A group of scientists at Fred Hutchinson Cancer Research Center has shed more light towards making gene therapy more accessible by simplifying the way gene-editing instructions are delivered to cells. The scientists used a gold nanoparticle instead of an inactivated virus; they safely delivered gene-editing tools in lab models of HIV and inherited blood disorders. They published their results in Nature Materials.
It is the first time scientists used a gold nanoparticle loaded with CRISPR to edit genes in a rare but powerful subset of blood stem cells, the source of all blood cells. The CRISPR-carrying gold nanoparticle led to successful gene editing in blood stem cells with no toxic effects.
An assistant member of the Clinical Research Division at Fred Hutch and the senior author of the study, Dr. Jennifer Adair, said that as gene therapies make their way through clinical trials and become available to patients, scientists need a more practical approach. Dr. Adair wanted to find something simpler, something that would passively deliver gene editing to blood stem cells.
There are still challenges even though CRISPR has made it faster and easier to precisely deliver genetic modifications to the genome. Getting cells to accept CRISPR gene-editing tools involves a small electric shock that can damage and even kill the cells. And if precise gene edits are required, then additional molecules must be engineered to deliver which adds to cost and time.
A promising alternative is gold nanoparticles due to the surface of these tiny spheres (around 1 billion the size of a grain of table salt) allows other molecules to stick to them and stay adhered easily.
A postdoctoral researcher at Fred Hutch who has worked with gold nanoparticles for drug and gene delivery for seven years, Dr. Reza Shahbazi said that they engineered the gold nanoparticles to cross the cell membrane quickly, dodge cell organelles that seek to destroy them and go right to the cell nucleus to edit genes.
Shahbazi made the gold particles from laboratory-grade gold that is purified and comes as a liquid in a small lab bottle. He mixed the purified gold into a solution that causes the individual gold ions to form tiny particles, which the researchers then measured for size. They discovered that particular dimension - 19 nanometers wide - was the best for being big and sticky enough to add gene-editing materials to the surface of the particles, while still being small enough for cells to absorb them.
