Using Lung-on-a-chip Technology to Find Treatments for Chlorine Gas Exposure

Huh’s organ-on-a-chip devices contain human cells, allowing for experiments that could not otherwise be practically or ethically performed.

Chlorine gas is a commonly used industrial chemical. It is also highly toxic and potentially deadly; it was used as a chemical weapon in both World War I and the Syrian Civil War and has led to multiple deaths from industrial accidents. Mixing certain household cleaners can also produce the toxic gas, leading to lasting lung injuries for which there are currently no effective treatments.

Now, researchers at Penn Engineering and Penn’s Perelman School of Medicine are collaborating with BARDA, the U.S. Office of Health and Human Services’ Biomedical Advanced Research and Development Authority, to address this need using their lung-on-a-chip technology.

The laboratory of Dan Huh, associate professor in the Department of Bioengineering, has developed a series of organ-on-a-chip platforms. These devices incorporate human cells into precisely engineered microfluidic channels that mimic an organ’s natural environment, providing a way to conduct experiments that would not otherwise be feasible.

Dan Huh
Dan Huh, PhD

Huh’s previous research has involved using a placenta-on-a-chip to study which drugs are able to reach a developing fetus; investigating microgravity’s effect on the immune system by sending one of his chips to the International Space Station; and testing treatments for dry eye disease using an eye-on-a-chip, complete with a mechanical blinking eyelid.

Read the full story on Penn Engineering Today. Media contact Evan Lerner.

Magnetic Field and Hydrogels Could Be Used to Grow New Cartilage

by Frank Otto

MRI Knee joint or Magnetic resonance imaging sagittal view for detect tear or sprain of the anterior cruciate ligament (ACL).

Using a magnetic field and hydrogels, a team of researchers in the Perelman School of Medicine have demonstrated a new possible way to rebuild complex body tissues, which could result in more lasting fixes to common injuries, such as cartilage degeneration. This research was published in Advanced Materials.

“We found that we were able to arrange objects, such as cells, in ways that could generate new, complex tissues without having to alter the cells themselves,” says the study’s first author, Hannah Zlotnick, a graduate student in bioengineering who works in the McKay Orthopaedic Research Laboratory at Penn Medicine. “Others have had to add magnetic particles to the cells so that they respond to a magnetic field, but that approach can have unwanted long-term effects on cell health. Instead, we manipulated the magnetic character of the environment surrounding the cells, allowing us to arrange the objects with magnets.”

In humans, tissues like cartilage can often break down, causing joint instability or pain. Often, the breakdown isn’t in total, but covers an area, forming a hole. Current fixes are to fill those holes in with synthetic or biologic materials, which can work but often wear away because they are not the same exact material as what was there before. It’s similar to fixing a pothole in a road by filling it with gravel and making a tar patch: The hole will be smoothed out but eventually wear away with use because it’s not the same material and can’t bond the same way.

What complicates fixing cartilage or other similar tissues is that their makeup is complex.

“There is a natural gradient from the top of cartilage to the bottom, where it contacts the bone,” Zlotnick explains. “Superficially, or at the surface, cartilage has a high cellularity, meaning there is a higher number of cells. But where cartilage attaches to the bone, deeper inside, its cellularity is low.”

So the researchers, which included senior author Robert Mauck, PhD, director of the McKay Lab and a professor of Orthopaedic Surgery and Bioengineering, sought to find a way to fix the potholes by repaving them instead of filling them in. With that in mind, the research team found that if they added a magnetic liquid to a three-dimensional hydrogel solution, cells, and other non-magnetic objects including drug delivery microcapsules, could be arranged into specific patterns that mimicked natural tissue through the use of an external magnetic field.

Read more at Penn Medicine News.

Through Brain Imaging Analysis in Rats, Penn Researchers Show Potential to Predict Whether Pain Will be Acute or Persistent

Beth Winkelstein, Megan Sperry, and Eric Granquist

Pain may be a universal experience, but what actually causes that experience within our brains is still poorly understood. Pain often continues long after the relevant receptors in the body have stopped being stimulated and can persist even after those receptors cease to exist, as is the case with “phantom limb” pain.

The exact experience an individual will have after a painful incident comes down to the complex, variable connections formed between several different parts of the brain. The inability to predict how those connections will form and evolve can make pain management a tricky, frustrating endeavor for both healthcare providers and patients.

Now, a team of Penn researchers has shown a way to make such predictions from the pattern of neural connections that begin to take shape soon after the first onset of pain. Though their study was conducted in rats, it suggests that similar brain imaging techniques could be used to guide treatment decisions in humans, such as which individuals are most likely to benefit from different drugs or therapies.

