2021 MIPS Molecular Imaging Seminar Series

Cell surface glycans constitute a rich biomolecular dataset that drives both normal and pathological processes.  Their “readers” are glycan-binding receptors that can engage in cell-cell interactions and cell signaling.  Our research focuses on mechanistic studies of glycan/receptor biology and applications of this knowledge to new therapeutic strategies.  Our recent efforts center on pathogenic glycans in the tumor microenvironment and new therapeutic modalities based on the concept of targeted degradation.

In many ways, manufacturing processes define what’s possible in society.  Central to our interests in the DeSimone laboratory are opportunities to make things using cutting-edge fabrication technologies that can improve human health.  This lecture will describe advances in nano- / micro-fabrication and 3D printing technologies that we have made and employed toward this end.  Using novel perfluoropolyether materials synthesized in our lab in 2004, we invented the Particle Replication in Non-wetting Templates (PRINT) technology, a high-resolution imprint lithography-based process to fabricate nano- and micro-particles with precise and independent control over particle parameters (e.g. size, shape, modulus, composition, charge, surface chemistry).  PRINT brought the precision and uniformity associated with computer industry manufacturing technologies to medicine, resulting in the launch of Liquidia Technologies (NASDAQ: LQDA) and opening new research paths, including to elucidate the influence of specific particle parameters in biological systems (Proc. Natl. Acad. Sci. USA 2008), and to reveal insights to inform the design of vaccines (J. Control. Release 2018), targeted therapeutics (Nano Letters 2015), and even synthetic blood (PNAS 2011).  In 2015, we reported the invention of the Continuous Liquid Interface Production (CLIP) 3D printing technology (Science 2015), which overcame major fundamental limitations in polymer 3D printing—slowness, a very limited range of materials, and an inability to create parts with the mechanical and thermal properties needed for widespread, durable utility.  By rethinking the physics and chemistry of 3D printing, we created CLIP to eliminate layer-by-layer fabrication altogether.  A rapid, continuous process, CLIP generates production-grade parts and is now transforming how products are manufactured in industries including automotive, footwear, and medicine.  For example, to help address shortages, CLIP recently enabled a new nasopharyngeal swab for COVID-19 diagnostic testing to go from concept to market in just 20 days, followed by a 400-patient clinical trial at Stanford.  Academic laboratories are also using CLIP to pursue new medical device possibilities, including geometrically complex IVRs to optimize drug delivery and implantable chemotherapy absorbers to limit toxic side effects.  Vast opportunities exist to use CLIP to pursue next-generation medical devices and prostheses.  Moreover, CLIP can improve current approaches; for example, the fabrication of an iontophoretic device we invented several years ago (Sci. Transl. Med. 2015) to drive chemotherapeutics directly into hard-to-reach solid tumors is now being optimized for clinical trials with CLIP.  New design opportunities also exist in early detection, for example to improve specimen collection, device performance (e.g. microfluidics, cell sorting, supporting growth and studies with human organoids), and imaging (e.g. PET detectors, ultrasound transducers).  Here at Stanford, we are pursuing new 3D printing advances, including software treatment planning for digital therapeutic devices in pediatric medicine, as well as the design of a high-resolution printer capable of single-digit micron resolution to advance microneedle designs as a potent delivery platform for vaccines.  The impact of our work on human health ultimately relies on our ability to enable a convergent research program to take shape that allows for new connections to be made among traditionally disparate disciplines and concepts, and to ensure that we maintain a consistent focus on the translational potential of our discoveries and advances.

Inspired by Dr Sam Gambhir, MIPS, Canary Center, and Stanford CCNE have pursued in vivo imaging and in vitro diagnostic tests for cancer therapeutic response or early detection, respectively, over the last 15+ years. Here I present two successful examples based on circulating tumor DNA (ctDNA) targets in plasma, complementary to imaging modalities such as CT and Ultrasound.  

We have developed a simple yet highly sensitive assay for the detection of actionable mutational targets such as Epidermal Growth Factor Receptor (EGFR) and Kirsten rat sarcoma oncogene (KRAS) mutations in the plasma ctDNA from non-small cell lung cancer (NSCLC) patients using giant magnetoresistive (GMR) nanosensors. Our assay achieves lower limits of detection compared to standard fluorescent PCR based assays, and comparable performance to digital PCR methods. In 30 patients with metastatic disease and known EGFR mutation status at diagnosis, our assay achieved 87.5% sensitivity for Exon19 deletion and 90% sensitivity for L858R mutation while retaining 100% specificity; additionally, our assay detected secondary T790M mutation resistance with 96.3% specificity while retaining 100% sensitivity. We re-sampled 13 patients undergoing tyrosine kinase inhibitor (TKI) therapy 2 weeks after initiation to assess response, our GMR assay was 100% accurate in correlation with longitudinal clinical outcome, and the responders identified by the GMR assay had significantly improved progression free survival (PFS) compared to the non-responders. The GMR assay is low cost, rapid, and portable, making it ideal for detecting actionable mutations at diagnosis and non-invasively monitoring treatment response in the clinic.

