Deconstructing the Mechanics of Bone Marrow Disease

by Katherine Unger Baillie

Acollaborative team developed an alginate-based hydrogel system that mimics the viscoelasticity of the natural extracellular matrix in bone marrow. By tweaking the balance between elastic and viscous properties in these artificial ECMs, they could recapitulate the viscoelasticity of healthy and scarred fibrotic bone marrow, and study the effects on human monocytes placed into these artificial ECMs. (Image: Adam Graham/Harvard CNS/Wyss Institute at Harvard University)

Fibrosis is the thickening of various tissues caused by the deposition of fibrillar extracellular matrix (ECM) in tissues and organs as part of the body’s wound healing response to various forms of damage. When accompanied by chronic inflammation, fibrosis can go into overdrive and produce excess scar tissue that can no longer be degraded. This process causes many diseases in multiple organs, including lung fibrosis induced by smoking or asbestos, liver fibrosis induced by alcohol abuse, and heart fibrosis often following heart attacks. Fibrosis can also occur in the bone marrow, the spongy tissue inside some bones that houses blood-producing hematopoietic stem cells (HSCs) and can lead to scarring and the disruption of normal functions.

Chronic blood cancers known as “myeloproliferative neoplasms” (MPNs) are one example, in which patients can develop fibrotic bone marrow, or myelofibrosis, that disrupts the normal production of blood cells. Monocytes, a type of white blood cell belonging to the group of myeloid cells, are overproduced from HSCs in neoplasms and contribute to the inflammation in the bone marrow environment, or niche. However, how the fibrotic bone marrow niche itself impacts the function of monocytes and inflammation in the bone marrow was unknown.

Now, a collaborative team from PennHarvard, the Dana-Farber Cancer Institute (DFCI), and Brigham and Women’s Hospital has created a programmable hydrogel-based in vitro model mimicking healthy and fibrotic human bone marrow. Combining this system with mouse in vivo models of myelofibrosis, the researchers demonstrated that monocytes decide whether to enter a pro-inflammatory state and go on to differentiate into inflammatory dendritic cells based on specific mechanical properties of the bone marrow niche with its densely packed ECM molecules. Importantly, the team found a drug that could tone down these pathological mechanical effects on monocytes, reducing their numbers as well as the numbers of inflammatory myeloid cells in mice with myelofibrosis. The findings are published in Nature Materials.

“We found that stiff and more elastic slow-relaxing artificial ECMs induced immature monocytes to differentiate into monocytes with a pro-inflammatory program strongly resembling that of monocytes in myelofibrosis patients, and the monocytes to differentiate further into inflammatory dendritic cells,” says co-first author Kyle Vining, who recently joined Penn’s School of Dental Medicine and School of Engineering and Applied Science as an assistant professor of preventive and restorative sciences. “More viscous fast-relaxing artificial ECMs suppressed this myelofibrosis-like effect on monocytes. This opened up the possibility of a mechanical checkpoint that could be disrupted in myelofibrotic bone marrow and also may be at play in other fibrotic diseases.”

Vining worked on the study as a postdoctoral fellow at Harvard in the lab of David Mooney. “Our study shows that the differentiation state of monocytes, which are key players in the immune system, is highly regulated by mechanical changes in the ECM they encounter,” says Mooney, who co-led the study with DFCI researcher Kai Wucherpfennig. “Specifically, the ECM’s viscoelasticity has been a historically under-appreciated aspect of its mechanical properties that we find correlates strongly between our in vitro and the in vivo models and human disease. It turns out that myelofibrosis is a mechano-related disease that could be treated by interfering with the mechanical signaling in bone marrow cells.”

Continue reading at Penn Today

Alexander Buffone Appointed Assistant Professor at New Jersey Institute of Technology

Alexander Buffone, Ph.D.

Penn Bioengineering is proud to congratulate Alexander Buffone, Ph.D. on his appointment as Assistant Professor in the Department of Biomedical Engineering at New Jersey Institute of Technology. His appointment began in the Spring of 2022.

