Awakening of the zygote genome over time as decreasing individual cell size triggers early embryo transcription. (Image: Hui Chen, Penn Medicine; Cell Press)
There is a transition during early development when an embryo undergoes biochemical changes, switching from being controlled by maternal molecules to being governed by its own genome.
For the first time, a team from the Perelman School of Medicine found in an embryo that activation of its genome does not happen all at once, instead it follows a specific pattern controlled primarily by the various sizes of its cells. The researchers published their results as the cover story in Developmental Cell.
In an early embryo undergoing cell division, maternally loaded RNA and proteins regulate the cell cycle. The genomes of the zygote—a term for the fertilized egg—are initially in sleep mode. However, at a point in the early life of the embryo, these zygotic nuclei “wake up” and expression from their genomes takes biochemical control over subsequent embryo development. But how an embryo “recognizes” when to undergo this transition has remained unknown.
“How an embryo ‘hands over’ control of development from mother to zygote is a fundamental question in developmental biology,” says senior author Matthew C. Good, an assistant professor of both cell and developmental biology and bioengineering. “Previously it was not appreciated that different regions of a vertebrate embryo can undergo genome activation at different times, or how directly cell size regulates the awakening of a zygote’s genome.”
New 3D Tumor Models Could Improve Cancer Treatment
New ways of testing cancer treatments may now be possible thanks to researchers at the University of Akron who developed three-dimensional tumor models of triple-negative breast cancer. Led by Dr. Hossein Tavana, Ph. D., an associate professor of biomedical engineering at the university, the Tissue Engineering Microtechnologies Lab recently received a $1.13 million grant from the prestigious National Cancer Institute (NCI) of the National Institute of Health (NIH) to continue improving these tumor models. Tumors are difficult to fully replicate in vitro, as they are comprised of cancerous cells, connective tissue, and matrix proteins, among several other components. With this new grant, Tavana sees creating a high-throughput system that uses many identical copies of the tumor model for drug testing and better understanding of the way tumors operate. This high-throughput method would allow Tavana and his lab to isolate and test several different approaches at once, which they hope will help change the way tumors are studied and treated everywhere.
Noise-Induced Hearing Loss Poses Greater Threat to Neural Processing
Even though we all know we probably shouldn’t listen to music at high volumes, most of us typically do it anyway. But researchers at Purdue University recently found that noise-induced hearing loss could cause significant changes in neural processing of more complex sound inputs. Led by Kenneth Henry, Ph.D., an assistant professor of otolaryngology at the University of Rochester Medical Center, and Michael Heinz, Ph.D., a professor of biomedical engineering at Purdue University, the study shows that when compared with age-related hearing loss, noise-induced hearing loss will result in a greater decrease in hearing perception even when the two kinds of hearing loss appear to be of the same degree on an audiogram. This is because noise-induced hearing loss occurs because of physical trauma to the ear, rather than the long-term electrochemical degradation of some components that come happen with age. The evidence of this research is yet another reason why we should be more careful about exposing our ears to louder volumes, as they pose a greater risk of serious damage.
Increasing the Patient Populations for Research in Cartilage Therapy and Regenration
Despite the great progress in research of knee cartilage therapy and regeneration, there are still issues with the patient populations that most studies consider. Researchers often want to test new methods on patients that have the greatest chance of injury recovery without complications – often referred to as “green knees” – but this leaves out those patient populations who suffer from conditions or defects that have the potential to cause complications – often referred to as “red knees.” In a new paper published in Regenerative Medicine, the Mary Black Ralston Professor for Education and Research in Orthopaedic Surgery and secondary faculty in the Department of Bioengineering at Penn, Robert Mauck, Ph.D., discusses some cartilage therapies that may be suitable for red knee populations.
Working with James Carey, M.D., the Director of the Penn Center for Cartilage Repair and Osteochondritis, Mauck and his research team realized that even those with common knee cartilage conditions such as the presence of lesions or osteoarthritis were liable to be excluded from most regeneration studies. In discussing alternatives methods and structures of studying cartilage repair and regeneration, Mauck and Carey hope that future therapies will be applicable to a wider range of patient populations, and that there will soon be more options beyond full joint replacement for those with red knee conditions.
Plant-Like Superhydrophobicity Has Applications in Biomedical Engineering
Researchers in the Department of Biomedical Engineering at Texas A&M University recently found ways of incorporating the superhydrophobic properties of some plant leaves into biomedical applications through what they’re calling a “lotus effect.” The Gaharwar Lab, led by principal investigator and assistant professor of biomedical engineering Akhilesh Gaharwar, Ph.D., developed an assembly of two-dimensional atomic layers that they describe as a “nanoflower” to help control surface wetting in a biomedical setting. A recent paper published in Chemical Communications describes Gaharwar and his team’s work as expanding the use of superhydrophobic surface properties in biomedical devices by demonstrating the important role that atomic vacancies play in the wetting characteristic. While Gaharwar hopes to research the impact that controlling superhydrophobicity could have in stem cell applications, his work already allows for innovations in self-cleaning and surface properties of devices involving labs-on-a-chip and biosensing.
