“Through their collaborative research, they are aiming to develop next-generation treatments for dental caries (tooth-decay) using lipid nanoparticles, the same delivery vehicles employed in the mRNA COVID-19 vaccine technology.
‘This project shows the type of innovative ideas and collaborations that we are kickstarting through the IDEA prize,’ says Dr. Michel Koo, co-director of the CiPD and Professor at Penn Dental Medicine. ‘This is a great example of synergistic interaction at the interface of engineering and oral health’ adds Dr. Kate Stebe, co-director of the CiPD and Professor at Penn Engineering.”
The Solomon R. Pollack Award for Excellence in Graduate Bioengineering Research is given annually to the most deserving Bioengineering graduate students who have successfully completed research that is original and recognized as being at the forefront of their field. This year, the Department of Bioengineering at the University of Pennsylvania recognizes the stellar work of four graduate students in Bioengineering.
Dissertation: “Ionizable Lipid Nanoparticles for mRNA CAR T Cell Engineering”
Margaret earned a bachelor’s degree in Biomedical Engineering from the University of Delaware where she conducted research in the Day Lab on the use of antibody-coated gold nanoparticles for the detection of circulating tumor cells. She conducted doctoral research in the lab of Michael J. Mitchell, J. and Peter Skirkanich Assistant Professor in Bioengineering. After defending her thesis at Penn in 2022, Margaret began postdoctoral training at the Massachusetts Institute of Technology (MIT) in the Hammond Lab where she is investigating the design and application of polymeric nanoparticles for combination therapies in ovarian cancer. She plans to use these experiences to continue a research career focused on drug delivery systems.
“Maggie was an absolutely prolific Ph.D. student in my lab, who pioneered the development of new mRNA lipid nanoparticle technology to engineer the immune system to target and kill tumor cells,” says Mitchell. “Maggie is incredibly well deserving of this honor, and I am so excited to see what she accomplishes next as a Postdoctoral Fellow at MIT and ultimately as a professor running her own independent laboratory at a top academic institution.”
Dissertation: “Designing Hyaluronic Acid Granular Hydrogels for Biomaterials Applications”
Victoria is currently a Princeton University Presidential Postdoctoral Research Fellow in the lab of Sujit S. Datta, where she studies microbial community behavior in 3D environments. She obtained her Ph.D. in 2022 as an NSF Graduate Research Fellow at Penn Bioengineering under the advisement of Jason A. Burdick, Adjunct Professor in Bioengineering at Penn and Bowman Endowed Professor in Chemical and Biological Engineering at the University of Colorado, Boulder. She received a B.ChE. in Chemical Engineering from the University of Delaware in 2018 as a Eugene DuPont Scholar. Outside of research, Victoria is highly active in volunteer and leadership roles within the American Institute of Chemical Engineers (AIChE), currently serving as Past Chair of the Young Professionals Community and a member of the Career and Education Operating Council (CEOC). Victoria’s career aspiration is to become a professor of chemical engineering and to lead a research program at the interaction of biomaterials, soft matter, and microbiology.
“Victoria was a fantastic Ph.D. student,” says Burdick. “She worked on important projects related to granular materials from the fundamentals to applications in tissue repair. She was also a leader in outreach activities, a great mentor to numerous undergraduates, and is already interviewing towards an independent academic position.”
Dissertation: “Characterizing Medial Temporal Lobe Neurodegeneration Due to Tau Pathology in Alzheimer’s Disease Using Postmortem Imaging”
Sadhana completed her B.S. in Electrical Engineering at the University of Cape Town, South Africa in 2014 and her M.S. in Biomedical Engineering from Carnegie Mellon University in 2017. Outside of the lab, she enjoys spending time in nature and exploring restaurants in Philadelphia with friends. She focused her doctoral work on the development of computational image analysis techniques applied to ex vivo human brain imaging data in the Penn Image Computing and Science Laboratory of Paul Yushkevich, Professor of Radiology at the Perelman School of Medicine and member of the Penn Bioengineering Graduate Group. She hopes to continue working at the intersection of machine learning and biomedical imaging to advance personalized healthcare and drug development.
