Researchers at the Fred Hutchinson Cancer Research Center are using gold nanoparticles to improve CRISPR gene editing.

Text: While CRISPR-Cas9 gene editing is widely used to alter genetic material, it has proven somewhat challenging to deliver into some cells. Some approaches being investigated to overcome this problem have included shocking the cells using viruses as delivery agents. However, the former can result in cell death, while the latter can result in off-target side effects.

Researchers at the Fred Hutchinson Cancer Research Center have developed (https://www.fiercebiotech.com/research/fred-hutch-team-uses-gold-nanoparticles-to-improve-crispr-gene-editing?mkt_tok=eyJpIjoiTWpZM01tTm1aR1V6TXpBMCIsInQiOiJ0XC9aY2dXZXo3Mk1ZOTE5QjdsVEd0YVlpR2lcLzVsSW82cHJ2cXZzOGV0NndLbVwvb2x1dWNCS0JOSitmU1ZGS3RUV3dPU3U4TWhmcnpYVDh3V1lCRDlIMkVLUk5sNSszZnFDeldJK2MxXC9uSlRKVUpLVG1EblJ0SFwvUkdnRWlOWFdWIn0%3D&mrkid=14621160) a promising alternative solution. They have placed the CRISPR components onto engineered gold nanoparticles that are designed to cross the cell membrane, avoid cell organelles and enter the cell nucleus.

The use of gold nanoparticles is attractive because they readily adhere to different types of molecules. The researchers prepared 19 nm–wide nanoparticles that are sufficiently large to hold all of the CRISPR components but small enough to pass through cell walls.

Loaded gold nanoparticles containing four CRISPR components (including the Cas12a, rather than the Cas9, enzyme for DNA cutting) were then delivered to blood stem cells to disrupt the gene CCR5 to make cells resistant to HIV or to create a gene mutation that can protect against blood disorders, including sickle cell disease. In these experiments, successful editing of 20% and 10% of the targeted cells were observed, respectively, with no toxic side effects. Notably, edited cells were located in the animals’ spleens and thymi, as well as in their bone marrow, suggesting that dividing blood cells delivered the edited genetic material throughout the body without the need for a second treatment.

The scientists are currently working on improving the effectiveness of their approach, with a goal of achieving the editing of 50% or more of targeted cells.

Separately, the University of California, Berkeley spinoff GenEdit is developing gold-based CRISPR technology for the treatment of Duchenne muscular dystrophy. In this case, the mutated dystrophin gene has been corrected in mouse models by injecting their CRISPR-Gold system into muscles.