People and Places
Nader Engheta, H. Nedwill Ramsey Professor in Electrical and Systems Engineering, Bioengineering and Materials Science and Engineering, has been inducted into the Canadian Academy of Engineering (CAE) as an International Fellow. The CAE comprises many of Canada’s most accomplished engineers and Engheta was among the five international fellows that were inducted this year.
The Academy’s President Eddy Isaacs remarked: “Over our past 32 years, Fellows of Academy have provided insights in the fields of education, infrastructure, and innovation, and we are expecting the new Fellows to expand upon these contributions to public policy considerably.”
We would like to congratulate Anthony Lowman, Ph.D., on his appointment as the Provost and Senior Vice President for Academic Affairs at Rowan University. Formerly the Dean of Rowan’s College of Engineering, Lowman helped the college double in size, and helped foster a stronger research community. Lowman also helped to launch a Ph.D. program for the school, and added two new departments of Biomedical Engineering and Experiential Engineering Education in his tenure as the dean. Widely recognized for his research on hydrogels and drug delivery, Lowman was also formerly a professor of bioengineering at Temple University and Drexel University.
Lastly, we would like to congratulate Daniel Lemons, Ph.D., on his appointment as the Interim President of Lehman College of the City University of New York. Lemons, a professor in the Department of Biology at City College, specializes in cardiovascular and comparative physiology, and was also one of the original faculty members of the New York Center for Biomedical Engineering. With prior research funded by both the National Institute of Health (NIH) and the National Science Foundation (NSF), Lemons also holds patents in biomechanics teaching models and mechanical heart simulators.
DNA Microscopy Gives a Better Look at Cell and Tissue Organization
A new technique that researchers from the Broad Institute of MIT and Harvard University are calling DNA microscopy could help map cells for better understanding of genetic and molecular complexities. Joshua Weinstein, Ph.D., a postdoctoral associate at the Broad Institute, who is also an alumnus of Penn’s Physics and Biophysics department and former student in Penn Bioengineering Professor Ravi Radhakrishnan’s lab, is the first author of this paper on optics-free imaging published in Cell.
The primary goal of the study was to find a way of improving analysis of the spatial organization of cells and tissues in terms of their molecules like DNA and RNA. The DNA microscopy method that Weinstein and his team designed involves first tagging DNA, and allowing the DNA to replicate with those tags, which eventually creates a cloud of sorts that diffuses throughout the cell. The DNA tags subsequent interactions with molecules throughout the cell allowed Weinstein and his team to calculate the locations of those molecules within the cell using basic lab equipment. While the researchers on this project focused their application of DNA microscopy on tracking human cancer cells through RNA tags, this new method opens the door to future study of any condition in which the organization of cells is important.
If you’ve ever pressed a picture-hanging strip onto the wall only to realize it’s slightly off-center, you know the disappointment behind adhesion as we typically experience it: it may be strong, but it’s mostly irreversible. While you can un-stick the used strip from the wall, you can’t turn its stickiness back on to adjust its placement; you have to start over with a new strip or tolerate your mistake. Beyond its relevance to interior decorating, durable, reversible adhesion could allow for reusable envelopes, gravity-defying boots, and more heavy-duty industrial applications like car assembly.
Such adhesion has eluded scientists for years but is naturally found in snail slime. A snail’s epiphragm — a slimy layer of moisture that can harden to protect its body from dryness — allows the snail to cement itself in place for long periods of time, making it the ultimate model in adhesion that can be switched on and off as needed. In a new study, Penn Engineers demonstrate a strong, reversible adhesive that uses the same mechanisms that snails do.
Low-Dose Radiation CT Scans Could Be Improved by Machine Learning
Machine learning is a type of artificial intelligence growing more and more popular for applications in bioengineering and therapeutics. Based on learning from patterns in a way similar to the way we do as humans, machine learning is the study of statistical models that can perform specific tasks without explicit instructions. Now, researchers at Rensselaer Polytechnic Institute (RPI) want to use these kinds of models in computerized tomography (CT) scanning by lowering radiation dosage and improving imaging techniques.
A recent paper published in Nature Machine Intelligence details the use of modularized neural networks in low-dose CT scans by RPI bioengineering faculty member Ge Wang, Ph.D., and his lab. Since decreasing the amount of radiation used in a scan will also decrease the quality of the final image, Wang and his team focused on a more optimized approach of image reconstruction with machine learning, so that as little data as possible would be altered or lost in the reconstruction. When tested on CT scans from Massachusetts General Hospital and compared to current image reconstruction methods for the scans, Wang and his team’s method performed just as well if not better than scans performed without the use of machine learning, giving promise to future improvements in low-dose CT scans.
A Mind-Controlled Robotic Arm That Requires No Implants
A new mind-controlled robotic arm designed by researchers at Carnegie Mellon University is the first successful noninvasive brain-computer interface (BCI) of its kind. While BCIs have been around for a while now, this new design from the lab of Bin He, Ph.D., a Trustee Professor and the Department Head of Biomedical Engineering at CMU, hopes to eliminate the brain implant that most interfaces currently use. The key to doing this isn’t in trying to replace the implants with noninvasive sensors, but in improving noisy EEG signals through machine learning, neural decoding, and neural imaging. Paired with increased user engagement and training for the new device, He and his team demonstrated that their design enhanced continuous tracking of a target on a computer screen by 500% when compared to typical noninvasive BCIs. He and his team hope that their innovation will help make BCIs more accessible to the patients that need them by reducing the cost and risk of a surgical implant while also improving interface performance.