“Dr. Sadhana Ravikumar’s Ph.D. work is a tour de force that combines novel methodological contributions crafted to address the challenge of anatomical variability in ultra-high resolution ex vivo human brain MRI with new clinical knowledge on the contributions of molecular pathology to neurodegeneration in Alzheimer’s disease,” says Yushkevich. “I am thrilled that this excellent contribution, as well as Sadhana’s professionalism and commitment to mentorship, have been recognized through the Sol Pollack award.”
Dissertation: “Remote Force Guided Assembly of Complex Orthopaedic Tissues”
Hannah was a Ph.D. candidate in the lab of Robert Mauck, Mary Black Ralston Professor in Orthopaedic Surgery and in Bioengineering. She successfully defended her thesis and graduated in August 2022. During her Ph.D., Hannah advanced the state-of-the-art in articular cartilage repair by harnessing remote fields, such as magnetism and gravity. Using these non-invasive forces, she was able to control cell positioning within engineered tissues, similar to the cell patterns within native cartilage, and enhance the integration between cartilage and bone. Her work could be used in many tissue engineering applications to recreate complex tissues and tissue interfaces. Hannah earned a B.S. in Biological Engineering from the Massachusetts Institute of Technology (MIT) in 2017 during which time she was also a member of the women’s varsity soccer team. At Penn, Hannah was also involved in the Graduate Association of Bioengineers (GABE) intramurals & leadership, and helped jumpstart the McKay DEI committee. Since completing her Ph.D., Hannah has begun her postdoctoral research as a Schmidt Science Fellow in Jason Burdick’s lab at the University of Colorado Boulder where she looks to improve in vitro disease models for osteoarthritis.
“Hannah was an outstanding graduate student, embodying all that is amazing about Penn BE – smart, driven, inventive and outstanding in every way,” says Mauck. “ I can’t wait to see where she goes and what she accomplishes!”
Congratulations to our four amazing 2023 Sol Pollack Award winners!
Congratulations to two Bioengineering graduate students who were awarded Student Travel Achievement Recognition (STAR) Awards from the Society for Biomaterials (SFB). The STAR Award recognizes research excellence and develops future leaders within SFB and comes with a certificate and a monetary award of $250. Penn Bioengineering graduate students Rebecca Haley and Alex Hamilton, both members of the lab of Michael J. Mitchell, Skirkanich Assistant Professor of Innovation in Bioengineering, received their awards and presented on their research in the SFB annual meeting in April 2023.
Rebecca Haley is a Ph.D. student in Bioengineering and a NSF Graduate Research Fellow. In the Mitchell Lab, she focuses on the use of ionizable lipid nanoparticles for the delivery of protein cargos. Supported by this STAR award, she presented her work delivering small protein RAS-inhibitors that reduce cancer cell proliferation. Rebecca is interested in expanding the applications of lipid nanoparticle technology, allowing currently limited therapeutics to achieve functional delivery and, hopefully, clinical success.
Alex Hamilton is a Ph.D. student in Bioengineering and an NSF Graduate Research Fellow. Alex’s work in the Mitchell lab focuses on non-viral nucleic acid delivery. His research interests include cancer immunotherapy, vaccines, and fetal-maternal medicine. He is currently engaged in using novel high-throughput screening techniques to accelerate the discovery process for lipid nanoparticle development for a variety of disease applications.
Two more Mitchell Lab members were likewise recognized with honorable mention inn the STAR Awards: Hannah Safford, a Ph.D. student in Bioengineering and NSF Fellow, and Rohan Palanki, a M.D.-Ph.D. student in Bioengineering and NIH Fellow
Learn more about the Mitchell Lab’s research in biomaterials science, drug delivery, and cellular and molecular bioengineering in the lab’s website.
Read more stories featuring Mitchell and his team here.
New research on reproductive health demonstrates the first successful delivery of mRNA to placental cells to treat pre-eclampsia at its root.
Pre-eclampsia is a leading cause of stillbirths and prematurity worldwide, occurring in 3 – 8 % of pregnancies. A disorder characterized by high maternal blood pressure, it results from insufficient vasodilation in the placenta, restricting blood flow from the mother to the fetus.