Buffone got his Ph.D. in Chemical Engineering from SUNY Buffalo in Buffalo, NY in 2012, working with advisor Sriram Neelamegham, Professor of Chemical and Biological Engineering. Buffone completed previous postdoctoral studies at Roswell Park Comprehensive Cancer Center with Joseph T.Y. Lau, Distinguished Professor of Oncology in the department of Cellular and Molecular Biology. Upon coming to Penn in 2015, Buffone has worked in the Hammer Lab under advisor Daniel A. Hammer, Alfred G. and Meta A. Ennis Professor in Bioengineering and in Chemical and Biomolecular Engineering, first as a postdoc and later a research associate. Buffone also spent a year as a Visiting Scholar in the Center for Bioengineering and Tissue Regeneration, directed by Valerie M. Weaver, Professor at the University of California, San Francisco in 2019.

While at Penn, Buffone was a co-investigator on an R21 grant through the National Institutes of Health (NIH) which supported his time as a research associate. Buffone is excited to start his own laboratory where he plans to train a diverse set of trainees.

Buffone’s research area lies at the intersection of genetic engineering, immunology, and glycobiology and addresses how to specifically tailor the trafficking and response of immune cells to inflammation and various diseases. The work seeks to identify and subsequently modify critical cell surface and intracellular signaling molecules governing the recruitment of various blood cell types to distal sites. The ultimate goal of his research is to tailor and personalize the innate and adaptive immune response to specific diseases on demand.

“None of this would have been possible without the unwavering support of all of my mentors, past and present, and most especially Dan Hammer,” Buffone says. “His support in helping me transition into an independent scientist and his understanding of my outside responsibilities as a dad with two young children is truly the reason why I am standing here today. It’s a testament to Dan as both a person and a mentor.”

Shapeshifting Microrobots Can Brush and Floss Teeth

by Katherine Unger Baillie

In a proof-of-concept study, researchers from the School of Dental Medicine and School of Engineering and Applied Science shows that a hands-free system could effectively automate the treatment and removal of tooth-decay-causing bacteria and dental plaque. (Illustration: Melissa Pappas)

A shapeshifting robotic microswarm may one day act as a toothbrush, rinse, and dental floss in one.

The technology, developed by a multidisciplinary team at the University of Pennsylvania, is poised to offer a new and automated way to perform the mundane but critical daily tasks of brushing and flossing. It’s a system that could be particularly valuable for those who lack the manual dexterity to clean their teeth effectively themselves.

The building blocks of these microrobots are iron oxide nanoparticles that have both catalytic and magnetic activity. Using a magnetic field, researchers could direct their motion and configuration to form either bristlelike structures that sweep away dental plaque from the broad surfaces of teeth, or elongated strings that can slip between teeth like a length of floss. In both instances, a catalytic reaction drives the nanoparticles to produce antimicrobials that kill harmful oral bacteria on site.

Experiments using this system on mock and real human teeth showed that the robotic assemblies can conform to a variety of shapes to nearly eliminate the sticky biofilms that lead to cavities and gum disease. The Penn team shared their findings establishing a proof-of-concept for the robotic system in the journal ACS Nano.

“Routine oral care is cumbersome and can pose challenges for many people, especially those who have hard time cleaning their teeth” says Hyun (Michel) Koo, a professor in the Department of Orthodontics and divisions of Community Oral Health and Pediatric Dentistry in Penn’s School of Dental Medicine and co-corresponding author on the study. “You have to brush your teeth, then floss your teeth, then rinse your mouth; it’s a manual, multistep process. The big innovation here is that the robotics system can do all three in a single, hands-free, automated way.”

Read the full story in Penn Engineering Today.

Hyun (Michel) Koo is a professor in the Department of Orthodontics and divisions of Community Oral Health and Pediatric Dentistry in the School of Dental Medicine, co-director of the Center for Innovation & Precision Dentistry, and member of the Penn Bioengineering Graduate Group at the University of Pennsylvania.

