A team of researchers from the University of California and the University of Tokyo has found a way to use the CRISPR gene editing technique that does not rely on a virus for delivery.
In their paper published in the journal Nature Biomedical Engineering, the group describes the new technique, how well it works and improvements that need to be made to make it a viable gene editing tool.
The team has named the new technique CRISPR-Gold, because a gold nanoparticle was used to deliver the gene editing molecules instead of a virus. The new package was created by modifying a bit of DNA to cause it to stick to a gold nanoparticle and then a Cas9 protein and also an RNA guide. The molecules then set to work-the Cas9 cut the target DNA strand, the guide RNA showed what needed to be done and a DNA strand was placed where a mutation had existed. Nanoparticle delivery of Cas9 ribonucleoprotein and donor DNA in vivo induces homology-directed DNA repair, Nature Biomedical Engineering.
It is challenging to develop homology-directed repair-based therapeutics because they require the simultaneous in vivo delivery of Cas9 protein, guide RNA and donor DNA. Here, we demonstrate that a delivery vehicle composed of gold nanoparticles conjugated to DNA and complexed with cationic endosomal disruptive polymers can deliver Cas9 ribonucleoprotein and donor DNA into a wide variety of cell types and efficiently correct the DNA mutation that causes Duchenne muscular dystrophy in mice via local injection, with minimal off-target DNA damage.