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).

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.

 

New Grant Aims to Broaden Participation in Cutting-Edge Materials Research

University of Puerto Rico’s Edgardo Sánchez (left) and Penn graduate Zhiwei Liao working in the lab of Daeyeon Lee. Via the Advancing Device Innovation through Inclusive Research and Education program, researchers from Penn and the University of Puerto Rico will continue their materials science collaboration while supporting STEM career pathways for underrepresented groups. (Image credit: Felice Macera).

The National Science Foundation (NSF) has awarded grants to eight research teams to support partnerships that will increase diversity in cutting-edge materials research, education, and career development. One of those teams is Penn’s Laboratory for Research on the Structure of Matter (LRSM) and the University of Puerto Rico (UPR), whose long-running collaboration has now received an additional six years of support.

With the goal of supporting partnerships between minority-serving educational institutions and leading materials science research centers, NSF’s Partnership for Research & Education in Materials (PREM) program funds innovative research programs and provides institutional support to increase recruitment, retention, and graduation by underrepresented groups as well as providing underserved communities access to materials research and education.

‘Research at the frontier’

With this PREM award, known as the Advancing Device Innovation through Inclusive Research and Education (ADIIR) program, researchers from Penn and UPR’s Humacao and Cayey campuses will conduct research on the properties of novel carbon-based materials with unique properties, and will study the effects of surface modification in new classes of sensors, detectors, and purification devices.

Thanks to this collaboration of more than 20 years, both institutions have made significant scientific and educational progress aided by biannual symposia and regular pre-pandemic travel between both institutions before the pandemic, resulting in a rich portfolio of publications, conference presentations, patents, students trained, and outreach programs.

“Together we have been publishing good papers that have impact, and we’ve really cultivated a culture of collaboration and friendship between our institutions,” says Penn’s Arjun Yodh, former director of the LRSM. “Our goal is to carry out research at the frontier and, in the process, nurture promising students from Puerto Rico and Penn.”

Ivan Dmochowski, a chemistry professor at Penn who has been involved with PREM for several years, says that this program has helped his group connect with experts in Puerto Rico whose skills complement his group’s interests in protein engineering. Dmochowski has also hosted UPR faculty members and students in his lab and also travelled to Puerto Rico before the pandemic to participate in research symposia, seminars, and outreach events.

“I’ve had students who have benefitted from being a co-author on a paper or having a chance to mentor students, and the faculty we’ve interacted with are exceptional,” Dmochowski says. “There’s a lot of benefit for both me and my students, and I’ve enjoyed our interactions both personally and scientifically.”

Penn’s Daeyeon Lee, a chemical and biomolecular engineering professor who has been involved with PREM for several years, regularly hosts students and faculty from UPR while working on nanocarbon-based composite films for sensor applications. The success of this collaboration relies on unique materials made by researchers at UPR combined with a method for processing them into composite structures developed in Lee’s lab.

“What I really admire about people at PREM, both faculty and students, is their passion,” says Lee. “I think that’s had a really positive impact on my students and postdocs who got to interact with them because they got to see the passion that the students brought.”

Read the full story in Penn Today.

Daeyeon Lee is a professor and the Evan C Thompson Term Chair for Excellence in Teaching in the Department of Chemical and Biomolecular Engineering and a member of the Bioengineering Graduate Group in Penn’s School of Engineering and Applied Science.

Arjun Yodh is the James M. Skinner Professor of Science in the Department of Physics & Astronomy in Penn’s School of Arts & Sciences and a member of the Bioengineering Graduate Group in Penn’s School of Engineering and Applied Science.

Manuela Raimondi Appointed Visiting Professor in Bioengineering

Manuela Raimondi, PhD

Manuela Teresa Raimondi was appointed Visiting Professor in Bioengineering in the Associated Faculty of the School of Engineering and Applied Science for the 2020-2021 academic year. Raimondi received her Ph.D. in Bioengineering in 2000 from Politecnico di Milano, Italy. She is currently a Full Professor of Bioengineering at Politecnico di Milano in the Department of Chemistry, Materials and Chemical Engineering “G. Natta”, where she teaches the course “Technologies for Regenerative Medicine” in the Biomedical Engineering graduate program.

Raimondi is the founder and Director of the Mechanobiology Lab and of the Interdepartmental Live Cell Imaging lab. She has pioneered the development of cutting edge tools for cell modelling, ranging from micro-engineered stem cell niches, to miniaturized windows for in vivo intravital imaging, to microfluidic culture systems to engineer tissue-equivalents and organoids for cell modelling and drug discovery. Her platforms are currently commercialized by her start-up, MOAB srl. Her research is funded by the European Research Council (ERC), by The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), by the European Commission, and by the European Space Agency.

“Getting to Penn was quite the challenge with the various travel restrictions and the pandemic, but I am used to overcoming adverse odds and I am really excited to be here now,” says Dr. Raimondi. “In this challenging time, when many new barriers are coming up, I think building bridges and new scientific collaborations is even more important. I very much look forward to being part of the Penn research community.”

Dr. Raimondi with host Riccardo Gottardi, PhD on Smith Walk

During her sabbatical at Penn, Raimondi is investigating her hypothesis that stem cells pluripotency reprogramming can be guided by mechanical cues. Over the past five years, she has cultured many different stem cell types in the “Nichoids,” the synthetic stem cell niche she developed, and gathered robust evidence on how physical constraints at the microscale level upregulate pluripotency. Raimondi is hosted in the Bioengineering and Biomaterials Lab of Riccardo Gottardi, Assistant Professor in Bioengineering and in Pediatrics at the Perelman School of Medicine, where she is helping to refine human stem cell sources that could be minimally manipulated for translational tissue engineering for a safe and effective use in regenerative therapies, as a key issue for clinical translation is the maintenance or enhancement of multipotency during cell expansion without exogenous agents or genetic modification.

“Dr. Raimondi is a trailblazer in Italy in regenerative medicine who has introduced many new concepts in a sometimes musty academic environment and has shattered a number of glass ceilings,” says Dr. Gottardi. “I think her sabbatical at Penn is a great opportunity for her and for the Penn community to build new and exciting trans-Atlantic collaborations.”