Week in BioE (August 16, 2019)

by Sophie Burkholder

Electrode Arrays and Star Wars Help to Inspire a New Prosthetic Arm

Brain-controlled prosthetic arm, Wikimedia commons

After nearly fifteen years of work, a new high-tech prosthetic arm from researchers at the University of Utah allows hand amputees to pluck grapes, pick up eggs without breaking them, and even put on their wedding rings. Named after Luke Skywalker’s robotic hand in the Star Wars saga, the LUKE Arm includes sensors that better mimic the way the human body sends information to the brain, allowing users to distinguish between soft and hard surfaces and to perform more complicated tasks. The arm relies heavily on an electrode array invented by University of Utah biomedical engineering professor Richard A. Normann, Ph.D., which is a bundle of microelectrodes that enable a computer to read signals from connected nerves in the user’s forearm.

But the biggest innovation in the use of these electrode arrays for the LUKE Arm is in the way they allow the prosthetic to mimic the sense of feeling on the surface of an object that indicates how much pressure should be applied when handling it. Gregory Clark, Ph.D., an associate professor of biomedical engineering at the University of Utah and the leader of the LUKE Arm project, says the key to improving these functions in the prosthetic was by more closely mimicking the path that this information takes to the brain, as opposed to merely what comprises that sensory information. In the future, Clark hopes to improve upon the LUKE Arm by including more inputs, like one for temperature data, and on making them more portable by eliminating the device’s need for computer connection.

Philly Voice Recognizes the Cremins Lab’s Innovations in Light-Activated Gene-Folding

While technological advancements over the past few decades have opened doors to understanding the topological structures of DNA, we still have far more to learn about how these structures impact and contribute to genome function. But here at Penn, the Cremins Laboratory in 3D Epigenomes and Systems Neurobiology hopes to fix that. Led by Jennifer E. Phillips-Cremins, Ph.D., members of the lab use light-activated dynamic looping (LADL) to better understand the way that genome topological properties and folding can affect protein translation. Cremins and her lab use this technique to force specific genome folds to interact with each other, and create temporary DNA loops that can then be bound together in the presence of blue light for certain proteins in the Arabidopsis plant. Using the data from these tests, researchers can better understand the genome structure-function relationships, and hopefully open the door to new treatments for diseases in which expression or mis-expression of certain genes is the cause.

Artificial Cells Can Deliver Molecules Better than the Real Thing

From pills to vaccines, ways to deliver drugs into the body have been constantly evolving since the early days of medicine.

Now, a new study from an interdisciplinary team led by researchers at the University of Pennsylvania provides a new platform for how drugs could be delivered to their targets in the future. Their work was published in the Proceedings of the National Academy of Sciences.

The research focuses on a dendrimersome, a compartment with a lamellar structure and size that mimic a living cell. It can be thought of as the shipping box of the cellular world that carries an assortment of molecules as cargo.

The scientists found that these dendrimersomes, which have a multilayered, onion-like structure, were able to “carry” high concentrations of molecules that don’t like water, which is common in pharmaceutical drugs. They were also able to carry these molecules more efficiently than other commercially available vessels. Additionally, the building block of the cell-like compartment, a janus dendrimer, is classified as an amphiphile, meaning it contains molecules that don’t like water and also molecules that are soluble in water, like lipids, that make up natural membranes.

“This is a different amphiphile that makes really cool self-assembled onions into which we were able to load a bunch of molecular cargos,” says co-author Matthew Good.

Read the rest of the story on Penn Today.

A Warm Evening Bath Could Improve Sleep Quality

In a recent review of over 5,000 sleep studies, biomedical engineering researchers at the University of Texas at Austin found a connection between water-based passive body heating and sleep onset latency, efficiency, and quality. Using meta-analytical tools to compare all of the studies and patient data, lead author and Ph.D. candidate Shahab Haghayegh and his team found that a warm bath in the temperature range of 104-109 degrees Fahrenheit taken 1-2 hours before bed has the ability to improve all three considered sleep categories. This makes sense considering that our body’s Circadian rhythms govern both our sleep cycles and temperature, bringing us to a higher temperature during the day and a lower one at night during sleep. In fact, this lowering of body temperature before sleep is what helps to trigger the onset of sleep, so taking a warm bath and allowing your body to cool down from it before going to sleep enhances the body’s own efforts of naturally cooling down before we go to bed. With this new and comprehensive review, those who suffer from poor sleep quality may soon find solace in temperature regulation therapy systems.

