Seminar: Chemical Design of Synthetic Nanoparticle Carriers for CRISPR/Cas Gene Editing and mRNA-mediated Protein Replacement Therapy

October 28, 2019 @ 1:00 pm – 2:00 pm
Donnelly Centre, Red Seminar Room (2nd Floor)
160 College Street

Dr. Daniel Siegwart
Department of Biochemistry
University of Texas Southwestern Medical Center

Structure‐guided, rational optimization of nanoparticle carriers for delivery of long RNAs to achieve CRISPR/Cas gene editing and mRNA-mediated protein replacement will be described. CRISPR/Cas is a revolutionary gene editing technology with wide-ranging utility. We will present and report the development of zwitterionic amino lipids (ZALs) that are uniquely able to deliver long RNAs (Cas9 mRNA and targeted sgRNA) from ZAL nanoparticles (ZNPs) to enable gene editing. ZALs were synthesized using high efficiency ring-opening and addition reactions, providing access to a library of unique charge unbalanced lipids. Intravenous co-delivery of Cas9 mRNA and sgLoxP induced expression of floxed tdTomato in the liver, kidneys, and lungs of genetically engineered mice. Correction of a mutation causing Duchenne muscular dystrophy (DMD) via an exon skipping approach will be highlighted as a functional application of CRISPR/Cas in muscle. The effectiveness of ZNPs for delivery of long RNAs provides a chemical guide for the rational design of future carriers. Such insights allowed reengineering of dendrimer-based lipid nanoparticles (DLNPs) for mRNA-based protein replacement therapy, where mDLNPs effectively delivered fumarylacetoacetate hydrolase (FAH) mRNA that normalized liver function and significantly extended survival in a difficult‐to‐treat Hepatorenal Tyrosinemia Type I (HT‐1) mouse model. The development of gene editing using synthetic nanoparticles is a promising step towards improving the safety, efficacy, and utility of CRISPR/Cas.


Dr. Daniel J. Siegwart is an Associate Professor in the Department of Biochemistry at UT Southwestern Medical Center. He received a B.S. in Biochemistry from Lehigh University (2003), and a Ph.D. in Chemistry from Carnegie Mellon University (2008) with University Professor Krzysztof Matyjaszewski. He also studied as a Research Fellow at the University of Tokyo with Professor Kazunori Kataoka (2006). He then completed a Postdoctoral Fellowship at MIT with Institute Professor Robert Langer (2008-2012). The Siegwart Lab aims to discover and define the critical physical and chemical properties of synthetic carriers required for therapeutic delivery of small (e.g. ~22 base pair miRNA) to large (e.g. ~5,000 nucleotide mRNA) RNAs. Their research is grounded in chemical design and takes advantage of the unique opportunities for collaborative research at UT Southwestern.

Hosted by Dr. Molly Shoichet
Snacks and Refreshments will be served