Edward Steager is a senior research investigator in Penn’s School of Engineering and Applied Science.

Koo and Steager’s coauthors on the paper are Penn Dental Medicine’s Min Jun Oh, Alaa Babeer, Yuan Liu, and Zhi Ren and Penn Engineering’s Jingyu Wu, David A. Issadore, Kathleen J. Stebe, and Daeyeon Lee.

This work was supported in part by the National Institute for Dental and Craniofacial Research (grants DE025848 and DE029985), Procter & Gamble, and the Postdoctoral Research Program of Sungkyunkwan University.

Spencer Haws Receives Druckenmiller Fellowship

Spencer Haws, Ph.D.

Spencer Haws, Postdoctoral Research Fellow in the laboratory of Jennifer E. Phillips-Cremins, Associate Professor and Dean’s Faculty Fellow in Bioengineering and in Genetics, was awarded a 2022 Druckenmiller Fellowship from the New York Stem Cell Foundation Research Institute (NYSCF). This prestigious program is the largest dedicated stem cell fellowship program in the world and was developed to train and support young scientists working on groundbreaking research in the field of stem cell research. Haws is one of only five inductees into the 2022 class of fellows.

Haws earned his Ph.D. in Nutritional Sciences in 2021 from the University of Wisconsin-Madison, where he studied metabolism-chromatin connections under the mentorship of John Denu, Professor in Biomolecular Chemistry at the University of Wisconsin-Madison. As a NYSCF – Druckenmiller Fellow in the Cremins Laboratory for Genome Architecture and Spatial Neurobiology, Haws is using this previously developed expertise to frame his investigations into the underlying mechanisms driving the neurodegenerative disorder fragile X syndrome (FXS). “Ultimately, I hope that this work will help guide the development of future FXS-specific therapeutics of which none currently exist,” says Haws.

Read the full list of 2022 Druckenmiller Fellows and view introductory videos on the NYSCF website.

Penn Bioengineer Develops Technology to Keep Track of Living Cells and Tissues

SAFE Bioorthogonal Cycling

Cells in complex organisms undergo frequent changes, and researchers have struggled to monitor these changes and create a comprehensive profile for living cells and tissues. Historically researchers have been limited to only 3-5 markers due to spectral overlaps in fluorescence microscopy, an essential tool required for imaging cells. With only this small handful of markers, it is difficult to monitor protein expressions of live cells and a comprehensive profile of cellular dynamics cannot be created. However, a new study in Nature Biotechnology addresses these limitations by demonstrating a new method for comprehensive profiling of living cells.

Jina Ko, PhD

Jina Ko, Assistant Professor in Bioengineering in the School of Engineering and Applied Science and in Pathology and Laboratory Medicine in the Perelman School of Medicine, served as lead author of this new study. Ko conducted postdoctoral research at Massachusetts General Hospital (MGH) and the Wyss Institute at Harvard University, and the work for this study was done in collaboration with Jonathan Carlson M.D., Ph.D. and Ralph Weissleder M.D., Ph.D. of MGH. Ko’s lab at Penn develops novel technologies using bioengineering, molecular biology, and chemistry to address diagnostic challenges for precision medicine.

To address these limitations in microscopy, Ko’s team developed a new chemistry tool which was highly gentle to cells. This “scission-accelerated fluorophore exchange (or SAFE)” method utilizes “click” chemistry, a type of chemistry that follows examples found in nature to create fast and simple reactions. This new SAFE method enabled Ko to achieve non-toxic conditions to living cells and tissues, whereas previous methods have used harsh chemicals that would strip off fluorophores and consequently would not work with living cells and tissues.

With the development of SAFE, the authors demonstrated that researchers can now effectively perform multiple cycles of cell profiling and can monitor cellular changes over the course of their observations. Instead of the previous limitation of 3-5 markers total, SAFE allows for many more cycles and can keep track of almost as many markers as the researcher wants. One can now stain cells and quench/release fluorophores and repeat the cycle multiple times for multiplexing on living cells. Each cycle can profile 3 markers, and so someone interested in profiling 15 markers could easily perform 5 cycles to achieve this much more comprehensive cell profile. With this breakthrough in more detailed imaging of cells, SAFE demonstrates broad applicability for allowing researchers to better investigate the physiologic dynamics in living systems.