The study, published in the journal Pain, was led by Beth Winkelstein, Eduardo D. Glandt President’s Distinguished Professor in Penn Engineering’s Department of Bioengineering and Deputy Provost of the University of Pennsylvania, along with Megan Sperry, then a graduate student in her lab. Eric Granquist, Director of the Center for Temporomandibular Joint Disease at the Hospital of the University of Pennsylvania in the Department of Oral & Maxillofacial Surgery, and assistant professor of Oral & Maxillofacial Surgery in Penn’s School of Dental Medicine, also contributed to the research.

“Our findings provide the first evidence that brain networks differ between acute and persistent pain states, even before those different groups of rats actually show different pain symptoms,” says Winkelstein.

Read the full story at Penn Engineering Today. Media contact Evan Lerner.

Engineering Bacteria-Killing Molecules from Wasp Venom

César de la Fuente, PhD

César de la Fuente a Presidential Assistant Professor in the Perelman School of Medicine’s departments of Psychiatry and Microbiology and Engineering’s department of Bioengineering, has racked up accolades for his innovative, computational approach to discovering new antibiotics.

Now, in his most recent study, de la Fuente has shown how these vital drugs might be derived from wasp venom.

The study, published in The Proceedings of the National Academy of Sciences, involved altering a highly toxic small protein from a common Asian wasp species, Vespula lewisii, the Korean yellow-jacket wasp. The alterations enhanced the molecule’s ability to kill bacterial cells while greatly reducing its ability to harm human cells. In animal models, de la Fuente and his colleagues showed that this family of new antimicrobial molecules made with these alterations could protect mice from otherwise lethal bacterial infections.

There is an urgent need for new drug treatments for bacterial infections, as many circulating bacterial species have developed a resistance to older drugs. The U.S. Centers for Disease Control & Prevention has estimated that each year nearly three million Americans are infected with antibiotic-resistant microbes and more than 35,000 die of them. Globally the problem is even worse: Sepsis, an often-fatal inflammatory syndrome triggered by extensive bacterial infection, is thought to have accounted for about one in five deaths around the world as recently as 2017.

“New antibiotics are urgently needed to treat the ever-increasing number of drug-resistant infections, and venoms are an untapped source of novel potential drugs. We think that venom-derived molecules such as the ones we engineered in this study are going to be a valuable source of new antibiotics,” says de la Fuente.

De la Fuente and his team started with a small protein, or “peptide,” called mastoparan-L, a key ingredient in the venom of Vespula lewisii wasps. Mastoparan-L-containing venom is usually not dangerous to humans in the small doses delivered by wasp stings, but it is quite toxic. It destroys red blood cells, and triggers a type of allergic/inflammatory reaction that in susceptible individuals can lead to a fatal syndrome called anaphylaxis—in which blood pressure drops and breathing becomes difficult or impossible.

Mastoparan-L (mast-L) also is known for its moderate toxicity to bacterial species, making it a potential starting point for engineering new antibiotics. But there are still some unknowns, including how to enhance its anti-bacterial properties, and how to make it safe for humans.

Continue reading at Penn Medicine News.

Brian Litt Receives NIH Pioneer Award to Develop Implantable Neurodevices

Brian Litt, MD

Brian Litt, professor in Engineering’s Department of Bioengineering and the Perelman School of Medicine’s departments of Neurology and Neurosurgery, has received a five-year, $5.6 million Pioneer Award from the National Institutes of Health, which will support his research on implantable devices for monitoring, recording and responding to neural activity.

The Pioneer Award is part of the agency’s High-Risk, High-Reward Research Program honoring exceptionally creative scientists. It challenges investigators to pursue new research directions and develop groundbreaking, high-impact approaches to a broad area of biomedical or behavioral science. Litt’s neurodevice research represents a new frontier in addressing a wide variety of neurological conditions.

In epilepsy, for example, these devices would predict and prevent seizures; in Parkinson’s patients, implants will measure and communicate with patients to improve mobility, reduce tremor and enhance responsiveness. Other implants might improve hearing or psychiatric symptoms by querying patient perceptions, feelings, and altering stimulation patterns algorithmically to improve them

Continue reading about Litt’s Pioneer Award at Penn Medicine News.

New Research from Penn Engineering and MIT Shows How Nanoparticles Can Turn Off Genes in Bone Marrow

Michael Mitchell
Michael Mitchell, PhD

by Evan Lerner

Using specialized nanoparticles, researchers from Penn Engineering and the Massachusetts Institute of Technology (MIT) have developed a way to turn off specific genes in cells of bone marrow, which play an important role in producing blood cells. These particles could be tailored to help treat heart disease or to boost the yield of stem cells in patients who need stem cell transplants.

