Category: Recent News
Joint Research Focused on Medical Imaging and Image-Guided Interventions
By Mark Dwortzan
Boston University College of Engineering Assistant Professor Darren Roblyer (BME) and Brigham & Women’s Hospital radiologist Srinivisan Mukundan are exploring a strategy that combines a new optical imaging device developed by Roblyer with emerging magnetic resonance imaging (MRI) techniques to probe malignant brain tumors during chemotherapy treatment. Their research could enable clinicians to monitor the effectiveness of chemotherapy over the course of treatment and implement changes to chemotherapy drugs and dose levels as needed.
The project is one of five now receiving funding through an ongoing partnership between Boston University and Brigham & Women’s Hospital. On September 12 at the BU Photonics Center, Dean Kenneth R. Lutchen and Dr. Steven Seltzer, Chair of the BWH Department of Radiology, announced the second year of the partnership, which has already provided one year of seed funding to projects ranging from image-guided cancer drug delivery to early detection of heart disease.
“The goal is to leverage synergies between Brigham & Women’s Hospital’s Radiology Department in imaging and image-guided interventions with the College of Engineering’s strengths in developing new materials and technologies as well as novel techniques for processing images and large data sets,” said Associate Professor Tyrone Porter (ME, BME, MSE), who is coordinating the partnership. “The hope is to stimulate research collaborations between the two campuses and develop a National Institutes of Health training program in clinical imaging and image-guided interventions.”
The brainchild of Lutchen and Seltzer, the BU-BWH partnership brings together world-class expertise and equipment from Boston University entities such as the BU Photonics Center and the BU Center for Nanoscience & Nanobiotechnology, and from the BWH Department of Radiology, home to the National Institutes of Health’s National Center for Image-Guided Therapy and the Advanced Multimodality Image Guided Operating Suite (AMIGO). Joint research between the two campuses could result in less invasive, more accurate medical imaging and image-guided interventions.
“There’s no question that in so many dimensions, imaging is at the foundation of a tremendous amount of potential breakthroughs in medical discoveries and practice, but there are huge challenges from a scientific and technical point of view,” said Lutchen. “We’ve got tons of interested students and faculty here that need and want to use imaging technologies to address interesting and important questions.”
First-round projects include the engineering of a new “molecular imaging” MRI contrast agent for detecting early calcification of the aortic valve; the combination of ultrasound and MR data to evaluate the elastic properties of tissues, which are associated with pathological indicators of disease; a clinical decision support system for patient-specific cancer diagnosis and management; and ultrasound-guided delivery of chemotherapy drug-laden nanoparticles to metastasized lung cancer cells in the brain. Applications for second-round projects are now underway.
All projects involve at least one principal investigator from each of the partnering institutions, who jointly advise a doctoral student on a project that could positively impact clinical practice. Participating ENG faculty include Professors Joyce Wong (BME, MSE), Paul Barbone (ME, MSE), Venkatesh Saligrama (ECE, SE) and Yannis Paschalidis (ECE, SE); Associate Professor Porter; and Assistant Professor Roblyer.
“The fields of biomedical imaging and bioengineering have been converging and collaborating for decades, and that collaboration continues to get closer and closer,” said Seltzer, noting a burgeoning clinical need for advanced technologies in functional and molecular imaging; information technologies ranging from data mining to image processing; and minimally-invasive diagnostic and therapeutic procedures guided by high-technology imaging techniques.
Belta to Co-Lead $1 Million Study
By Mark Dwortzan
Traffic congestion is a waste not only of time, but also of energy and money. In 2011, it caused Americans in metropolitan areas to spend 5.5 billion extra hours on the road and pump 2.9 billion extra gallons of fuel into their gas tanks, with associated costs reaching $121 billion—a nearly six-fold increase since 1982. Municipalities have attempted to mitigate traffic congestion through highway onramp metering and fees at peak travel times, but the problem continues to worsen.