Read the paper, “Spatiotemporal multiplexed immunofluorescence imaging of living cells and tissues with bioorthogonal cycling of fluorescent probes,” in Nature Biotechnology.

This study was supported by the Schmidt Science Fellows in Partnership with the Rhodes Trust and National Institutes of Health, National Cancer Institute (K99CA256353).

Bioengineering Graduate Student Hannah Zlotnick Named Schmidt Science Fellow

by Evan Lerner

Hannah Zlotnick

Hannah Zlotnick, a graduate student in the Department of Bioengineering and a member of the McKay Orthopaedic Research Laboratory in Penn’s Perelman School of Medicine, has been named a Schmidt Science Fellow.

She joins 28 early-career scientists from around the world in this year’s cohort, with each receiving support for one to two years, $100,000 in salary support per year, individualized mentoring, and a series of professional development sessions as they pivot to the next stages of their research agendas.

The fellowship is a program of Schmidt Futures, the philanthropic initiative of Eric and Wendy Schmidt that aims to tackle society’s toughest challenges by supporting interdisciplinary researchers at the start of their careers.

“Our latest group of Schmidt Science Fellows embodies our vision for this Program at its inception five years ago,” says Eric Schmidt, co-founder of Schmidt Futures and former CEO and Chairman of Google. “We find the most talented next-generation leaders from around the world and back these impressive young adults with the resources and networks they need to realize their full potential while addressing some of the big scientific questions facing the world. Congratulations to the 2022 Schmidt Science Fellows, I am excited to see where your science takes you and what you will achieve.”

Working at the intersection of materials science, biology, and applied clinical research, Zlotnick’s postdoctoral work will involve developing advanced bioprinting techniques for regenerative medicine. Such advances are necessary to recreate the multi-cellular composition of orthopedic tissues, such as those found in the knee joint. Lab-grown tissue models can then be used to broaden our understanding of how degenerative diseases progress after injury, limit the need for animal models, and serve as a platform for therapeutic discovery.

Read the full story in Penn Engineering Today.

How Bacteria Stores Information to Kill Viruses (But Not Themselves)

by Luis Melecio-Zambrano

A group of bacteriophages, viruses that infect bacteria, imaged using transmission electron microscopy. New research sheds light on how bacteria fight off these invaders without triggering an autoimmune response. (Image: ZEISS Microscopy, CC BY-NC-ND 2.0)

During the last few years, CRISPR has grabbed headlines for helping treat patients with conditions as varied as blindness and sickle cell disease. However, long before humans co-opted CRISPR to fight genetic disorders, bacteria were using CRISPR as an immune system to fight off viruses.

In bacteria, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) works by stealing small pieces of DNA from infecting viruses and storing those chunks in the genes of the bacteria. These chunks of DNA, called spacers, are then copied to form little tags, which attach to proteins that float around until they find a matching piece of DNA. When they find a match, they recognize it as a virus and cut it up.

Now, a paper published in Current Biology by researchers from the University of Pennsylvania Department of Physics and Astronomy shows that the risk of autoimmunity plays a key role in shaping how CRISPR stores viral information, guiding how many spacers bacteria keep in their genes, and how long those spacers are.

Ideally, spacers should only match DNA belonging to the virus, but there is a small statistical chance that the spacer matches another chunk of DNA in the bacteria itself. That could spell death from an autoimmune response.

“The adaptive immune system in vertebrates can produce autoimmune disorders. They’re very serious and dangerous, but people hadn’t really considered that carefully for bacteria,” says Vijay Balasubramanian, principal investigator for the paper and the Cathy and Marc Lasry Professor of Physics in the School of Arts & Sciences.