KIChE is an organization that aims “to promote constructive and mutually beneficial interactions among Korean Chemical Engineers in the U.S. and facilitate international collaboration between engineers in U.S. and Korea.”
We would also like to congratulate Natalia Trayanova, Ph.D., of the Department of Biomedical Engineering at Johns Hopkins University on being inducted into the Women in Tech International (WITI) Hall of Fame. Beginning in 1996, the Hall of Fame recognizes significant contributions to science and technology from women. Trayanova’s research specializes in computational cardiology with a focus on virtual heart models for the study of individualized heart irregularities in patients. Her research helps to improve treatment plans for patients with cardiac problems by creating virtual simulations that help reduce uncertainty in either diagnosis or courses of therapy.
Finally, we would like to congratulate Andre Churchwell, M.D., on being named Vanderbilt University’s Chief Diversity Officer and Interim Vice Chancellor for Equity, Diversity, and Inclusion. Churchwell is also a professor of medicine, biomedical engineering, and radiology and radiological sciences at Vanderbilt, with a long career focused in cardiology.
Every cell in your body has a copy of your genome, tightly coiled and packed into its nucleus. Since every copy is effectively identical, the difference between cell types and their biological functions comes down to which, how and when the individual genes in the genome are expressed, or translated into proteins.
Scientists are increasingly understanding the role that genome folding plays in this process. The way in which that linear sequence of genes are packed into the nucleus determines which genes come into physical contact with each other, which in turn influences gene expression.
LADL combines CRISPR/Cas9 and optogenetics to bring two distant points in a linear gene sequence into physical contact, forming a folding pattern known as a “loop.” Looping interactions influence gene expression, so the researchers envision LADL as being a powerful tool for studying these dynamics.
Jennifer Phillips-Cremins, assistant professor in Penn Engineering’s Department of Bioengineering, is a pioneer in this field, known as “3-D Epigenetics.” She and her colleagues have now demonstrated a new technique for quickly creating specific folding patterns on demand, using light as a trigger.
The technique, known as LADL or light-activated dynamic looping, combines aspects of two other powerful biotechnological tools: CRISPR/Cas9 and optogenetics. By using the former to target the ends of a specific genome fold, or loop, and then using the latter to snap the ends together like a magnet, the researchers can temporarily create loops between exact genomic segments in a matter of hours.
The ability to make these genome folds, and undo them, on such a short timeframe makes LADL a promising tool for studying 3D-epigenetic mechanisms in more detail. With previous research from the Phillips-Cremins lab implicating these mechanisms in a variety of neurodevelopmental diseases, they hope LADL will eventually play a role in future studies, or even treatments.
Jennifer Phillips-Cremins, Ji Hun Kim and Mayuri Rege
Alongside Phillips-Cremins, lab members Ji Hun Kim and Mayuri Rege led the study, and Jacqueline Valeri, Aryeh Metzger, Katelyn R. Titus, Thomas G. Gilgenast, Wanfeng Gong and Jonathan A. Beagan contributed to it. They collaborated with associate professor of Bioengineering Arjun Raj and Margaret C. Dunagin, a member of his lab.
“In recent years,” Phillips-Cremins says, “scientists in our fields have overcome technical and experimental challenges in order to create ultra-high resolution maps of how the DNA folds into intricate 3D patterns within the nucleus. Although we are now capable of visualizing the topological structures, such as loops, there is a critical gap in knowledge in how genome structure configurations contribute to genome function.”
In order to conduct experiments on these relationships, researchers studying these 3D patterns were in need of tools that could manipulate specific loops on command. Beyond the intrinsic physical challenges — putting two distant parts of the linear genome in physical contact is quite literally like threading a needle with a thread that is only a few atoms thick — such a technique would need to be rapid, reversible and work on the target regions with a minimum of disturbance to neighboring sequences.
The advent of CRISPR/Cas9 solved the targeting problem. A modification of the gene editing tool allowed researchers to home in on the desired sequences of DNA on either end of the loop they wanted to form. If those sequences could be engineered to seek one another out and snap together under the other necessary conditions, the loop could be formed on demand.
Cremins Lab members then sought out biological mechanisms that could bind the ends of the loops together, and found an ideal one in the toolkit of optogenetics. The proteins CIB1 and CRY2, found in Arabidopsis, a flowering plant that’s a common model organism for geneticists, are known to bind together when exposed to blue light.
“Once we turn the light on, these mechanisms begin working in a matter of milliseconds and make loops within four hours,” says Rege. “And when we turn the light off, the proteins disassociate, meaning that we expect the loop to fall apart.”
“There are tens of thousands of DNA loops formed in a cell,” Kim says. “Some are formed slowly, but many are fast, occurring within the span of a second. If we want to study those faster looping mechanisms, we need tools that can act on a comparable time scales.”