Now a research team led by Associate Professor Calin Belta (ME, SE) and University of California, Berkeley Associate Professor Murat Arcak (EECS) is advancing a novel solution that could reduce congestion considerably. Supported by a three-year, $1 million grant from the National Science Foundation, the researchers plan to develop algorithms for a data-driven traffic management software system that optimizes the timing of traffic lights at both highway onramps and roadway intersections in real time.
The work represents a novel application of “formal methods,” a discipline within computer science focused on efficient techniques for proving the correct operation of systems ranging from computer programs to digital circuits, thus ensuring their reliability and robust performance.
“We want to develop a system in which we can guarantee specifications for traffic networks, just as we do for computer programs,” said Belta. “These specifications will include minimizing traffic jams and maximizing the flow of traffic, all while ensuring that pedestrians don’t have to wait a long time to cross the street.”
Whereas current traffic management systems can reduce traffic congestion within small networks of freeways and arterial roads, the formal methods approach promises to do so across much larger networks. In their algorithms, the researchers plan to partition a large road network into small sub-networks, and establish specifications so that enforcing desired traffic patterns in small sub-networks (and on roads linking one sub-network to another) guarantees desired traffic patterns in the original network.
The proposed techniques will be tested in current and upcoming traffic management projects in California sponsored by Caltrans, the state transportation agency. Applications include a prototype decision support system to be deployed along the Interstate 210 corridor north of Los Angeles, and coordinated ramp metering, arterial intersection and variable speed limit management on a freeway in Sacramento and a freeway-arterial interchange in San Jose.
Over the next three years, the team aims to accomplish three main tasks.
“We plan to develop the theory and algorithms to solve the problem, enable the system to accommodate extreme situations such as sporting events and accidents, and apply statistical methods to enhance its performance,” said Belta.
Project Advances Environmentally Friendly Metals Production
By Mark Dwortzan
A team of materials science and engineering graduate students from Professor Uday Pal’s (ME, MSE) research group won the silver medal and an $8,000 cash prize at the TECO Green Tech Contest in Taiwan for their project, “Innovative Green Technology for Cost-Effective Metals Production.” Accompanied by Pal for the final competition in late August, the BU team placed second among 19 teams representing universities from China, Japan, Russia, Singapore and the US.
The purpose of the annual contest is to foster international research collaborations and technical creativity to advance technologies designed to save energy and reduce carbon emissions, from renewable energy production methods to electric vehicles. Teams were judged on creativity, technical content and feasibility, and completeness. The contest was organized by TECO Technology Foundation, Industrial Technology Research Institute and RITEK Foundation.
The BU team (PhD students Shizhao Su, Yihong Jiang and Yiwen Gong, and MEng student Xiao Han) was recognized for demonstrating and modeling solid oxide membrane (SOM) electrolysis, an inexpensive, energy-efficient, environmentally friendly, one-step method that Pal has developed over the past 15 years to separate pure metals from their oxides. SOM electrolysis continuously feeds metal oxide into a molten salt bath, where electricity splits it into metal and oxygen gas in separate chambers.
Conventional metals production technologies employ a lot of carbon-based energy sources to reduce oxides, and generate significant amounts of pollutants, carbon dioxide and other greenhouse gases. SOM electrolysis promises to substantially decrease energy consumption and eliminate carbon and other environmentally harmful emissions associated with reducing oxides to metals, all for less cost. Using this method, the students successfully produced light structural metals (aluminum and magnesium), solar-grade silicon and critical rare earth metals (dysprosium and ytterbium).
”The students employed an innovative inert anode that for the first time enabled oxygen and metal production in separate chambers,” said Pal, who advised the team along with Professor Soumendra Basu (ME, MSE) and Adam C. Powell, IV, CTO of Infinium, a Natick-based company spun off from Pal’s lab that’s working toward scale-up of this technology. “They engineered the process and made it universally applicable for energy-intensive metals production.”
“I was thrilled when ‘Boston University’ was announced as silver medalist,” said Yihong Jiang. “It was a great experience for us to see that we can compete on an international stage with top universities.” Jiang and his teammates will use the cash prize to present and promote their work at future professional society meetings and conferences.
