profiles/PublishingImages/Chen_Hong_7_15_06.jpg?RenditionID=3" alt="" style="margin: 5px;"/><br/></div><div><br/></div><div rtenodeid="182"><span class="ms-rteStyle-References">Hong Chen’s lab collaborated on this research with Joshua Rubin, MD, PhD, professor of pediatrics at the School of Medicine. And it all started with a couple of colleagues talking one day:</span></div><div rtenodeid="183"><br rtenodeid="184" class="ms-rteStyle-References"/></div><div rtenodeid="185"><span class="ms-rteStyle-References">“My work in this field started with a conversation with him,” Chen said. “He said, ‘Wow, this would be a perfect technique for treating this deadly disease.’ Without him to point me in this direction, I probably wouldn’t have known this application existed.<br rtenodeid="187"/></span></div><div rtenodeid="188"><br rtenodeid="189" class="ms-rteStyle-References"/></div><div><span class="ms-rteStyle-References">“That’s why I consider the Washington University environment, and the School of Engineering & Applied Science, so unique. It provides you so much opportunity to work with people from different backgrounds. It allowed me to expand my research scope and to be able to work on clinically relevant questions.”</span><br rtenodeid="193"/></div></div></div></span><p><br/></p>Brandie Jeffersonhttps://source.wustl.edu/2018/09/focused-delivery-for-brain-cancers/2018-09-04T05:00:00ZResearchers in engineering and medicine work toward a more focused drug delivery system that could target tumors lodged in the brainstem, the body’s most precious system.<p>​Interdisciplinary research brings together imaging, aerosols and pediatric neuro oncology to fight tumors<br/></p>Y
https://engineering.wustl.edu/news/Pages/Chakrabarty-to-receive-early-career-award-from-AGU.aspx906Chakrabarty to receive early career award from AGU<img alt="" src="/Profiles/PublishingImages/Chakrabarty_Rajan.jpg?RenditionID=2" width="470" style="BORDER:0px solid;" /><p>​</p><p>Rajan Chakrabarty, assistant professor of energy, environmental & chemical engineering, has been selected to receive the Global Environmental Change Early Career Award from the American Geophysical Union (AGU). </p><p> </p><p>The award honors scientists for enlightening our understanding of the Earth and its atmosphere and oceans, and of the solar system and exoplanets. Honorees have contributed to that health and well-being through their scientific advancements and outstanding service to the science and to AGU. Chakrabarty will be recognized at AGU's Fall Meeting in Washington, D.C. </p><p> </p><p> </p><p><br/></p>Rajan Chakrabarty2018-08-23T05:00:00ZRajan Chakrabarty will received an early career award for his work in global environmental change.
https://engineering.wustl.edu/news/Pages/Bigger-proteins,-stronger-threads-Biosynthetic-spider-silk-Fuzhong-Zhang-Biomacromolecules.aspx905Bigger proteins, stronger threads: Synthetic spider silk<img alt="Biosynthetic silk" src="/news/PublishingImages/Fibers-760x569.jpg?RenditionID=1" style="BORDER:0px solid;" /><p> <span style="box-sizing: inherit;">Spider silk is among the strongest and toughest materials in the natural world, as strong as some steel alloys with a toughness even greater than bulletproof Kevlar. Spider silk’s unmatched combination of strength and toughness have made this protein-based material desirable for many applications ranging from super thin surgical sutures to projectile resistant clothing. Unfortunately, due to spiders’ territorial and cannibalistic nature, their silk has been impossible to mass produce, so practical applications have yet to materialize.</span></p><p> <span style="box-sizing: inherit;">Scientists have been able to create some forms of synthetic spider silk, but have been unable to engineer a material that included most if not all of the natural silk’s traits.</span></p><p> <span style="box-sizing: inherit;">Until now.