As shown in a 2013 Nature Methods paper by fellow Penn bioengineer Lukasz Bugaj, the optical response of the CRY2 protein is a key component of LADL. When the blue light is turned on, CRY2 proteins in cell immediately find one another and bind together into clumps large enough to be seen under magnification. When the light is turned off, the clumps begin to dissolve away.”
Fast acting folding mechanisms also have an advantage in that they lead to fewer perturbations of the surrounding genome, reducing the potential for unintended effects that would add noise to an experiment’s results.
The researchers tested LADL’s ability to create the desired loops using their high-definition 3D genome mapping techniques. With the help of Arjun Raj, an expert in measuring the activity of transcriptional RNA sequences, they also were able to demonstrate that the newly created loops were impacting gene expression.
The promise of the field of 3D-epigenetics is in investigating the relationships between these long-range loops and mechanisms that determine the timing and quantity of the proteins they code for. Being able to engineer those loops means researchers will be able to mimic those mechanisms in experimental conditions, making LADL a critical tool for studying the role of genome folding on a variety of diseases and disorders.
“It is critical to understand the genome structure-function relationship on short timescales because the spatiotemporal regulation of gene expression is essential to faithful human development and because the mis-expression of genes often goes wrong in human disease,” Phillips-Cremins says. “The engineering of genome topology with light opens up new possibilities to understanding the cause-and-effect of this relationship. Moreover we anticipate that, over the long term, the use of light will allow us to target specific human tissues and even to control looping in specific neuron subtypes in the brain.”
The research was supported by the New York Stem Cell Foundation; Alfred P. Sloan Foundation; the National Institutes of Health through its Director’s New Innovator Award from the National Institute of Mental Health, grant no. 1DP2MH11024701, and a 4D Nucleome Common Fund, grant no. 1U01HL1299980; and the National Science Foundation through a joint NSF-National Institute of General Medical Sciences grant to support research at the interface of the biological and mathematical sciences, grant no. 1562665, and a Graduate Research Fellowship, grant no. DGE-1321851.
Innovations in Vascularization Could Lead to a New Future in Bioprinting
We may be one step closer to 3D-printing organs for transplants thanks to innovations in vascularization from researchers at Rice University and Washington University. Jordan Miller, Ph.D., a Penn Bioengineering alumnus, now an assistant professor of bioengineering at Rice, worked with his colleague Kelly Stevens, Ph.D., an assistant professor of the bioengineering department at Washington, to develop 3D-printed networks that mimicked the vascularized pathways for the transport of blood, lymph, and other fluids in the body. Their work appeared on a recent cover of Science, featuring a visual representation of the 3D-printed vessels in vasculature meant to mirror that of the human lung.
Relying heavily on open source 3D-printing, Miller and Stevens, along with collaborators from a handful of other institutions and start-ups, found ways to model dynamic vasculature systems similar to heart valves, airways systems, and bile ducts to keep 3D-printed tissue viable. The video below demonstrates the way the team successfully modeled vasculature in a small portion of the lung by designing a net-like structure around a sack of air. But Miller, a long-time supporter of open source printing and bioprinting, hopes that this is merely one step closer to what he sees as the ultimate goal of allowing for all organs to be bioprinted. Having that sort of power would reduce the complex issues that come with organ transplants, from organ availability to compatibility, and bring an end to a health issue that affects the over 100,000 people on the organ transplant waiting list.
A Combination of Protein Synthesis and Spectrometry Improve Cell Engineering
One goal of modern medicine is to create individualized therapeutics by figuring out a way to control cell function to perform specific tasks for the body without disrupting normal cell function. Balancing these two goals often proves to be one of the greatest difficulties of this endeavor in the lab, but researchers at Northwestern University found a way to combine the two functions at once in methods they’re calling cell-free protein synthesis and self-assembled monolayer desorption ionization (SAMDI) mass spectrometry. This innovation in the combination of the two methods accelerates the trial and error process that comes with engineering cells for a specific need, allowing researchers to cover a lot more ground in determining what works best in a smaller amount of time.
Leading the study are Milan Mrksich, Ph.D., a Henry Wade Rogers Professor of Biomedical Engineering at Northwestern, and Michael Jewett, Ph.D., a Charles Deering McCormick Professor of Teaching Excellence and co-director of the Center for Synthetic Biology at Northwestern. Together, they hope to continue to take advantage of the factory-like qualities of cell operations in order to use cells from any organisms to our advantage as needed. By helping to reduce the amount of time spent on trial and error, this study brings us one step closer to a world of efficient and individualized medicine.
Non-Invasive Sensory Stimulation as New Way of Treating Alzheimer’s
What if we could reduce the effects of Alzheimer’s disease with a non-invasive therapy comprised of only sensory inputs of light and sound? A recent study between Georgia Tech and MIT tries to make that possible. Alzheimer’s patients often have a larger than normal number of amyloid plaques in their brains, which is a naturally occurring protein that in excess can disrupt neurological function. The treatment — designed in part by Abigail Paulson, a graduate student in the lab of Annabelle Singer, Ph.D., assistant professor of Biomedical Engineering at Georgia Tech and Emory University — uses a combination of light and sound to induce gamma oscillations in brain waves of mice with high amounts of these amyloid plaques. Another lead author of the study is Anthony Martorell, a graduate student in the Tsai Lab at MIT, where Singer was a postdoctoral researcher.