Currently, a health-care plan for someone with pre-eclampsia involves diet and movement changes, frequent monitoring, blood pressure management, and sometimes early delivery of the baby. These standards of care address symptoms of the condition, not the root cause, and further perpetuate health inequity.
Now, Penn engineers are addressing this longstanding gap in reproductive health care with targeted RNA therapy.
The COVID vaccines demonstrated how lipid nanoparticles (LNPs) efficiently deliver mRNA to target cells. The success of LNPs is opening doors for a variety of RNA therapies aiming to treat the root causes of illness and disease. However, drug development and health care have consistently neglected a portion of the population in need of targeted care the most – pregnant people and their babies.
In one of the first studies of its kind, published in the Journal of the American Chemical Society,Michael Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation in Bioengineering, and Kelsey Swingle, Ph.D. student in the Mitchell Lab and lead author, describe their development of an LNP with the ability to target and deliver mRNA to trophoblasts, endothelial cells, and immune cells in the placenta.
Once these cells receive the mRNA, they create vascular endothelial growth factor (VEGF), a protein that helps expand the blood vessels in the placenta to reduce the mother’s blood pressure and restore adequate circulation to the fetus. The researchers’ successful trials in mice may lead to promising treatments for pre-eclampsia in humans.
Savan Patel, a fourth year Penn Bioengineering student, is one of 42 finalists competing for a 2023 Hertz Fellowship in applied science, mathematics, and engineering, one of the most prestigious Ph.D. fellowships in the United States. Chosen annually, the Hertz Fellowship is awarded to the nation’s most promising graduate students in science and technology.
“Since 1963, the Hertz Foundation has granted fellowships empowering the nation’s most promising young minds in science and technology. Hertz Fellows receive five years of funding valued at up to $250,000, which offers flexibility from the traditional constraints of graduate training and the independence needed to pursue research that best advances our security and economic vitality […]
Over the foundation’s 60-year history of awarding fellowships, more than 1200 Hertz Fellows have established a remarkable track record of accomplishments. Their ranks include two Nobel laureates; recipients of 10 Breakthrough Prizes and three MacArthur Foundation “genius awards”; and winners of the Turing Award, the Fields Medal, the National Medal of Technology, and the National Medal of Science. In addition, 50 are members of the National Academies of Sciences, Engineering and Medicine, and 34 are fellows of the American Association for the Advancement of Science. Hertz Fellows hold over 3,000 patents, have founded more than 375 companies and have created hundreds of thousands of science and technology jobs.”
Patel is studying Bioengineering and Finance in the Jerome Fisher Program in Management and Technology (M&T), an interdisciplinary dual degree program coordinated by Penn Engineering and the Wharton School of Business. He is currently a member of the lab of Michael J. Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation in Bioengineering. Patel’s research interests lie at the interface of drug delivery and immunoengineering. His current project involves the use of modified cholesterol molecules to induce shifts in the biodistribution of ionizable lipid nanoparticles (LNPs). Following graduation, he intends to pursue a Ph.D. in bioengineering in which hopes to develop translatable immunotherapies and drug delivery platforms.
If chosen, the Hertz Fellowship will fund Patel’s graduate studies. Selected from over 750 applicants, Patel is one of fifteen undergraduates and one of two bioengineering students to make the final round of interviews. After a culminating round of interviews, the 2023 Class of Hertz Fellows will be announced in May.
Learn more about the Hertz Fellowship and read the full list of finalists here.
Engineers in the Center for Precision Engineering for Health (CPE4H) are focusing on innovations in diagnostics and delivery, cellular and tissue engineering, and the development of new devices that integrate novel materials with human tissues. Below is an excerpt from “Going Small to Win Big: Engineering Personalized Medicine,” featuring the research from the laboratory of Michael Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation in Bioengineering.
Solid tumors evade the immune system’s ability to attack them in part due to the tumors’ tough, fibrous biological barriers that circulating immune cells can’t cross. Researchers need to identify ways to deliver individualized treatments that can better target these tumors without causing damage to healthy tissues or affecting overall quality of life.