People & Places

With the recent 50th anniversary of the first moon landing by Americans Neil Armstrong, Buzz Aldrin, and Michael Collins in 1969, ABC News looked back at one of the women involved in the project. Judy Sullivan was a biomedical engineer at the time of the project, and served as the lead engineer of the biomedical system for Apollo 11. In this role, she led studies on the astronauts’ breathing rates and sensor capabilities for the devices being sent into space to help the astronauts monitor their health. For the Apollo 11 mission and a lot of Sullivan’s early work at NASA, she worked on teams of all men, as women were often encouraged to become teachers, secretaries, or homemakers over other professions. Today, Sullivan says she’s thrilled that women have more career options to choose from, and wants to continue seeing more women getting involved in math and science.

We would like to congratulate Sanjay Kumar, M.D., Ph.D., on his appointment as the new Department Chair of Bioengineering at the University of California, Berkeley. Since joining the faculty in 2005, Kumar has received several prestigious awards including the NSF Career Award, the NIH Director’s New Innovator Award, the Presidential Early Career Award for Scientists and Engineers, and the Berkeley student-voted Outstanding Teacher Award.

 

Penn Engineering’s Blinking Eye-on-a-Chip Used for Disease Modeling and Drug Testing

By Lauren Salig

Rachel Young, a graduate student in Huh’s lab, holds up the new eye-on-a-chip device. The latest iteration of the lab’s eye-on-a-chip has a mechanical eyelid to simulate blinking, and was used to test an experimental drug for dry eye disease. By incorporating human cells into an engineered scaffolding, the eye-on-a-chip has many of the benefits of testing on living subjects, while minimizing risks and ethical concerns.

People who spend eight or more hours a day staring at a computer screen may notice their eyes becoming tired or dry, and, if those conditions are severe enough, they may eventually develop dry eye disease (DED). DED is a common disease with shockingly few FDA-approved drug options, partially because of the difficulties of modeling the complex pathophysiology in human eyes. Enter the blinking eye-on-a-chip: an artificial human eye replica constructed in the laboratory of Penn Engineering researchers.

This eye-on-a-chip, complete with a blinking eyelid, is helping scientists and drug developers to improve their understanding and treatment of DED, among other potential uses. The research, published in Nature Medicine, outlines the accuracy of the eye-on-a-chip as an organ stand-in and demonstrates its utility as a drug testing platform.

Dan Huh and Jeongyun Seo

The study was led by Dan Huh, associate professor in the Department of Bioengineering, and graduate student Jeongyun Seo.

They collaborated with Vivian Lee, Vatinee Bunya and Mina Massaro-Giordano from the Department of Ophthalmology in Penn’s Perelman School of Medicine, as well as with Vivek Shenoy, Eduardo D. Glandt President’s Distinguished Professor in Penn Engineering’s Department of Materials Science and Engineering. Other collaborators included Woo Byun, Andrei Georgescu and Yoon-suk Yi, members of Huh’s lab, and Farid Alisafaei, a member of Shenoy’s lab.

Huh’s lab specializes in creating organs-on-a-chip that provide microengineered in vitro platforms to mimic their in vivo counterparts, including lung and bone marrow proxies launched into space this May to study astronaut illness. The lab has spent years fine-tuning its eye-on-a-chip, which earned them the 2018 Lush Prize for its promise in animal-free testing of drugs, chemicals, and cosmetics.

In this study, Huh and Seo focused on engineering an eye model that could imitate a healthy eye and an eye with DED, allowing them to test an experimental drug without risk of human harm.

The Huh lab’s eye-on-a-chip attached to a motorized, gelatin-based eyelid. Blinking spreads tears over the corneal surface, and so was a critical aspect to replicate in the researchers’ model of dry eye disease. cells. The cells of the cornea grow on the inner circle of scaffolding, dyed yellow, and the cells of the conjunctiva grow on the surrounding red circle. Artificial tears are supplied by a tear duct, dyed blue.