On another front, we have also developed a highly sensitive and multiplexed assay for the detection of methylated ctDNA targets in plasma samples. Current diagnostic tests for liver cancer in at-risk patients are cumbersome, costly and inaccurate, resulting in a need for accurate blood-based tests. By devising a Layered Analysis of Methylated Biomarkers (LAMB) from the relevant big data, we have discovered a set of DNA targets in the blood that accurately detects liver cancer in these at-risk patients. This set of methylated targets was found by analyzing the genetic information of 3411 liver cancer patients and 1722 healthy people. Our results could lead to clinical adoption of liquid biopsy tests for liver cancer surveillance in high-risk populations and the development of blood tests for other cancers.

ABSTRACT
We present our research controlling light at the nanoscale for infectious disease diagnostics, including detecting bacteria at low concentration, sensing COVID gene sequences, and visualizing in-vivo inter-cellular forces. First, we combine Raman spectroscopy and deep learning to accurately classify bacteria by both species and antibiotic resistance in a single step. We design a convolutional neural network (CNN) for spectral data and train it to identify 30 of the most common bacterial strains from single-cell Raman spectra, achieving antibiotic treatment identification accuracies exceeding 99% and species identification accuracies similar to leading mass spectrometry identification techniques. Our combined Raman-CNN system represents a proof-of-concept for rapid, culture-free identification of bacterial isolates and antibiotic resistance. Second, we describe resonant nanophotonic surfaces, known as “metasurfaces” that enable multiplexed detection of SARS-CoV-2 gene sequences. Our metasurfaces utilize guided mode resonances excited in high refractive index nanostructures. The high quality factor modes produce a large amplification of the electromagnetic field near the nanostructures that increase the response to targeted binding of nucleic acids; simultaneously, the optical signal is beam-steered for multiplexed detection. We describe how this platform can be manufactured at scale for portable, low-cost assays. Finally, we introduce a new class of in vivo optical probes to monitor biological forces with high spatial resolution. Our design is based on upconverting nanoparticles that, when excited in the near-infrared, emit light of a different color and intensity in response to nano-to-microNewton forces. The nanoparticles are sub-30nm in size, do not bleach or photoblink, and can enable deep tissue imaging with minimal tissue autofluorescence. We present the design, synthesis, and characterization of these nanoparticles both in vitro and in vivo, focusing on the forces generated by the roundworm C. elegans as it feeds and digests its bacterial food.

ABOUT
Jennifer Dionne is the Senior Associate Vice Provost of Research Platforms/Shared Facilities and an associate professor of Materials Science and Engineering and, by courtesy, of Radiology at Stanford. She is also an Associate Editor of Nano Letters, director of the DOE-funded Photonics at Thermodynamic Limits Energy Frontier Research Center, and an affiliate faculty of the Wu Tsai Neurosciences Institute, the Institute for Immunity, Transplantation, and Infection, and Bio-X. Jen received her B.S. degrees in Physics and Systems Science and Mathematics from Washington University in St. Louis, her Ph. D. in Applied Physics at the California Institute of Technology in 2009, and her postdoctoral training in Chemistry at Berkeley. Her research develops nanophotonic methods to observe and control chemical and biological processes as they unfold with nanometer scale resolution, emphasizing critical challenges in global health and sustainability. Her work has been recognized with the Alan T. Waterman Award, a NIH Director’s New Innovator Award, a Moore Inventor Fellowship, the Materials Research Society Young Investigator Award, and the Presidential Early Career Award for Scientists and Engineers, and was featured on Oprah’s list of “50 Things that will make you say ‘Wow’!”. Beyond the lab, Jen enjoys exploring the intersection of art and science, long-distance cycling, and reliving her childhood with her two young sons.

Jubilant Biosys, an integrated contract research organization in India with business offices in Asia and North America, is a leading collaborator for biotechnology and pharmaceutical companies, with in-depth expertise in discovery informatics, medicinal chemistry, structural biology, and in vitro pharmacology services. Jubilant Biosys provides comprehensive drug discovery services and contract research services, from target discovery to candidate selection and with flexible business models (FFS, FTE and risk shared). This seminar will showcase case studies from recent Stanford projects and a discussion of future opportunities.