The Status Quo
Current cancer treatments typically involve surgery, radiation or chemo- therapy to eliminate solid tumors. These treatments are invasive and can cause numerous negative downstream effects. Newer treatments involve engineering a patient’s immune system to recognize and fight cancerous cells, but are so far only effective against certain “liquid” cancers, where the mutated cells circulate freely in the blood and bone marrow and are small enough to be picked off by the patient’s upgraded T cells. Additionally, existing methods can also require that the cell engineering take place in a lab rather than directly inside the body.
The Mitchell Lab’s Fix
Members of the lab of Michael Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation in Bioengineering, are looking to utilize nanoparticle delivery technology developed by their lab to engineer a different type of immune cell, the macrophage, in order to fight solid- tumor cancers from the inside.
The Mitchell lab is using lipid nanoparticles (LNPs) to carry mRNA and DNA sequences inside of macrophages, a type of immune cell that can consume tumor cells if engineered correctly. In theory, a patient would receive an injection carrying the LNP payload, and the macrophages, whose name literally means “big eaters,” would take up the genetic sequence, alter their function and be able to recognize a patient’s own unique tumor cells in the body.
Because of the way macrophages operate, they could cross the tumor’s biological barrier and attack the cells, destroying the tumor from the inside. An added benefit of the Mitchell Lab’s technology is that the destroyed tumor cells would then also allow other immune cells to present their antigens to circulating T cells, which could then learn to fight those same cancer cells in the future.
“One of the longstanding challenges that we face in the context of cancer and immunotherapies is that every tumor has unique antigens that are specific to patients,” says Mitchell. “This is why we’ve had a lot of trouble developing targeted therapies. Personalizing an approach by harnessing an individual’s immune system gives each patient a greater chance of a positive outcome.”
Since the success of the COVID-19 vaccine, RNA therapies have been the object of increasing interest in the biotech world. These therapies work with your body to target the genetic root of diseases and infections, a promising alternative treatment method to that of traditional pharmaceutical drugs.
Lipid nanoparticles (LNPs) have been successfully used in drug delivery for decades. FDA-approved therapies use them as vehicles for delivering messenger RNA (mRNA), which prompts the cell to make new proteins, and small interfering RNA (siRNA), which instruct the cell to silence or inhibit the expression of certain proteins.
The biggest challenge in developing a successful RNA therapy is its targeted delivery. Research is now confronting the current limitations of LNPs, which have left many diseases without an effective RNA therapy.
Liver fibrosis occurs when the liver is repeatedly damaged and the healing process results in the accumulation of scar tissue, impeding healthy liver function. It is a chronic disease characterized by the buildup of excessive collagen-rich extracellular matrix (ECM). Liver fibrosis has remained challenging to treat using RNA therapies due to a lack of delivery systems for targeting activated liver-resident fibroblasts. Both the solid fibroblast structure and the lack of specificity or affinity to target these fibroblasts has impeded current LNPs from entering activated liver-resident fibroblasts, and thus they are unable to deliver RNA therapeutics.
To tackle this issue and help provide a treatment for the millions of people who suffer from this chronic disease, Michael Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation in the Department of Bioengineering, and postdoctoral fellows Xuexiang Han and Ningqiang Gong, found a new way to synthesize ligand-tethered LNPs, increasing their selectivity and allowing them to target liver fibroblasts.
Lulu Xue, Margaret Billingsley, Rakan El-Mayta, Sarah J. Shepherd, Mohamad-Gabriel Alameh and Drew Weissman, Roberts Family Professor in Vaccine Research and Director of the Penn Institute for RNA Innovation at the Perelman School of Medicine, also contributed to this work.