This type of genetic therapy, known as RNA interference, is usually difficult to target to organs other than the liver, where nanoparticles would tend to accumulate. The researchers were able to modify their particles in such a way that they would accumulate in the cells found in the bone marrow.

In a recent Nature Biomedical Engineering study, conducted in mice, the researchers showed that they could use this approach to improve recovery after a heart attack by inhibiting the release of bone marrow blood cells that promote inflammation and contribute to heart disease.

“If we can get these particles to hit other organs of interest, there could be a broader range of disease applications to explore, and one that we were really interested in in this paper was the bone marrow. The bone marrow is a site for hematopoiesis of blood cells, and these give rise to a whole lineage of cells that contribute to various types of diseases,” says Michael Mitchell, Skirkanich Assistant Professor of Innovation in Penn Engineering’s Department of Bioengineering, one of the lead authors of the study.

Marvin Krohn-Grimberghe, a cardiologist at the Freiburg University Heart Center in Germany, and Maximilian Schloss, a research fellow at Massachusetts General Hospital (MGH), are also lead authors on the paper, which appears today in Nature Biomedical Engineering. The paper’s senior authors are Daniel Anderson, a professor of Chemical Engineering at MIT and a member of MIT’s Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science, and Matthias Nahrendorf, a professor of Radiology at MGH.

Mitchell’s expertise is in the design of nanoparticles and other drug delivery vehicles, engineering them to cross biological barriers that normally block foreign agents. In 2018, he received the NIH Director’s New Innovator Award to support research on delivering therapeutics to bone marrow, a key component of this new study.

The researchers have shown they can deliver nanoparticles to the bone marrow, influencing their function with RNA silencing. At top right, the bone marrow is not yet treated with particles that turn off a gene called SDF1. At bottom right, the number of neutrophils (blue) decreases, indicating that they have been released from bone marrow after treatment. At left, treatment with a control nanoparticle does not affect the number of neutrophils before and after treatment.

Read the full story at Penn Engineering Today.

A potential cause of CAR T side effects, and a path forward

Single cell sequencing aided researchers in identifying a previously undiscovered molecule in the brain.

Chimeric antigen receptor (CAR) T cell therapy has revolutionized treatment of leukemia, lymphoma, and multiple myeloma. But some people who have received this treatment experience neurotoxicity, or damage to the brain or nervous system.

New research from a team led by Avery Posey, an assistant professor of systems pharmacology and translational therapeutics in the Perelman School of Medicine, provides evidence that this side effect may owe to a molecule in the brain that scientists previously didn’t know was there.

The work, published in the journal Cell, revealed that the protein CD19 is present in brain cells that protect the blood-brain barrier. Prior to the finding, scientists believed CD19 was only expressed on B cells, and the protein served as a target for certain forms of CAR-T therapy. The discovery may chart a path forward for new strategies to effectively treat cancer while sparing the brain.

“The next question is,” says Posey, “can we identify a better target for eliminating B cell related malignancies other than CD19, or can we engineer around this brain cell expression of CD19 and build a CAR T cell that makes decisions based on the type of cell it encounters—for instance, CAR T cells that kill the B cells they encounter, but spare the CD19 positive brain cells?”

Read more at Penn Medicine News. Avery Posey is a member of the Department of Bioengineering Graduate Group.

Avery Posey’s cancer research takes high risks for big rewards

by Melissa Moody

Avery Posey, PhD (Image: Penn Medicine Newsby Melissa Moody

Much of the world, including research at Penn Medicine, has focused its attention on how T cells–which play a central role in immune response—might shape the trajectory of COVID-19 infection, and how immunotherapy can shed light on treatment of the disease.

Already a leader in immunotherapy research and treatment, Penn Medicine pioneered the groundbreaking development of CAR T cell cancer therapy. Avery Posey, an assistant professor of systems pharmacology and translational therapeutics, trained as a postdoctoral fellow in the lab of Carl June, who pioneered CAR T cell immunotherapy to treat cancer. Now as a faculty member at Penn, Posey has maintained a focus on T cell therapeutics, mostly for the treatment of cancer.

“This research combines two of my biggest interests—the use of gene therapy to treat disease and the investigation of little known biology, such as the roles of glycans in cell behavior. The pursuit of new knowledge, the roads less traveled—those are my inspirations,” Posey says.

Read more at Penn Medicine News.

N.B.: Avery Posey and Carl June are members of the Department of Bioengineering Graduate Group. Learn more about BE’s Grad Group Faculty here.