This new approach is different from other non-invasive brain therapies for memory improvement, as tests demonstrated that it had the power to not only reach the visual cortex, but that it also had an effect on the memory centers in the hippocampus. An innovation like this could bring about a more widespread form of treatment for Alzheimer’s patients, as the lack of a need for surgery makes it far more accessible. Singer hopes to continue the project in the future by looking at how these sensory stimulations affect the brain throughout a variety of processes, and more importantly, if the therapy can be successfully applied to human patients.
NIH Grant Awarded to Marquette Biomedical Engineering Professor for Metal Artifact Reduction Techniques in CT Scans
Taly Gilat-Shmidt, Ph.D., an associate professor of biomedical engineering at Marquette University, recently received a $1.4 million grant from the National Institute of Health to improve methods for radiation treatment through metal artifact reduction techniques. When patients have some sort of metal that can’t be removed, such as an orthopaedic implant like a hip or knee replacement, it can interfere with the imaging process for CT scans and lead to inaccuracies by obscuring some tissue in the final images. These inaccuracies can lead to difficulty in devising treatment plans for patients who require radiation, as CT scans are often used to assess patients and determine which line of treatment is most appropriate. Gilat-Schmidt hopes to use the grant to implement tested algorithms to help reduce this variability in imaging that comes from metal implants.
People and Places
Activities for Community Education in Science (ACES), founded by Penn chemistry graduate students in 2014, aims to inspire interest and provide a positive outlook in STEM for kids and their families. The biannual event provides students grades 3–8 with an afternoon of demonstrations, experiments, and hands-on activities focused on physics and chemistry.
After an explosive opening demonstration, more than 70 students made their way between experiments in small groups, each participating in different experiments based on their age.
The Society of Women Engineers (SWE) is a non-profit organization serving as one of the world’s largest advocates for women in engineering and technology over the past six decades. With a mission to empower women to become the next leading engineers of the world, SWE is just one of many agents hoping to bring more diversity to the field. Our chapter of SWE at Penn focuses particularly on professional development, local educational outreach, and social activities across all general body members. In a new article from SWE Magazine, the organization collected social media responses from the public on the women engineers we should all know. With a diverse list of engineers from both the past and present, the article helps bring to light just how much even a handful of women contributed to the field of engineering already.
Bio-inspiration Informs New Football Helmet Design from IUPUI Students
Art, design, biology, and engineering all interact with each other in a recent design for a football helmet from two students— one of media arts and the other of engineering — at the Indiana University – Purdue University Indianapolis. Directed by Lecturer in Media Arts and Science Zebulun Wood, M.S., and Associate Professor of Mechanical and Energy Engineering and Assistant Professor of Biomedical Engineering Andres Tovar, Ph.D., the students found inspiration in biological structures like a pomelo peel, nautilus shell, and woodpecker skull to create energy-absorbing helmet liners. The resulting design took these natural concussion-reducing structures and created compliant mechanism lattice-based liners the replace the foam traditionally placed in between two harder shells of a typical helmet. Their work not only exemplifies the benefits of bio-inspiration, but demonstrates the way that several different domains of study can overlap in the innovation of a new product.
Study of Mechanical Properties of Hyaluronic Acid Could Help Inform Current Debates Over Treatment Regulation for Osteoarthritis
Arthritis is an extremely common condition, especially in older patients, in which inflammation of the joints can cause high amounts of stiffness and pain. Osteoarthritis in particular is the result of the degradation of flexible tissue between the bones of a joint, which increases friction in joint motion. A common treatment of this form of arthritis is the injection of hyaluronic acid, which is meant to provide joint lubrication, and decreases this friction between bones. Recently, however, there has been a debate over hyaluronic acid’s classification by the FDA and whether it should remain based on the knowledge of the mechanical actions of the acid in treatment for osteoarthritis or if potential chemical action of the acid should be considered as well.
Because of limited ways of testing the mechanical properties of the acid, many researchers felt that there could be more to hyaluronic acid’s role in pain relief for arthritic patients. But Lawrence Bonassar, Ph.D., the Daljit S. and Elaine Sarkaria Professor in Biomedical Engineering at the Meinig School of Bioengineering of Cornell University, had another idea. With his lab, he created a custom-made tribometer to measure the coefficient of friction of a given lubricant by rubbing a piece of cartilage back and forth across a smooth glass plate. The research demonstrated that hyaluronic acid’s ability to reduce the coefficient of friction aligned with patients’ pain relief. Bonassar and his team hope that these results will demonstrate the heavy contribution of mechanical action that hyaluronic acid has in osteoarthritis treatment, and help bring an end to the debate over its FDA classification.
A New Way of Mapping the Heart Could Lead to Better Understanding of Contractile Activity
Though reduced contractions in certain regions of the heart can be an indicator of a certain condition, there is currently no way to directly measure contractile activity. This is why Cristian Linte, Ph.D., an Associate Professor of Biomedical Engineering in the Kate Gleason College of Engineering at the Rochester Institute of Technology (RIT), hopes to create a map of the heart that can quantify contraction power. In collaboration with Niels Otani, Ph.D., an Associate Professor in the School of Mathematics at RIT, Linte plans to use an $850,000 grant from the National Science Foundation to achieve a more comprehensive understanding of the heart through both medical imaging and mechanical modeling. The group hopes that their approach will lead to not only a better way to diagnose certain heart conditions and diseases, but also open up understanding of active contraction, passive motion, and the stresses within the heart walls that underlie each.