Each year, the the Department of Bioengineering seeks exceptional candidates to conduct summer research in bioengineering with the support of two scholarships: the Abraham Noordergraaf Student Summer Bioengineering Research Fund and the Blair Undergraduate Research Fund in the Department of Bioengineering. These scholarships provide a living stipend for students to conduct research on campus in a Penn research lab under the mentorship of a faculty member. The Abraham Noordergraaf Student Summer Bioengineering Research Fund provides financial support for undergraduate or graduate summer research opportunities in bioengineering with a preference for study in the area of cardiovascular systems. Dr. Noordergraaf, who died in 2014, was a founding member and first chair of Penn Bioengineering. The Blair Undergraduate Research Fund in the Department of Bioengineering supports three to five undergraduate research scholars each year with the support of Dr. James C. Blair II. After a competitive round of proposals, the following six scholars were chosen for the Summer 2022 semester. Keep reading below for the research abstracts and bios of the awardees.
The Blair Undergraduate Research Fund in the Department of Bioengineering (Blair Scholars)
Student: Ella Atsavapranee (BE Class of 2023)
PI: Michael J. Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation, Bioengineering
“Lipid nanoparticle-mediated delivery of RAS protease to inhibit cancer cell growth”
Mutations in RAS, a family of proteins found in all human cells, drive a third of cancers, including many pancreatic, colorectal, and lung cancers. However, there are still no therapies that can effectively prevent RAS from causing tumor growth. Recently, a protease was engineered to specifically degrade active RAS, offering a promising new tool for treating these cancers. However, many protein-based therapies still cannot be effectively delivered to patients. Lipid nanoparticles (LNPs), which were used in the Pfizer-BioNTech and Moderna COVID-19 vaccines, have emerged as a promising platform for safe and effective delivery of both nucleic acids and proteins. We formulated a library of LNPs using different cationic lipids. We characterized the LNPs by size, charge, and pKa, and tested their ability to deliver fluorescently labeled protease. The LNPs were able to encapsulate and deliver a RAS protease, successfully reducing proliferation of colon cancer cells.
Ella is a senior from Maryland studying bioengineering and chemistry. She works in Dr. Michael Mitchell’s lab, developing lipid nanoparticles to deliver proteins that reduce cancer cell proliferation. She has also conducted research on early-stage cancer detection and therapy monitoring (at Stanford University) and drug delivery across the blood-brain barrier for neurodegenerative diseases (at University of Maryland). She is passionate about translational research, science communication, and promoting diversity in STEM.
Student: Chiadika Eleh (BE and CIS Class of 2024)
PI: Eric J. Brown, Associate Professor of Cancer Biology, Perelman School of Medicine
“Investigating Viability in ATR and WEE1 Inhibitor Treated Ovarian Cancer Cells”
High-grade serous ovarian cancers (HGSOCs) are an aggressive subtype of ovarian cancer, accounting for up to 80% of all ovarian cancer-related deaths. More than half of HGSOCs are homologous recombination deficient; thus, they lack a favorable response when treated with common chemotherapeutic trials. Therefore, new treatment strategies must be developed to increase the life expectancy and quality of life of HGSOC patients. To address the lack of effective treatment options, the Brown Lab is interested in combining ATR and WEE1 inhibition (ATRi/WEE1i) to target HGSOC cells. It has previously been shown that low-dose ATRi/WEE1i is an effective treatment strategy for CCNE1-amplified ovarian cancer-derived PDX tumors (Xu et al., 2021, Cell Reports Medicine). Therefore, the next step is to characterize the HGSOC-specific response to ATRi/WEE1i treatment. This project aims to characterize the viability phenotype of ovarian cancer (OVCAR3) cells in the presence of ATRi/WEE1i in both single and combination treatments. With further research, Eleh hopes to prove the hypothesis low-dose combination ATRi/WEE1i treatment will result in the synergistic loss of viability in OVCAR3 cells. This goal will be achieved through the treatment of OVCAR3 cells with ranging doses of ATRi and Wee1i over 24 and 48 hour time intervals. We hope that this data will help set a treatment baseline that can be used for all OVCAR30-based viability experiments in the future.
Chiadika Eleh is a Bioengineering and Computer Science junior and a member of Penn Engineering’s Rachleff Scholar program. As a Blair Scholar, she worked in Dr. Eric Brown’s cancer biology lab, where she studied cell cycle checkpoint inhibitors as a form of cancer treatment.