Green Tech Contest teams presented a diverse set of innovative ideas to reduce energy consumption and environmental impact. The contest’s gold medal went to a team from China’s Zhejiang University for its wave-propelled, ocean-monitoring vehicle. Taking bronze was a team from Tsinghua University, also based in China, for its energy-efficient technology to charge electric vehicle batteries. Other entries ranged from personal micro-grid kits to a regenerative braking system for trains.
Can Cells Signal Each Other Via Sound Waves?
Schneider Group Uncovers New Evidence
By Mark Dwortzan
Scientists have long identified two mechanisms for communication between and within cells—immediate contact, in which proteins within or on cell membranes collide; and diffusion, in which a protein on one cell membrane dispatches particles through the cell that eventually impact another protein or make contact with the same or a neighboring cell. Last spring, Assistant Professor Matthias Schneider (ME) produced research results in Physical Review Letters suggesting a third, fundamentally different, potential mechanism that’s far faster and more efficient—acoustic waves.
Realizing that the inner landscape of individual cells is crowded with a network of two-dimensional ridges, known as “interfaces,” that form a distinct, continuous pathway leading from one end of a cell to another or even connecting multiple cells, Schneider and his collaborators created prototypical interfaces out of lipid molecules derived from a cell membrane, and conducted experiments showing that acoustic waves propagated along these interfaces, just as sound travels through air.
Now, in a recent paper in the Journal of the Royal Society publication Interface, Schneider and Research Associate Shamit Shrivastava have determined that under special physical circumstances, these acoustic waves have the same shape, velocity and amplitude as nerve pulses. Moreover, they are only triggered when the stimulus exceeds a critical value, a phenomena known as “all-or-none excitation” in neurophysiology.
“The similarity between our pulses and those measured by Alan Hodgkin and Andrew Huxley—whose model for nerve pulse propagation earned them the 1963 Nobel Prize in Physiology—is overwhelming,” said Schneider. “A few more tests are necessary to make the call, but if we are right, this will completely change the way we think about neurophysiology and cell communication, introducing a new paradigm based on physical principles from thermodynamics and acoustics as predicted by theoretical physicist Konrad Kaufmann in 1989.”
Both studies suggest that proteins in neighboring cells can “communicate” across the continuous 2D interfaces via acoustic waves, potentially enabling biological activities such as energy consumption, digestion and nerve propagation. Representing a major breakthrough in our understanding of how biological systems might communicate, the research could yield important applications ranging from fundamentally new drug targets to novel approaches for treating neurological disease and engineering artificial organs.
BU Team Seeks to Improve Solid Oxide Fuel Cell Lifetimes
Longer Duration Critical to Commercialization
By Mark Dwortzan
The solid oxide fuel cell (SOFC), a device that produces electricity directly from oxidizing a fuel source, is one of the most environmentally benign technologies for converting the chemical energy in fossil fuels to electrical energy. But the performance of today’s SOFCs, which operate at very high temperatures, tends to degrade over time, resulting in shorter lifetimes than those of conventional power generation systems. As SOFC power systems approach commercialization and use in applications ranging from electric power stations to long-haul transportation, their long-term performance is becoming critically important.
At the heart of this problem are the electrochemical interfaces—the cathodes, anodes and electrolytes that enable the fuel cell to work like a turbocharged battery—whose structure changes over time through exposure to high temperatures. To better understand how these interfaces evolve and how their degradation might be mitigated, the Department of Energy has awarded an $800,000 grant to a team of BU researchers with expertise in many areas relevant to the problem, from electrochemistry and coatings to thermodynamics.
The BU team consists of Associate Professor Srikanth Gopalan, Professors Soumendra Basu and Uday Pal, and Assistant Professor Emily Ryan (all ME, MSE); and an industry partner, Fuel Cell Energy of Danbury, Connecticut, one of the world’s leading developers of solid oxide fuel cells.
“This project seeks to unravel the fundamental mechanisms that underlie degradation,” said Gopalan. “Unraveling these complex threads is critical to achieving acceptable lifetimes and broader adoption of SOFCs.”