</span></p> <figure class="wp-caption alignright" style="box-sizing: inherit; display: inline; margin: 0px 0px 1.5em 1.5em; float: right; max-width: 100%; padding: 0px; border: none; background-image: none; caret-color: #3c3d3d; color: #3c3d3d; font-family: "source sans pro", "helvetica neue", helvetica, arial, sans-serif; font-size: 19.2px; width: 171px;"><img data-attachment-id="127070" data-permalink="https://source.wustl.edu/2016/01/zhang-honored-for-research-by-biotechnology-bioengineering-journal/zhang_fuzhong-2/" data-orig-file="https://source.wustl.edu/wp-content/uploads/2016/01/Zhang_Fuzhong-1.jpg" data-orig-size="600,596" data-comments-opened="0" data-image-meta="{"aperture":"0","credit":"","camera":"","caption":"","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"1"}" data-image-title="Zhang-Fuzhong" data-image-description="<p>Fuzhong Zhang Engineering</p>" data-medium-file="https://source.wustl.edu/wp-content/uploads/2016/01/Zhang_Fuzhong-1-300x298.jpg" data-large-file="https://source.wustl.edu/wp-content/uploads/2016/01/Zhang_Fuzhong-1.jpg" class="wp-image-127070" src="https://source.wustl.edu/wp-content/uploads/2016/01/Zhang_Fuzhong-1-300x298.jpg" alt="Fuzhong Zhang" style="box-sizing: inherit; border-width: 0px; width: 171px; display: block; margin: 5px;"/><figcaption class="wp-caption-text" style="box-sizing: inherit; margin-bottom: 0px; font-size: 1rem; font-style: italic; line-height: 1.333; color: #626464; margin-top: 0.25em;">Zhang</figcaption></figure> <p> <span style="box-sizing: inherit;">Researchers in the <a href="/" style="box-sizing: inherit;">School of Engineering & Applied Science</a> at Washington University in St. Louis have engineered bacteria that produce a biosynthetic spider silk with performance on par with its natural counterparts in all of the important measures. And they’ve discovered something exciting about the possibilities ahead.</span></p><p> <span style="box-sizing: inherit;">The new research, published Aug. 20 in </span><a href="https://pubs.acs.org/doi/full/10.1021/acs.biomac.8b00980" style="box-sizing: inherit;">Biomacromolecules</a><span style="box-sizing: inherit;">, reveals that the tensile strength and toughness of spider silk remains positively correlated with its molecular weight — the bigger the molecule, the stronger the silk — even in synthetic silk with a weight nearly twice that of the previous record-holder.</span></p><p> <span style="box-sizing: inherit;">“People already knew about this correlation, but only with smaller-sized proteins. We found that even at this large size, there is still a very good correlation,” said <a href="/Profiles/Pages/Fuzhong-Zhang.aspx?_ga=2.10524916.1195508787.1534776603-757045394.1533662676" style="box-sizing: inherit;">Fuzhong Zhang</a>, associate professor in the School of Engineering & Applied Science.</span></p><p> <span style="box-sizing: inherit;">One of the biggest historical challenges creating a biosynthetic spider silk has been creating a large enough protein. The challenge was so big, in fact, it required a whole new approach.</span></p><p> <span style="box-sizing: inherit;">“We started with what others had done, making a genetically repeated sequence,” said Christopher Bowen, a <g class="gr_ gr_79 gr-alert gr_gramm gr_inline_cards gr_run_anim Punctuation multiReplace" id="79" data-gr-id="79">PhD</g> student in Zhang’s lab. The DNA sequence was modeled after the sequence in spiders that is responsible for creating the silk protein. In theory, the more repetitions of the sequence, the bigger the resulting protein.</span></p> <figure class="wp-caption alignright" style="box-sizing: inherit; display: inline; margin: 0px 1.76389em 1.5em 1.5em; float: right; max-width: 100%; padding: 0px; border: none; background-image: none; width: 300px; caret-color: #3c3d3d; color: #3c3d3d; font-family: "source sans pro", "helvetica neue", helvetica, arial, sans-serif; font-size: 19.2px;"><img data-attachment-id="289348" data-permalink="https://source.wustl.edu/2018/08/bigger-proteins-stronger-threads-synthetic-spider-silk/silk-fiber2/" data-orig-file="https://source.wustl.edu/wp-content/uploads/2018/08/silk-fiber2.jpg" data-orig-size="606,522" data-comments-opened="0" data-image-meta="{"aperture":"0","credit":"","camera":"","caption":"","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"1"}" data-image-title="silk fiber2" data-image-description="<p>Silk fiber created by bacteria.