“Tbc1d2b regulates vascular formation during development and tissue repair after ischemia”
The mechanisms behind endothelial cells forming blood vessels remains unknown. We have identified Tbc1d2b as a protein that is integral to the regulation of vascular formation. In order to investigate the role of Tbc1d2b in tubule formation, fibrin gel bead assays will be conducted to evaluate how the presence of Tbc1d2b is required for angiogenesis. Fibrin gel bead assays simulate the extracellular matrix environment to support the in vitro development of vessels from human umbilical vein endothelial cells (HUVEC) coated on cytodex beads. In order to confirm the success of angiogenesis, immunostaining for Phalloidin and CD31 will be conducted. After confirmation that fibrin gel bead assays can produce in vitro tubules, sgRNA CRISPR knockout of Tbc1d2b will be performed on HUVEC cells which will then be used to conduct more fibrin gel bead assays. We hypothesize that HUVEC with the Tbc1d2b knockout phenotype will be unable to form tubules while wild type HUVEC will be able to.
Gloria Lee is a rising senior studying Bioengineering and Physics in the VIPER program from Denver, Colorado. Her research in Dr. Yi Fan’s lab focuses on the role that proteins play in cardiovascular tubule formation.
Abraham Noordergraaf Student Summer Bioengineering Research Fund (Noordergraaf Fellows)
Student: Gary Lin (Master’s in MEAM Class of 2023)
PI: Michelle J. Johnson, Associate Professor in Physical Medicine and Rehabilitation, Perelman School of Medicine, and in Bioengineering
“Development and Integration of Dynamically Modulating Control Systems in the Rehabilitation Using Community-Based Affordable Robotic Exercise System (Rehab CARES)”
As the number of stroke patients requiring rehabilitative care continues to increase, strain is being put onto the US health infrastructure which already has a shortage of rehabilitation practitioners. To help alleviate this pressure, a cost-effective robotic rehabilitative platform was developed to increase access to rehabilitative care. The haptic TheraDrive, a one-degree of freedom actuated hand crank that can apply assistive and resistive forces, was modified to train pronation and supination at the elbow and pinching of the fingers in addition to flexion and extension of the elbow and shoulder. Two controllers were created including an open-loop force controller and a closed-loop proportional-integral (PI) with adaptive control gains based on subject performance in therapy-game tasks as well as galvanic skin response. Stroke subjects (n=11) with a range of cognitive and motor impairment completed 4 therapy games in both adaptive and non-adaptive versions of the controllers (n=8) while measuring force applied on the TheraDrive handle. Resulting normalized average power versus Upper Extremity Fugl-Meyer (UE-FM) and Montreal Cognitive Assessment (MoCA) correlation analyses showed that power was strongly correlated with UE-FM in 2 of the conditions and moderately correlated with the other 6 while MoCA was moderate correlated to 2 of the conditions and weakly correlated to the rest. Mann-Whitney U-tests between adaptive and non-adaptive versions of each therapy game showed no significant differences with regards to power between controller types (p<0.05).
Gary is a master’s student in the School of Engineering studying Mechanical Engineering and Applied Mechanics with a concentration in Robotic and Mechatronic systems. His research primarily focuses on developing affordable rehabilitation robotics for use in assessment and game-based therapies post neural injury. Many of his interests revolve around the design of mechatronic systems and the algorithms used to control them for use in healthcare spaces.
“Optogenetic Control of Developing Kidney Cells for Future Treatment of End-Stage Renal Disease”
This project sought to build from prior research in the Hughes Lab on the geometric and mechanical consequences of kidney form on cell and tissue-scale function. While the developmental trajectory of the kidney is well understood, little is currently known about many factors affecting nephron progenitor differentiation rate. Insufficient differentiation of nephron progenitor cells during kidney formation can result in lower nephron number and glomerular density, which is a risk factor for progression to end-stage renal disease later in life. Prior studies indicated that the amount of nephron differentiation – and thus function of the adult kidney – is correlated to the packing of ureteric tubule tips present at the surface of the kidney. Building off of research conducted in the Bugaj Lab, we found that inserting an optogenetic construct into the genome of human embryonic kidney (HEK) cells allowed us to manipulate the contraction of those cells through exposing them to blue light. Manipulating the contraction of the cells allows for the manipulation of the packing of ureteric tubule tips at the kidney surface. We used a lentiviral vector to transduce HEK293 cells with the optogenetic construct and witnessed visible contraction of the cells when they were exposed to blue light. Future work will include using CRISPR-Cas9 to introduce the optogenetic construct into IPS cells.
