Homologous DNA recombination in vivo with the delivery of Cas9 ribonucleoprotein and donor DNA complexed to gold nano particles

Cas9 based therapeutics have the potential to revolutionize the treatment of genetic diseases because of their ability to generate homologous DNA recombination (HDR) and correct DNA mutations. However, viral gene therapy is currently the only delivery technology available for generating HDR in vivo with Cas9, and is challenging to bring into clinical trials because of off-target DNA damage and immunogenicity. In this presentation, I will describe a non-viral Cas9 delivery vehicle, termed CRISPR-Gold, which can induce HDR in vivo by directly delivering Cas9 protein, gRNA, and donor DNA. CRISPR-Gold is composed of gold nanoparticles assembled with the Cas9/gRNA ribonucleoprotein (RNP) complex, donor DNA, and an endosomal disruptive polymer. We have been able to demonstrate that CRISPR-Gold can correct the DNA mutation that causes Duchenne muscular dystrophy (DMD) in mdx mice via HDR, with an efficiency of 5.4% after an intramuscular injection and with minimal levels off-target DNA damage. In addition, we demonstrate that CRISPR-Gold can improve muscle strength and lower tissue fibrosis in mdx mice. CRISPR-Gold is the first example of a DMD therapeutic that can correct the mutated dystrophin protein back to its wild type sequence, and has tremendous potential for treating DMD and other genetic diseases caused by single base pair mutations.

Bio
Dr. Niren Murthy is a professor in the Department of Bioengineering at the University of California at Berkeley. Dr. Murthy received his Ph.D. from the University of Washington in Seattle in Bioengineering in 2001, and then did Postdoctoral research at U.C. Berkeley in Chemistry from 2001-2003. He started his academic career at Georgia Tech in 2003 and in 2012 moved back to U.C. Berkeley. Dr. Murthy’s laboratory is an interdisciplinary laboratory that focuses on the development of new materials for drug delivery and molecular imaging. Murthy laboratory has developed several new biomaterials and imaging agents, such as the maltodextrin based imaging agents, which are focused on improving the treatment and diagnosis of infectious diseases. In addition, Murthy laboratory has developed numerous reagents for detecting radical oxidants, such as the hydrocyanines.

Molecular Engineering and Sciences Seminar Series

This weekly seminar brings together students, faculty and invited guests from various disciplines across campus to explore current trends in molecular engineering and nanotechnology. It is a  forum for active interdisciplinary discussions.  These talks are open to the public and attract a diverse audience of students and faculty.