Celebrity Cat Lil Bub Helps Penn and German Researchers Draw Public Attention to Genetics
Lil Bub’s unique appearance has garnered millions of online fans, and now, an avenue for researchers to talk about genetics. (Photo Courtesy of Mike Bridavsky)
In 2015, a group of curious researchers set out to sequence the genome of a celebrity cat named Lil Bub. They were hoping to understand the genetics behind Lil Bub’s extra toes and unique skeletal structure, which contribute to her heart-warming, kitten-like appearance. However, an equally important goal of their “LilBUBome” project was to invite the general public into the world of genetics.
Because of Lil Bub’s online fame, the project garnered attention from her fans and the media, all hoping to discover the secret to Lil Bub’s charm. As early as 2015, Gizmodo’s Kiona Smith-Strickland reported on the team’s intentions to sequence Lil Bub’s genome, and, since then, many have been awaiting the results of the LilBUBome.
The Alfred P. Sloan Foundation awarded a six-year grant to Barnard College and Columbia University’s School of Engineering and Applied Science to support graduate education for women in engineering. The funding will go towards a new five-year program that enables Barnard students to attain both a B.A. and M.S. in one year after their traditional four years of undergraduate education. The program will offer M.S. degrees in chemical engineering, biomedical engineering, and industrial engineering and operations research, and is one of the first of its kind for women’s colleges.
We would like to congratulate Jean Paul Allain, Ph.D., on being named the first head of the new Ken and Mary Alice Lindquist Department of Nuclear Engineering at Penn State. Allain, who is currently a Professor and head of graduate programs in the University of Illinois at Urbana-Champaign’s Department of Nuclear, Plasma, and Radiological Engineering, conducts research in models of particle-surface interactions. In addition to being head of the new department at Penn State, Allain will also hold a position as a Professor of Biomedical Engineering at the university.
We would also like to congratulate Andrew Douglas, Ph.D., on his appointment as the Vice Provost for Faculty Affairs at Johns Hopkins University. Douglas currently holds the position of Vice Dean for Faculty at the Whiting School of Engineering, and has joint appointments in Mechanical and Biomedical Engineering. Douglas’s research at Hopkins focuses on mechanical properties and responses of compliant biological tissue and on the nonlinear mechanics of solids, with a focus on soft tissues and organs like the heart and tongue.
Dan Huh, the Wilf Family Term Assistant Professor in the Department of Bioengineering, focuses his research on creating organs-on-chips: specially manufactured micro-devices with human cells that mimic the natural cellular processes of organs. Huh’s lab has engineered chips that approximate the functioning of placentas and lung disease, some of which were launched into space in May. Most recently, Huh published a review of organ-on-a-chip technology in the journal Science with graduate students Sunghee Estelle Park and Andrei Georgescu.
The June 2019 issue of Science is a special issue centered around the science of growing human organ models in the laboratory. Such in vitro organs are known as organoids; they grow and develop much like organs do in the body, as opposed to Huh’s organs-on-chips, in which cells from the relevant organs are grown within a fabricated device that imitates some of the organ’s functions and natural environment.
In a video accompanying the review article, Huh explains how organoid and organ-on-a-chip technologies differ and the advantages that accompany each approach:
Unlike Organ-on-a-Chip, which are heavily engineered man-made systems, organoids allow us to mimic the complex of the human body in a more natural way. So organoids represent a more realistic model, but they have problems because they develop in a highly variable fashion and it’s not very easy to control their environment. So we think that Organ-on-a-Chip Technology is a promising solution to many of these problems.
Read Huh, Park, and Georgescu’s review article at Science.
On May 8, 2019, first year Bioengineering students at the University of Pennsylvania gathered together for a marathon two-hour session in which no fewer than twenty-one groups presented the results of their final projects. These projects were the culmination of two semesters’ work in the courses BE 100 and 101, the department’s year-long introduction to Bioengineering. The topics were as diverse and creative as the students, ranging from medical devices and pediatric monitors to plant-care and diagnostic apps. They covered a variety of issues and needs, including tools to help the blind; lockboxes that incorporate breathalyzers (to stop you getting to your keys when intoxicated); mechanisms to sense epileptic seizures and monitor heart rate; and more. Each group had only four minutes to present the research, concept, and results of their project and give a brief demonstration. In the end, the entire class voted and two clear winners emerged. In first place was Group R7 with Heart Guide, a heart-shaped ultrasonic collision device for the blind. Group R3 came in second place with Pulsar the Robot, an adorable pediatric heart rate monitor. The course’s instructor, Dr. Michael Rizk, ended by saying that all of the students should be very proud of their work and that these final projects and the skills learned in year one are the foundation on which the rest of their BE curriculum will be based.
Congratulations to all of our first years on their amazing work. Check out some photos of their impressive work below! For more information on the Penn Bioengineering Undergraduate Curriculum, visit the department website. Most BE student projects are created in the George H. Stephenson Foundation Education Laboratory and “Bio-MakerSpace”, the department’s primary teaching lab.