Priya is a junior studying bioengineering and had the opportunity to work on manipulating developing kidney cells using an optogenetic construct in the Hughes Lab this summer. She is thrilled to continue this research throughout the coming school year. Outside of the lab, Priya is involved with the PENNaach dance team and the Society of Women Engineers, as well as other mentorship roles.
Student: Cosette Tomita (Master’s in MEAM Class of 2023)
“Expression and Characterization of an Anti-Aβ42 scFv”
Background: Amyloid Beta (Aβ42) fibrils contribute to the pathology of Alzheimer’s Disease. Numerous monoclonal antibodies have been developed against Aβ42. In this study we have designed and expressed a short chain variable fragment specific to Aβ42 (Anti-Aβ42 scFv). To characterize our anti-Aβ42 scFv we have performed structural analysis using transmission electron microscopy (TEM) and binding kinetics using microscale thermophoresis (MST) compared to commercially available antibodies 6E10, Aducanumab, and an IgG isotype control. The goal of this study is to determine if labeling densities and binding constants for Aducanumab and anti-Aβ42 scFv are not significantly different.
Method: To characterize Aβ42 fibril associated antibodies we used negative stain TEM. Aβ42 fibrils were stained on a glow discharged copper grid, and incubated with gold conjugated anti-Aβ42 scFv, 6E10—which binds all Aβ species, aducanumab, or IgG isotype control. Labeling densities were calculated as the number of fibril-associated gold particles per 1 μm2 for each image. Next, we used microscale thermophoresis determine the binding kinetics. Antibodies or anti-Aβ42 scFv were labeled with Alexa Fluor-647 and unlabeled Aβ42 was titrated in a serial dilution over 16 capillaries. The average fluorescence intensity was plotted against the antibody or scFv concentration and the curves were analyzed using the GraphPad Prism software to calculate the dissociation constant (KD) values.
Results: We found a significant difference, tested with a one-way ANOVA (P <0.0001), in gold particle associated Aβ fibrils per 1 μm2 between anti-Aβ42 scFv, 6E10, aducanumab, and IgG isotype control. Further analysis of aducanumab and 6CO3 with unpaired student t-test indicates significant differences in fibril associated gold particles between aducanumab vs. 6E10 (P=0.0003), Aducanumab vs. Isotype control (P <0.0001), anti-Aβ42 scFv vs 6E10 (p=0.0072), and anti-Aβ42 scFv vs Isotype Control (P=0.0029) with no significant difference in labeling densities between Aducanumab and anti-Aβ42 scFv. The expected KD values from MST were 1.8μM for Aducanumab and anti-Aβ42 scFv, 10.3nM for 6E10 and no expected binding for the isotype control. The experimental KD values for anti-Aβ42 scFv and 6E10 are 0.1132μM and 1.467μM respectively. The KD value for Isotype control was undetermined, as expected, however, the KD for Aducanumab was undetermined due to suboptimal assay conditions. Due to confounding variables in the experimental set up such as the use of Aβ1-16 compared to Aβ42 and the use of different fluorophores—5-TAMRA, Alexa Fluor 647 or FITC— the experimental KD values were off by several orders of magnitude.
Conclusion: We have illustrated similar labeling densities between Aducanumab and our anti-Aβ42 scFv. In the future, we will further optimize the MST assay conditions and compare the KD values obtained by MST with other techniques such as surface plasma resonance.
Cosette was born and raised in Chicago land area. Go Sox! She attended University of Missouri where she majored in Chemistry and Biology. She synthesized sigma-2 radiotracers and developed advanced skills in biochemical techniques in Dr. Susan Lever’s lab. After graduation, she moved to NJ to work at Lantheus, a radiopharmaceutical company. She missed academia and the independence of program and project development, so she came to work at the Penn Cyclotron facility before entering the Bioengineering master’s program.