</p>" data-medium-file="https://source.wustl.edu/wp-content/uploads/2018/08/silk-fiber2-300x258.jpg" data-large-file="https://source.wustl.edu/wp-content/uploads/2018/08/silk-fiber2.jpg" class="wp-image-289348 size-thumbnail" src="https://source.wustl.edu/wp-content/uploads/2018/08/silk-fiber2-300x300.jpg" alt="Close up of silk fiber" style="box-sizing: inherit; border-width: 0px; width: 300px; display: block; margin: 5px;"/><figcaption class="wp-caption-text" style="box-sizing: inherit; margin-bottom: 0px; font-size: 1rem; font-style: italic; line-height: 1.333; color: #626464; margin-top: 0.25em;">Biosynthetic silk (Photo: Christopher Bowen)</figcaption></figure> <p> <span style="box-sizing: inherit;">After the DNA sequence reaches a certain size, however, “the bacteria can’t handle it, they chop the sequence into smaller pieces,” Bowen said. It’s a problem that has been encountered many times in previous efforts. To get around this long-standing obstacle, Bowen and co-authors added a short genetic sequence to the silk DNA that promotes a chemical reaction between the resulting proteins, fusing them together to form an even bigger protein, bigger than has ever been produced and purified before.</span></p><p>“We made proteins basically twice as large as anyone’s been able to make before,” Bowen said. Their silk protein chains are 556 kDa. Previously, the largest biosynthetic spider silk protein was 285 kiloDaltons (kDa), an atomic unit of measurement. Even natural dragline silk proteins <g class="gr_ gr_74 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar only-ins replaceWithoutSep" id="74" data-gr-id="74">tend</g> be around 370 kDa, although there are a few, bigger outliers.</p><p> <span style="box-sizing: inherit;">Bowen and co-authors subsequently spun their exceptionally large biosynthetic silk proteins into fibers about a tenth the diameter of a human hair and tested their mechanical properties. This biosynthetic silk is the first to replicate natural spider silk in terms <g class="gr_ gr_64 gr-alert gr_gramm gr_inline_cards gr_run_anim Punctuation only-del replaceWithoutSep" id="64" data-gr-id="64">of:</g> tensile strength (the maximum stress needed to break the fiber), toughness (the total energy absorbed by the fiber before breaking), as well as other mechanical parameters such as elastic modulus and extensibility</span><span style="box-sizing: inherit;">.</span></p> <figure class="wp-caption alignright" style="box-sizing: inherit; display: inline; margin: 0px 1.76389em 1.5em 1.5em; float: right; max-width: 100%; padding: 0px; border: none; background-image: none; width: 300px; caret-color: #3c3d3d; color: #3c3d3d; font-family: "source sans pro", "helvetica neue", helvetica, arial, sans-serif; font-size: 19.2px;"><img data-attachment-id="289459" data-permalink="https://source.wustl.edu/2018/08/bigger-proteins-stronger-threads-synthetic-spider-silk/fibers/" data-orig-file="https://source.wustl.edu/wp-content/uploads/2018/08/Fibers.jpg" data-orig-size="929,696" data-comments-opened="0" data-image-meta="{"aperture":"2.4","credit":"","camera":"iPhone 5c","caption":"","created_timestamp":"1493215251","copyright":"","focal_length":"4.12","iso":"64","shutter_speed":"0.05","title":"","orientation":"1"}" data-image-title="Fibers" data-image-description="<p>Biosynthetic silk fibers created by bacteria</p>" data-medium-file="https://source.wustl.edu/wp-content/uploads/2018/08/Fibers-300x225.jpg" data-large-file="https://source.wustl.edu/wp-content/uploads/2018/08/Fibers.jpg" class="wp-image-289459 size-thumbnail" src="https://source.wustl.edu/wp-content/uploads/2018/08/Fibers-300x300.jpg" alt="Biosynthetic silk fibers" style="box-sizing: inherit; border-width: 0px; width: 300px; display: block; margin: 5px;"/><figcaption class="wp-caption-text" style="box-sizing: inherit; margin-bottom: 0px; font-size: 1rem; font-style: italic; line-height: 1.333; color: #626464; margin-top: 0.25em;">Engineers at Washington University have created bacteria that produce biosynthetic silk that’s as strong as the real thing. (Photo: Christopher Bowen)</figcaption><figcaption