To construct their eye-on-a-chip, Huh’s team starts with a porous scaffold engineered with 3D printing, about the size of a dime and the shape of a contact lens, on which they grow human eye cells. The cells of the cornea grow on the inner circle of scaffolding, dyed yellow, and the cells of the conjunctiva, the specialized tissue covering the white part of human eyes, grow on the surrounding red circle. A slab of gelatin acts as the eyelid, mechanically sliding over the eye at the same rate as human blinking. Fed by a tear duct, dyed blue, the eyelid spreads artificial tear secretions over the eye to form what is called a tear film.

“From an engineering standpoint, we found it interesting to think about the possibility of mimicking the dynamic environment of a blinking human eye. Blinking serves to spread tears and generate a thin film that keeps the ocular surface hydrated. It also helps form a smooth refractive surface for light transmission. This was a key feature of the ocular surface that we wanted to recapitulate in our device,” says Huh.

For people with DED, that tear film evaporates faster than it’s replenished, resulting in inflammation and irritation. A common cause of DED is the reduced blinking that occurs during excessive computer usage, but people can develop the disease for other reasons as well. DED affects about 14 percent of the world’s population but has been notably difficult to develop new treatments for, with 200 failed clinical drug trials since 2010 and only two currently available FDA-approved drugs for treatment.

Huh’s lab has been considering the drug-testing potential of organs-on-a-chip since their initial conceptualization, and, because of its surface-level area of impact, DED seemed the perfect place to start putting their eye model to the test. But before they started a drug trial, the team had to ensure their model could really imitate the conditions of DED.

“Initially, we thought modeling DED would be as simple as just keeping the culture environment dry. But as it turns out, it’s an incredibly complex multifactorial disease with a variety of sub-types,” Huh says. “Regardless of type, however, there are two core mechanisms that underlie the development and progression of DED. First, as water evaporates from the tear film, salt concentration increases dramatically, resulting in hyperosmolarity of tears. And second, with increased tear evaporation, the tear film becomes thinner more rapidly and often ruptures prematurely, which is referred to as tear film instability. The question was: Is our model capable of modeling these core mechanisms of dry eye?”

The answer, after much experimentation, was yes. The team evoked DED conditions in their eye-on-a-chip by cutting their device’s artificial blinking in half and carefully creating an enclosed environment that simulated the humidity of real-life conditions. When put to the test against real human eyes, both healthy and with DED, the corresponding eye-on-a-chip models proved their similarity to the actual organ on multiple clinical measures. The eyes-on-a-chip mimicked actual eyes’ performance in a Schirmer strip, which tests liquid production; in an osmolarity test, which looks at tear film salt content; and in a keratography test, which evaluates the time it takes for a tear film to break up.

Having confirmed their eye-on-a-chip’s ability to mirror the performance of a human eye in normal and DED-inducing settings, Huh’s team turned to the pharmaceutical industry to find a promising DED drug candidate to test-drive their model. They landed on an upcoming drug based on lubricin, a protein primarily found in the lubricating fluid that protects joints.

“When people think of DED, they normally treat it as a chronic disease driven by inflammation,” says Huh, “but there’s now increasing evidence suggesting that mechanical forces are important for understanding the pathophysiology of DED. As the tear film becomes thinner and more unstable, friction between the eyelids and the ocular surface increases, and this can damage the epithelial surface and also trigger adverse biological responses such as inflammation. Based on these observations, there is emerging interest in developing ophthalmic lubricants as a topical treatment for dry eye. In our study, we used an lubricin-based drug that is currently undergoing clinical trials. When we tested this drug in our device, we were able to demonstrate its friction-lowering effects, but, more importantly, using this model we discovered its previously unknown capacity to suppress inflammation of the ocular surface.”

By comparing the testing results of their models of a healthy eye, an eye with DED, and an eye with DED plus lubricin, Huh and Seo were able to further scientists’ understanding of how lubricin works and show the drug’s promise as a DED treatment.

Similarly, the process of building a blinking eye-on-a-chip pushed forward scientists’ understanding of the eye itself, providing insights into the role of mechanics in biology. Collaborating with Shenoy, director of the Center for Engineering MechanoBiology, the team’s attention was drawn to how the physical blinking action was affecting the cells they cultivated to engineer an artificial eye on top of their scaffolding.