Penn Bioengineering’s Tsourkas Lab and Penn Start-up AlphaThera Awarded $667,000 SBIR Phase II Grant to Improve COVID-19 Detection Assays

To combat the COVID-19 pandemic caused by the SARS-CoV2 virus, Dr. Andrew Tsourkas’s Targeted Imaging Therapeutics and Nanomedicine (Titan) Lab in Penn Bioengineering, in collaboration with the Penn-based startup, AlphaThera, was recently awarded a $667,000 SBIR Phase II Grant Extension to support its efforts in commercializing COVID-19 detection technology. The grant supports work to address the growing need for anti-viral antibody testing. Specifically, the Tsourkas Lab and AlphaThera hope to leverage their expertise with antibody conjugation technologies to reduce the steps and complexity of existing detection assays to enable greater production and higher sensitivity tests. AlphaThera was founded in 2016 by Andrew Tsourkas, PhD, Professor of Bioengineering and James Hui, MD, PhD, a graduate of the Perelman School of Medicine and Penn Bioengineering’s doctoral program.

During this pandemic it is crucial to characterize disease prevalence among populations, understand immunity, test vaccine efficacy and monitor disease resurgence. Projections have indicated that millions of daily tests will be needed to effectively control the virus spread. One important testing method is the serological assay: These tests detect the presence of SARS-CoV2 antibodies in a person’s blood produced by the body’s immune system responding to infection. Serological tests not only diagnose active infections, but also establish prior infection in an individual, which can greatly aid in forecasting disease spread and contact tracing. To perform the serological assays for antibody detection, well-established immunoassay methods are used such as ELISA.

A variety of issues have slowed the distribution of these serological assays for antibody testing. The surge in demand for testing has caused shortages in materials and reagents that are crucial for the assays. Furthermore, complexity in some of the assay formats can slow both production and affect the sensitivity of test results. Recognizing these problems, AlphaThera is leveraging its novel conjugation technology to greatly improve upon traditional assay formats.

With AlphaThera’s conjugation technology, the orientation of antibodies can be precisely controlled so that they are aligned and uniformly immobilized on assay detection plates. This is crucial as traditional serological assays often bind antibodies to plates in a non-uniform manner, which increases variability of results and reduces sensitivity. See Fig 1 below. With AlphaThera’s uniform antibody immobilization, assay specificity could increase by as much as 1000- fold for detection of a patient’s SaRS-CoV2 antibodies.

Fig 1: Uniform vs Non-Uniform Immobilized Antibodies on Surface: Top is AlphaThera improvement, showing how antibodies would be uniformly immobilized and oriented on a plate for detection. Bottom is how many traditional serological assays immobilize antibodies, resulting in variability of results and lower specificity.

Furthermore, AlphaThera is addressing the shortage of assay reagents, specifically secondary antibody reagents, by removing certain steps from traditional serological assays. Rather than relying on secondary antibodies for detection of the patient antibodies, AlphaThera’s technology can label the patient SaRS-CoV2 primary antibodies directly in serum with a detection reagent. This eliminates several processing steps, reducing the time of the assay by as much as 50%, as well as the costs.

The Tsourkas Lab and AlphaThera have initiated their COVID-19 project, expanding into the Pennovation Center and onboarding new lab staff. Other antibody labeling products have also become available and are currently being prepared for commercialization. Check out the AlphaThera website to learn more about their technology at https://www.alphathera.com.

NIH SBIR Phase II Grant Extension— 5-R44-EB023750-03 (PI: Yu)  — 10/07/2020 – 10/07/2021

Danielle Bassett on ‘A Radical New Model of the Brain’

In a ‘Wired’ feature, Bassett helps explain the growing field of network neuroscience and how the form and function of the brain are connected.

Danielle Bassett, Ph.D.

Early attempts to understand how the brain works included the pseudoscience of phrenology, which theorized that various mental functions could be determined through the shape of the skull. While those theories have long been debunked, modern neuroscience has shown a kernel of truth to them: those functions are highly localized to different regions of the brain.

Now, Danielle Bassett, Professor of J. Peter Skirkanich Professor of Bioengineering and Electrical and Systems Engineering, is pioneering a new subfield that goes even deeper into the connection between the brain’s form and function: network neuroscience.

In a recent feature article in Wired, Bassett explains the concepts behind this new subfield. While prior understanding has long relied on the idea that certain areas of the brain control certain functions, Bassett and other network neuroscientists are using advances in imaging and machine learning to reveal the role the connections between those areas play.

For Bassett, one of the first indicators that these connections mattered more than previously realized was the shape of the neurons themselves.

Speaking with Wired’s Grace Huckins, Bassett says:

“Neurons are not spherical — neurons have a cell body, and then they have this long tail that allows them to connect to many other cells. You can even look at the morphology of the neuron and say, ‘Oh, well, connectivity has to matter. Otherwise, it wouldn’t look like this.’”

Read more about Bassett and the field of network neuroscience in Wired.

Originally posted on the Penn Engineering blog.