SCHEDULE
9:00-9:15 AM, PT – David Anders – Stanford Radiology projects
9:15-9:30 AM, PT – Saurabh Kapure – Introduction to Jubilant Biosys, Scale-up and GMP manufacturing
9:30-9:40 AM, PT – Jay Sheth – How Jubilant Biosys works with academic partners: examples and case-studies
9:40-10:00 AM, PT – Moderated by Jason Thanh Lee – Discussion

ABSTRACT
In recent years, prostate cancer treatment has increasingly focused on selecting patients who are most likely to benefit and reducing harms from treatment. This has been seen both in adoption of active surveillance for men with low-risk prostate cancer and emergence of image-guided focal ablative therapy. While focal therapy causes fewer sexual and urinary side effects than conventional prostate cancer treatments, many questions remain about proper patient selection, treatment planning, and follow up care.

Improvements in prostate MRI performance and interpretation have paved the way for adoption of focal therapy. However, clinical challenges remain in prostate cancer imaging. This talk will describe prostate cancer focal therapy, discuss patient selection, and highlight the research efforts of my group to improve MRI interpretation to guide biopsy and improve focal therapy performance.

ABOUT
Geoffrey Sonn, MD is a urologic oncologist who specializes in treating patients with prostate and kidney cancer. He has a particular interest in cancer imaging, MRI-Ultrasound fusion targeted prostate biopsy, prostate cancer focal therapy, and robotic surgery for prostate and kidney cancer. He is the principal investigator of the first clinical trial in Northern California to use MRI-guided focused ultrasound to treat prostate cancer. The goal of this trial is to treat prostate cancer with fewer side effects than surgery or radiation.

Dr. Sonn was born in Washington State and lived there until leaving for college at Georgetown. After graduating magna cum laude at Georgetown he returned to the West Coast for medical school at UCLA. Following medical school, Dr. Sonn completed a 6-year urology residency at Stanford where he developed particular interests in the clinical care of patients with urologic cancers and research in cancer imaging. Dr. Sonn completed a 2-year urologic oncology fellowship at UCLA. Since completing his fellowship, Dr. Sonn has been at Stanford as an assistant professor in urology. Dr. Sonn’s research is devoted to developing new cancer imaging techniques, applying artificial intelligence to find cancers on medical images, and applying new methods to treat prostate cancer with fewer side effects.

Bio: Dr. Bogyo is a Professor of Pathology and Microbiology and Immunology at Stanford University. He received his bachelor’s degree in Chemistry from Bates College in 1993 and a doctorate in Chemistry from Massachusetts Institute of Technology in 1997. Dr. Bogyo established an independent scientific career as a Faculty Fellow at the University of California, San Francisco, where he supervised a small laboratory of post-doctoral fellows and students. In 2001, Dr. Bogyo was hired to establish and direct the Chemical Proteomics Department at Celera Genomics focused on applying small molecule probes to the field of drug discovery. Dr. Bogyo then joined the Department of Pathology at Stanford University in July 2003 and was promoted to Associate Professor in 2009 and to full professor in 2013. His laboratory works on the development of new chemical probe technologies that are applied to study the role of proteases in complex biological pathways associated with human disease. Dr. Bogyo has published over 250 primary research publications and currently serves on the Editorial Board of several prominent research journals. He was the President of the International Proteolysis Society from 2007-2009 and chair of the Gordon Research Conference on Proteolytic Enzymes and Their Inhibitors in 2018 and the Imaging in 2020 meeting in 2016. Dr. Bogyo is also a member of Stanford’s Comprehensive Cancer Center, the Molecular Imaging Program at Stanford (MIPS) and is a consultant for several biotechnology and pharmaceutical companies in the Bay Area. He is the recipient of numerous awards including the Searle Scholar Award, The Terman Fellowship and the Burroughs Wellcome Investigators in Pathogenesis award. He is the co-founder of Akrotome Imaging, a small start up company developing imaging contrast agents for detection of surgical margins.

Abstract: Hydrolases are enzymes (i.e. proteases, esterases, lipases) that often play pathogenic roles in many common human diseases such as cancer, asthma, arthritis, atherosclerosis and infection by pathogens. Therefore, tools that allow dynamic monitoring of their activity can be used as diagnostic agents, as imaging contrast agents and for the identification of novel enzymes as drug leads. In this presentation, I will describe our efforts to design and build small molecule probes that can be used to identify, inhibit and image various hydrolase targets in models of cancer and infectious disease. This will include recent advances in protease activated fluorescent probes for real-time visualization of tumors during surgery as well our efforts to identify several new classes of serine hydrolases in pathogenic and commensal bacteria. We believe many of these enzymes will represent valuable imaging and therapy targets that can be used to visualize and disrupt various aspects of colonization and community formation inside a host.