Vector Flow Imaging Helps Visualize Blood Flow in Pediatric Hearts
A group of biomedical engineers at the University of Arkansas used a new ultrasound-based imaging technique called vector flow imaging to help improve the diagnosis of congenital heart disease in pediatric patients. The study, led by associate professor of biomedical engineering Morten Jensen, Ph.D., collaborated with cardiologists at the local Children’s Hospital in Little Rock to produce images of the heart in infants to help potentially diagnose congenital heart defects. Though the use of vector flow imaging has yet to be developed for adult patients, this type of imaging could possibly provide more detail about the direction of blood flow through the heart than traditional techniques like echocardiography do. In the future, the use of both techniques could provide information about both the causes and larger effects of heart defects in patients.
Using Stem Cells to Improve Fertility in Leukemia Survivors
One of the more common side effects of leukemia treatment in female patients is infertility, but researchers at the University of Michigan want to change that. Led by associate professor of biomedical engineering Ariella Shikanov, Ph.D., researchers in her lab found ways of increasing ovarian follicle productivity in mice, which directly relates to the development of mature eggs. The project involves the use of adipose-derived stem cells, that can be found in human fat tissue, to surround the follicles in an ovary-like, three-dimensional scaffold. Because the radiation treatments for leukemia and some other cancers are harmful to follicles, increasing their survival rate with this stem cell method could reduce the rate of infertility in patients undergoing these treatments. Furthermore, this new approach is innovative in its use of a three-dimensional scaffold as opposed to a two-dimensional one, as it stimulates follicle growth in all directions and thus helps to increase the follicle survival rate.
Penn Engineers Look at How Stretching & Alignment of Collagen Fibers Help Cancer Cells Spread
Cancer has such a massive impact on people’s lives that it might be easy to forget that the disease originates at the cellular level. To spread and cause significant damage, individual cancer cells must navigate the fibrous extracellular environment that cells live in, an environment that Penn Engineer Vivek Shenoy has been investigating for years.
Shenoy’s most recent study on cancer’s mechanical environment was led by a postdoctoral researcher in his lab, Ehsan Ban. Paul Janmey, professor in Physiology and Bioengineering, and colleagues at Stanford University also contributed to the study. Shenoy also received the Heilmeier Award this March and delivered the Heilmeier Award Lecture in April.
Controlled Electrical Stimulation Can Prevent Joint Replacement Infections
Joint replacements are one of the most common kinds of surgery today, but they still require intense post-operative therapy and have a risk of infection from the replacement implant. These infections are usually due to the inflammatory response that the body has to any foreign object, and can become serious and life-threatening if left untreated. Researchers at the University of Buffalo Jacobs School of Medicine and Biomedical Sciences hope to offer a solution to preventing infections through the use of controlled electrical stimulation. Led by Mark Ehrensberger, Ph.D., Kenneth A. Krackow, M.D., and Anthony A. Campagnari, Ph.D., the treatment system uses the electrical signal to create an antibacterial environment at the interface of the body and the implant. While the signal does not prevent infections completely, these antibacterial properties will prevent infections from worsening to a more serious level. Patented as the Biofilm Disruption Device TM, the final product uses two electrode skin patches and a minimally invasive probe that delivers the electrical signal directly to the joint-body interface. The researchers behind the design hope that it can help create a more standard way of effectively treating joint replacement infections.
People and Places
TBx: Gabriel Koo, Ethan Zhao, Daphne Cheung, and Shelly Teng
For their senior design project, four bioengineering seniors — Gabriel Koo, Ethan Zhao, Daphne Cheung, and Shelly Teng — created a low-cost tuberculosis diagnostic that they called TBx. Using their knowledge of the photoacoustic effect of certain dyes, the platform the group created can detect the presence of lipoarabinomannan in patient urine. The four seniors presented TBx at the Rice360 Design Competition in Houston, Texas this spring, which annually features student-designed low-cost global health technologies.
New Vascularized Patches Could Help Patient Recovery from Heart Attacks
Heart attacks are the result of a stoppage of blood flow to the heart – an interruption to normal function that can result in severe tissue damage, or even tissue death. This loss of healthy tissue function is one of the biggest challenges in treating patients that undergo heart attacks, as the damaged tissue increases their risk of having future attacks. One of the main solutions to this issue right now is the creation of cardiac tissue scaffolds using stem cells to create a platform for new and healthy tissue to grow in vivo. A group of biomedical engineers at Michigan Technological University hopes to expand on this basis by focusing not just on cellular alignment in the scaffold but on that of microvessels too. Led by Feng Zhao, Ph.D., Associate Professor of Biomedical Engineering, the team hopes that this new attention on microvessel organization will improve the vasculature of the scaffolds, and thus improve the success of the scaffolds in vivo, allowing for a better recovery from heart attacks.
Some Stem Cells May Be More Fit Than Others
Stem cells are one of the hottest research areas in the field of bioengineering today. Widely known as the cells in the human embryo that have the ability to eventually transform into specific cells for the brain, lung, and every other organ, stem cells are also of recent interest because researchers found ways to reverse this process, transforming organ-specific cells back to the pluripotent stem cell level. This achievement however, is mostly applicable to individual stem cells, and doesn’t fully encapsulate the way this process might work on a larger population level. So Peter Zandstra, Ph. D., a bioengineering faculty member at the University of British Columbia, decided to research just that.