Balancing this risk can put the bacteria in something of an evolutionary bind. Having more spacers means they can store more information and fend off more types of viruses, but it also increases the likelihood that one of the spacers might match the DNA in the bacteria and trigger an autoimmune response.

Read the full story in Penn Today.

Vijay Balasubramanian is the Cathy and Marc Lasry Professor of Physics at the Department of Physics and Astronomy of the University of Pennsylvania, a visiting professor at Vrije Universiteit Brussel, and a member of the Penn Bioengineering Graduate Group.

FDA Approves Penn Pioneered CAR T Cell Therapy for Third Indication

The U.S. Food and Drug Administration has expanded its approval for Kymriah, a personalized cellular therapy developed at the Abramson Cancer Center, this time for the treatment of adults with relapsed/refractory follicular lymphoma who have received at least two lines of systemic therapy. “Patients with follicular lymphoma who relapse or don’t respond to treatment have a poor prognosis and may face a series of treatment options without a meaningful, lasting response,” said Stephen J. Schuster, the Robert and Margarita Louis-Dreyfus Professor in Chronic Lymphocytic Leukemia and Lymphoma in the Division of Hematology Oncology. It’s the third FDA approval for the “living drug,” which was the first of its kind to be approved, in 2017, and remains the only CAR T cell therapy approved for both adult and pediatric patients.

“In just over a decade, we have moved from treating the very first patients with CAR T cell therapy and seeing them live healthy lives beyond cancer to having three FDA-approved uses of these living drugs which have helped thousands of patients across the globe,” said Carl June, MD, the Richard W. Vague Professor in Immunotherapy in the department of Pathology and Laboratory Medicine in Penn’s Perelman School of Medicine and director of the Center for Cellular Immunotherapies in the Abramson Cancer Center and director of the Parker Institute for Cancer Immunotherapy at Penn. “Today’s news is new fuel for our work to define the future of cell therapy and set new standards in harnessing the immune system to treat cancer.”

Research from June, a member of the Penn Bioengineering Graduate Group, led to the initial FDA approval for the CAR T therapy (sold by Novartis as Kymriah) for treating acute lymphoblastic leukemia (ALL), one of the most common childhood cancers.

Read the full announcement in Penn Medicine News.

César de la Fuente Receives 2022 RSEQ Young Investigator Award

César de la Fuente, PhD

César de la Fuente, Presidential Assistant Professor in Psychiatry, Bioengineering, Microbiology, and in Chemical and Biomolecular Engineering has been honored with a 2022 Young Investigator Award by the Royal Spanish Society of Chemistry (RSEQ) for his pioneering research efforts to combine the power of machines and biology to help prevent, detect, and treat infectious diseases.

Read the RSEQ’s announcement here.

This story originally appeared in Penn Medicine News’s Awards & Accolades post for April 2022.

 

2022 Graduate Research Fellowships for Bioengineering Students

Congratulations to the two Bioengineering students to receive 2022 National Science Foundation Graduate Research Fellowship Program (NSF GRFP) fellowships. The prestigious NSF GRFP program recognizes and supports outstanding graduate students in NSF-supported fields. The eighteen Penn 2022 honorees were selected from a highly-competitive pool of over 12,000 applications nationwide. Further information about the program can be found on the NSF website.

 Gianna Therese Busch, PhD student, Bioengineering
Gianna is a member of the systems biology lab of Arjun Raj, Professor in Bioengineering and Genetics. Her research focuses on single-cell differences in cancer metabolism and drug resistance.

 

 

 

Shawn Kang, BSE/MSE, Bioengineering (’22)
Shawn conducted research in the BIOLines Lab of Dan Huh, Associate Professor in Bioengineering, where he worked to develop more physiologically relevant models of human health and disease by combining organs-on-a-chip and organoid technology.

 

 

 

The following Bioengineering students also received Honorable Mentions:
Michael Steven DiStefano, PhD student
Rohan Dipak Patel, PhD student
Abraham Joseph Waldman, PhD student

Read the full list of NSF GRFP Honorees on the Grad Center at Penn website.