Engineering the perfect water-repellent surface
By Cynthia K. Buccini, BU Today
Teflon has nothing on the lotus plant; droplets of water that land on the surface of the plant’s leaf roll right off, sweeping away dirt particles as they go.
That extraordinary water repellence is known as superhydrophobicity, and scientists would love to harness it for such things as removing droplets from the surface of airplane wings before they freeze to reduce icing or improving the performance of steam turbines by keeping them dry.
“There are a lot of applications where people really want to get drops not just off surfaces, but off surfaces as fast as possible,” says Assistant Professor James Bird (ME, MSE), who heads ENG’s Interfacial Fluid Dynamics Laboratory.
Bird is studying how to minimize the contact time of a drop on a surface, and while he hasn’t bested nature, he may be coming close.
The lotus leaf and other superhydrophobic surfaces have two things going for them: a liquid-repellent surface chemistry—like a Teflon pan—and a texture that may appear smooth to the naked eye, but is actually roughened by microscopic pits, spikes, and pores. The microscopic texture traps air, so the drop is touching only a fraction of the solid surface.
When a raindrop-sized droplet lands on a superhydrophobic surface, it flattens out like a pancake and then rebounds, leaving the surface 12.4 milliseconds after it arrived.
Bird wanted to figure out how to reduce that contact time. What if the drop retracted in a different way, he wondered. If it splashed unevenly, the drop would theoretically leave the surface faster. “That was our thesis,” he says, “and, spoiler alert—we showed you can do that.”
He and colleagues from MIT found that by changing the surface on which a drop falls, they could change the hydrodynamics of the drop and the contact time. “Our goal was to have something that was manufacturable, more so than just an idea,” Bird says.
They used a laser to etch a rough, microscopic texture onto a silicon wafer, and then added ridges, which were smaller than the droplet, but big enough to see—about the size of a human hair. They captured the bounce using high-speed cameras.
Bird discovered that the drop bounced off the silicon wafer in 7.8 milliseconds, 37 percent faster than off the standard superhydrophobic surface. The explanation: when the drop spreads out into the pancake shape, the thickness varies over the hairlike ridges. That variation leads to variation in retraction speed, which causes the drop to split up and leave the surface more quickly than it would otherwise.
Next, they wanted to learn what would happen if they changed the surface microtexture and the material, from silicon to aluminum and copper. “We see the same dynamics,” says Bird, the lead author on a paper describing the results in the November 21, 2013, issue of Nature.
Finally, they looked to nature for examples of superhydrophobic surfaces similar to the one they created, with both a microscopic texture and the larger ridges. They found those examples in the wings of the Morpho butterfly and the leaves of the nasturtium plant. Bird points to an image, taken by a scanning electron microscope, of the butterfly wing. “You have this roughness,” he says, “making it superhydrophobic, but you also have these veins—and the same for veins on the nasturtium leaf—that cause drops to come off the surface faster. So drops impacting the nasturtium leaf are shed faster than on the lotus leaf.”
Bird thinks the faster bounce rate may be caused by the way the veins are arranged. On the lotus leaf, the veins are just beneath the surface; on the butterfly wing and the nasturtium leaf, they’re on top. “So even though they both have veins that are about the same size, the position of those veins has the effect where one is going to lead to this drop breaking up faster, and the other is not,” he says.
As an engineer, Bird is more comfortable talking about the implications for airplanes and steam turbines than for butterflies and plant leaves. “We’re not doing as well as the butterfly wing,” he says. “But we’re approaching it.”
Klapperich inventing technology that could change future of primary care
By Barbara Moran, BU Today
Biomedical engineer Catherine Klapperich is working on a rapid viral load test for HIV. Photo by Kalman Zabarsky
Catherine Klapperich moves fast, talks fast, and has at least 15 different ideas rolling through her head at the same time. How, for instance, can she keep her postdocs on track, guide 134 undergrads through their senior project, and meanwhile invent new technology that may change medicine as we know it? She arrived a few minutes late for an interview, preoccupied with a more immediate concern: she had accidentally spilled water on her iPhone. She ran down to her lab to stick it into the vacuum oven, hoping that would dry it out. Then she ran back to her office and sat down to talk.