class="wp-caption-text" style="box-sizing: inherit; margin-bottom: 0px; font-size: 1rem; font-style: italic; line-height: 1.333; color: #626464; margin-top: 0.25em;"><br/></figcaption></figure> <p> <span style="box-sizing: inherit;">Going forward, Zhang’s lab is looking to work toward positioning biosynthetic silk fibers to replace some of the <g class="gr_ gr_53 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar multiReplace" id="53" data-gr-id="53">myriad</g> of petroleum-based synthetic fibers used across <g class="gr_ gr_52 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar only-ins replaceWithoutSep" id="52" data-gr-id="52">industry</g>.</span></p><p> <span style="box-sizing: inherit;">“We will continue to work on making the process more scalable and economical by making it easier to handle, reducing the <g class="gr_ gr_51 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar multiReplace" id="51" data-gr-id="51">amount</g> of chemicals needed, and increasing the robustness and efficiency,” Zhang said.</span></p><p> <span style="box-sizing: inherit;">And the Zhang group also plans to further explore the limits of their new approach. In addition to producing the first biosynthetic silk fibers to fully replicate the performance of natural spider silk, their work strongly suggests that the strength and toughness of these fibers will continue to increase if even larger proteins can be produced.</span></p> <br/> <br/> <br/> <hr/> <p>The School of Engineering & Applied Science at Washington University in St. Louis focuses intellectual efforts through a new convergence paradigm and builds on strengths, particularly as applied to medicine and health, energy and environment, entrepreneurship and security. With 96.5 tenured/tenure-track and 28 additional full-time <g class="gr_ gr_60 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar multiReplace" id="60" data-gr-id="60">faculty</g>, 1,300 undergraduate students, 1,200 graduate students and 20,000 alumni, we are working to leverage our partnerships with academic and industry partners — across disciplines and across the world — to contribute to solving the greatest global challenges of the 21st century.<br/></p><p><br/>This work was supported by a <a href="https://www.wpafb.af.mil/News/Article-Display/Article/818861/afosr-awards-grants-to-57-scientists-and-engineers-through-its-young-investigat/">Young Investigator Program</a> from the Air Force Office of Scientific Research, grant no. FA95501510174; an <a href="https://www.nasa.gov/feature/nasa-2015-space-technology-research-opportunities-for-early-career-faculty">Early Career Faculty grant</a> from NASA's Space Technology Research Grants Program, grant no. NNX15AU45G; and the <a href="https://www.nih.gov/grants-funding">National Institutes of Health</a>, grant no. P41EB002520.</p><p> </p><p> </p><p><br/><strong></strong></p> <br/><p> <br/> </p> <span> <div class="cstm-section"><h3>Fuzhong Zhang<br/></h3><div style="text-align: center;"> <img src="/Profiles/PublishingImages/Zhang_Fuzhong.jpg?RenditionID=3" alt="" style="margin: 5px;"/> <br/> </div><div><ul style="padding-left: 20px; color: #343434;"><li>Associate Professor of Energy, Environmental & Chemical Engineering<br/></li><li>Expertise: Synthetic biology approaches to produce advanced biofuels, chemicals, and materials from sustainable resources<br/></li></ul><p style="color: #343434; text-align: center;"> <a href="/Profiles/Pages/Fuzhong-Zhang.aspx?_ga=2.69924944.1195508787.1534776603-757045394.1533662676">View Bio</a><br/></p></div></div></span> <p> <br/> </p>Engineers at Washington University have created bacteria that produce biosynthetic silk that’s as strong as the real thing (Photo: Christopher Bowen)Brandie Jeffersonhttps://source.wustl.edu/2018/08/bigger-proteins-stronger-threads-synthetic-spider-silk/2018-08-21T05:00:00ZScientists have been able to create some forms of synthetic spider silk, but have been unable to engineer a material that included most if not all of the natural silk’s traits. Until now.<p>Engineering scientists use bacteria to create biosynthetic silk threads stronger and tougher than before<br/></p>