“Initially, the corneal cells start off as a single layer, but they become stratified and form multiple layers as a result of differentiation, which happens when these cells are cultured at the air-liquid interface. They also form tight cell-cell junctions and express a set of markers during differentiation,” Huh says. “Interestingly, we found out that mechanical forces due to blinking actually help the cells differentiate more rapidly and more efficiently. When the corneal cells were cultured under air in the presence of blinking, the rate and extent of differentiation increased significantly in comparison to static models without blinking. Based on this result, we speculate that blink-induced physiological forces may contribute to differentiation and maintenance of the cornea.”

In other words, human cornea cells growing on the scientists’ scaffold more quickly became specialized and efficient at their particular jobs when the artificial eyelid was blinking on top of them, suggesting that mechanical forces like blinking contribute significantly to how cells function. These types of conceptual advances, coupled with drug discovery applications, highlight the multifaceted value that engineered organs-on-a-chip can contribute to science.

Huh and Seo’s eye-on-a-chip is still just dipping its toes into the field of drug testing, but this first step is a victory that represents years of work refining their artificial eye to reach this level of accuracy and utility.

“Although we have just demonstrated proof-of-concept,” says Seo, “I hope our eye-on-a-chip platform is further advanced and used for a variety of applications besides drug screening, such as testing of contact lenses and eye surgeries in the future.”

“We are particularly proud of the fact that our work offers a great and rare example of interdisciplinary efforts encompassing a broad spectrum of research activities from design and fabrication of novel bioengineering systems to in vitro modeling of complex human disease to drug testing,” says Huh. “I think this is what makes our study unique and representative of innovation that can be brought about by organ-on-a-chip technology.”

This work was supported by the National Institutes of Health through grants 1DP2HL127720–0, R01EY026972 and K08EY025742–01, the National Science Foundation through grants CMMI:15–48571, and Research to Prevent Blindness.

Originally posted on the Penn Engineering Medium blog.

New data reveals cell size sparks genome awakening in embryos

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.”

Read more at Penn Medicine News.

Week in BioE (July 26, 2019)

by Sophie Burkholder

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.”

Read the full story on Penn Engineering’s Medium Blog. 

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.

 

Week in BioE (July 12, 2019)

by Sophie Burkholder

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.

Read more on Weinstein’s research in a recent New York Times profile piece.

Penn Engineers Demonstrate Superstrong, Reversible Adhesive that Works like Snail Slime

A snail’s epiphragm. (Photo: Beocheck)

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.

This study is a collaboration between Penn Engineering, Lehigh University’s Department of Bioengineering, and the Korea Institute of Science and Technology.

Read the full story on Penn Engineering’s Medium blog. 

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.

People and Places

Daeyeon Lee, professor in the Department of Chemical and Biomolecular Engineering and member of the Bioengineering Graduate Group Faculty here at Penn, has been selected by the U.S. Chapter of the Korean Institute of Chemical Engineers (KIChE) as the recipient of the 2019 James M. Lee Memorial Award.

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.”

Read the full story on Penn Engineering’s Medium blog.

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.

Penn Engineers’ ‘LADL’ Uses Light to Serve Up On-demand Genome Folding

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.

The study was published in the journal Nature Methods.

“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.

Originally published on the Penn Engineering Medium blog.

Week in BioE (June 28, 2019)

by Sophie Burkholder

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.

Read the rest of this story on Penn Today.

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.

 

Week in BioE (June 14, 2019)

by Sophie Burkholder

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.

Orsolya “Uschi” Symmons, a postdoctoral researcher at Penn in Associate Professor of Bioengineering Arjun Raj’s lab, led the research team along with Darío Lupiáñez at the Max-Delbrück Center for Molecular Medicine in Berlin, and Daniel Ibrahim at the Max Planck Institute for Molecular Geneticsin Berlin. Lil Bub’s owner, Mike Bridavsky, also contributed to the project.

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.

To read more of this story, visit Penn Engineering’s Medium Blog.

People and Places

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’s Organs-on-Chips and Organoids: Best of Both Worlds

By Lauren Salig

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.

Originally posted on the Penn Engineering Medium blog.

BE Freshmen Present Their Final Projects

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.