Michael Mitchell, J. Peter and Geri Skirkanich Assistant Professor of Innovation in the Department of Bioengineering, is one of this year’s recipients of the National Science Foundation’s CAREER Award. The award is given to early-career faculty researchers who demonstrate the potential to be role models in their field and invest in the outreach and education of their work.
Mitchell’s award will fund research on techniques for “immunoengineering” macrophages. By providing new instructions to these cells via nanoparticles laden with mRNA and DNA sequences, the immune system could be trained to target and eliminate solid tumors. The award will also support graduate students and postdoctoral fellows in his lab over the next five years.
The project aligns with Mitchell’s larger research goals and the current explosion of interest in therapies that use mRNA, thanks to the technological breakthroughs that enabled the development of COVID-19 vaccines.
“The development of the COVID vaccine using mRNA has opened doors for other cell therapies,” says Mitchell. “The high-priority area of research that we are focusing on is oncological therapies, and there are multiple applications for mRNA engineering in the fight against cancer.”
A new wave of remarkably effective cancer treatments incorporates chimeric antigen receptor T-cell (CAR-T) therapy. There, a patient’s T-cells, a type of white blood cell that fights infections, are genetically engineered to identify, target and kill individual cancer cells that accumulate in the circulatory system.
However, despite CART-T therapy’s success in treating certain blood cancers, the approach is not effective against cancers that form solid tumors. Because T-cells are not able to penetrate tumors’ fibrous barriers, Mitchell and his colleagues have turned to another part of the immune system for help.
With one of its key missions to develop a new generation of scientists at the interface of dental medicine and engineering, the Center for Innovation & Precision Dentistry (CiPD) has selected its inaugural class of fellows for its new postdoctoral training program.
The CiPD was awarded a $2.5 million T90/R90 grant from the National Institute of Dental and Craniofacial Research (NIDCR) last summer to establish the program, recently naming this first cohort of fellows that includes Justin Burrell, Marshall Padilla, Zhi Ren, and Dennis Sourvanos.
“We’re hoping this program will promote cross-pollination and create a culture between these two fields to help dentists develop innovative strategies with engineers,” says Penn Dental Medicine’s Michel Koo, Co-Director of CiPD, who launched the Center in 2021 with Co-Director Kathleen Stebe, Richer & Elizabeth Goodwin Professor in Penn Engineering’s Department of Chemical and Biomolecular Engineering. “Dentists can learn from engineering principles and tools, and engineers can understand more about the needs of the dental and craniofacial fields. We’re providing a platform for them to work together to address unmet clinical needs and develop careers in that interface.”
The NIDCR T90/R90 Postdoctoral Training Program aims to specifically focus on the oral microbiome, host immunity, and tissue regeneration, each of which ties into different aspects of oral health, from tooth decay and periodontal disease to the needs of head and neck cancer patients. To advance these areas, emerging approaches, from advanced materials, robotics, and artificial intelligence to tissue engineering, chloroplast- and nanoparticle-based technologies, will be leveraged.
As part of the two-year training, each postdoc will receive co-mentorship from faculty from each school in conjunction with a career development committee of clinicians, basic scientists, as well as engineers. These mentorships will be focused on research outcomes and readying participants to submit grants and compete for positions in academia or industry.
The inaugural class of fellows includes Justin Burrell, a postdoctoral student in the lab of D. Kacy Cullen, Associate Professor of Neurosurgery; Marshall Padilla, a postdoc in the lab of Michael J. Mitchell, Skirkanich Assistant Professor of Innovation in Bioengineering; and Zhi Ren, a postdoc in the lab of Michael Koo; and Dennis Sourvanos, an Advanced Graduate Dental Education resident at Penn Dental Medicine whose research has been co-directed by Timothy C. Zhu, Professor of Radiation Oncology in the Perelman School of Medicine. Cullen, Mitchell, Koo and Zhu are all members of the Penn Bioengineering Graduate Group.