Klapperich holds three associate professorships at BU, in the College of Engineering biomedical engineering and mechanical engineering departments and in the Division of Materials Science and Engineering. She also directs the Center for Future Technologies in Cancer Care. Her lab creates point-of-care diagnostics—tools, like a pregnancy test stick, that doctors and consumers can use to immediately test such conditions as high cholesterol or diagnose illnesses like strep throat. One critical need in the developing world is a rapid test for HIV viral load—the amount of HIV in a patient’s blood. The number helps doctors monitor the disease, decide when to start treatment, and determine if HIV medications are working.
BU Today recently spoke to Klapperich about her work.
BU Today: A lot of your work focuses on public health issues. Where does that interest come from?
Klapperich: When I got my PhD at Berkeley, I was studying artificial hips and knees. They have a metal part and a plastic part, and we were engineering the plastic part. I became interested in how cells interact with biomaterial surfaces. And that led into my postdoc, which focused on how cells interact with biomaterials at the level of gene expression.
At that time, gene chips were just becoming a routine tool in the laboratory. And I was completely floored by all the steps to use them: breaking the cells open, getting the DNA or RNA out, amplifying it, putting it on a chip, and then turning on the reader to figure out the expression levels. It was a huge number of steps. As an engineer I thought, why? So I became really interested in doing this stuff in a turn-crank way, where I wouldn’t have to do all the little steps.
A machine would do it instead?
The machine would do it. The gene chip is a wondrous thing. And yet it took two and a half days to make the material to go onto that chip. So I became very focused on the sample preparation process. Then it became clear to me that this is why point-of-care diagnostics do not exist in the numbers that they should. Because yeah, we have this chip and it can tell us all this information, but all this prep requires someone with a lot of laboratory skill.
So you want to take the diagnostic chip, have some patient spit on it, and then have the answer show up without two and a half days of sample prep?
Right. And so for DNA and RNA it’s hard, because most of it is inside of our cells or inside the bugs that infect us. So you have to break cells apart and amplify the DNA or RNA—make many, many copies. Then you tag them with something like a fluorescent protein that allows you to see them. So we need to do three things: we need to extract, we need to amplify, we need to read. Let’s do those three things as simply as we can, in as few steps as we can, as reliably as we can. We want to be the test kitchen for this work.
This field has grown a lot, even in the last 10 years.
Yeah—now you can walk into Walgreens and there’s a little blue sign hanging over the aisle, where it says things like Foot Powder and Toothpaste, and it says Diagnostics. And I remember the first time I saw that a few years ago. I thought, what? That’s crazy! This is now a thing in the aisle.
It’s a noun.
Exactly. There are the glucose strips, there’s a cholesterol test. You can buy a drug test—
A drug test for what?
For your kid. This is the marijuana one.
Really? This box you’re showing me is a marijuana test kit?
Yeah. This is great. You can buy the 4-drug test, the 7-drug test, or the 12-drug test. You can test your kid for depressants, barbiturates, methadone, benzodiazepines, opiates, ecstasy, amphetamines, methamphetamines, cocaine, marijuana, and Oxy. It’s pretty amazing. And it’s just pee. I think it really empowers people to have information about their own health. If you think about cholesterol tests, and HIV yes/no, respiratory infections, strep, these things can be done by the patient. That can save an office visit, which saves money; it saves the potential of infecting other people; it saves the time of the clinician. I think it will change the primary care model a lot.
What’s the first thing out of your lab that might make it into Walgreens?
It’s an HIV viral load test that we’re working on with a company in San Francisco. A colleague told me last week, from his clinic in South Africa, “We need a viral load test. If people come to see me and I tell them, ‘I’m going to take your blood, come back to get the results,’ 50 percent of them just don’t come back. Something that would help tomorrow is if I could give that person their results right there. And if their viral load is suppressed, then I don’t have to expend any resources seeing that person until the following year.”
They’re testing that right now in South Africa. That could be deployed in a primary care clinician’s office, and that’s the first thing that will come from our laboratory.
That will be cool.
Yeah, it will be very cool.