Using mouse embryonic fibroblasts (MEFs), Zandstra and his lab attempted to track the cells throughout their reprogramming, to more clearly trace each back to its respective parent population. Surprisingly, they found that after only one week of reprogramming, nearly 80% of the original cell population had been removed, meaning that most of the parent generation was not “fit” enough to undergo the process of reprogramming, indicating that perhaps some stem cells will have a better chance of survival in this process than others. This research may suggest that not all cells have the capacity to undergo reprogramming, as many researchers originally thought.
A New Microdevice Will Help Model Bronchial Spasms
The difficulty in breathing associated with asthma is the result of bronchial spasms, which are a kind of muscle contraction in the airways. But little was known about just how these spasms occurred in patients, so Andre Levchenko, Ph.D., Professor of Biomedical Engineering at Johns Hopkins, and his lab created a microdevice to model them. Calling the device a “bronchi on a chip,” Levchenko and his team used a microphysiological model to look at some of the biochemical and mechanical signals associated with these kinds of muscle contractions. They found that the contractions operate in a positive feedback system, so that those caused by disturbance from allergens will subsequently cause even more contractions to occur. But surprisingly, they also found that a second contraction, if triggered at the right time during the initial contraction, could actually stop the process and allow the muscles to relax. Because asthma is a notoriously difficult disease to translate from animal to human models, this new device opens the door to understanding different mechanisms of asthma before taking research to clinical trials.
New CHOP Research Center to Focus Research on Pediatric Airway Disorders
A new bioengineering lab at the Children’s Hospital of Philadelphia called the Center for Pediatric Airway Disorders will specialize in a variety of airway procedures for pediatric patients such as tracheal reconstruction and recurrent laryngeal nerve reinnervation. This new lab will be one of the first to give a unique focus to the application of bioengineering to pediatric laryngology. The interdisciplinary center brings together students and researchers from all different fields, including materials science and microbiology, to find new ways of repairing tissue and regenerating organs related to respiratory disorders. Specific areas of research will involve the modeling of children’s vocal cords, understanding the mechanisms of fibrosis, and improving surgical procedures.
Deeper Understanding of Sickle Cell Anemia Could Lead to New Treatments
Though sickle cell anemia is a common and well-known disease, a new study of its causes at the nanoscale level might reveal previously unknown information about the assembly of hemoglobin fibers. Using microscopes with the ability to visualize these molecules at such a small level, researchers at the University of Minnesota found that the beginning organizations that lead to sickle cell anemia are much less ordered than originally thought. Led by Associate Professor of Biomedical Engineering David Wood, Ph.D., the team of researchers used this higher level of microscopy to find that hemoglobin self-assembly process, which was originally thought to be 96% efficient, is actually only 4% efficient. Wood hopes that this new knowledge will help allow for the development of new and better treatments for patients with sickle cell anemia, as there are currently only two FDA-approved ones on the market.
People & Places
Penn Today asked five Penn researchers about the women in STEM who have been a source of inspiration and encouragement throughout their own careers. Their responses include active researchers who have paved the way for better inclusion in STEM and famous female scientists from the past who broke boundaries as they made strides with their research.
Joel Boerckel, Ph.D, Assistant Professor of Orthopaedic Surgery and Bioengineering
This week, we want to congratulate Joel Boerckel, Ph.D., Assistant Professor of Orthopaedic Surgery and Bioengineering, and his lab on receiving a second R01 Grant from the National Institute of Arthritis and and Musculoskeletal Skin Diseases for their work on defining the roles of YAP and TAZ in embryonic bone morphogenesis and mechanoregulation of fracture repair. Dr. Boerckel is a member of the McKay Orthopaedic Research Laboratory.
We would also like to congratulate Christopher Yip, Ph. D., on being appointed as the new dean of the University of Toronto’s Faculty of Applied Science and Engineering. A professor in both the Department of Chemical Engineering and Applied Chemistry the Institute of Biomaterials and Biomedical Engineering, Dr. Yip’s research involves the use of molecular imaging to understand the self-assembly of proteins.
New ways of testing cancer treatments may now be possible thanks to researchers at the University of Akron who developed three-dimensional tumor models of triple-negative breast cancer. Led by 
A new technique that researchers from the Broad Institute of MIT and Harvard University are calling DNA microscopy could help map cells for better understanding of genetic and molecular complexities. 
Art, design, biology, and engineering all interact with each other in a 
A group of biomedical engineers at the University of Arkansas used a 
Heart attacks are the result of a stoppage of blood flow to the heart – an interruption to normal function that can result in severe tissue damage, or even tissue death. This loss of healthy tissue function is one of the biggest challenges in treating patients that undergo heart attacks, as the damaged tissue increases their risk of having future attacks. One of the main solutions to this issue right now is the creation of cardiac tissue scaffolds using stem cells to create a platform for new and healthy tissue to grow in vivo. A group of biomedical engineers at Michigan Technological University hopes to 
