Genetically editing cells using CRISPR could be the answer to curing genetic disorders such as sickle cell anemia. But in order for the technology to be available for people in countries like Nigeria — where around a quarter of the population carries the sickle cell trait — the technology will need to become substantially cheaper and less invasive.
That’s where gold nanoparticles come in.
Scientists at the Fred Hutchinson Cancer Research Center are devising an approach that vastly simplifies how CRISPR is applied. Their goal is to create a safe process for gene editing that takes place entirely within the body of a patient.
In order to edit human stem cells using CRISPR today, scientists have to follow a process that involves removing the cells from a patient’s bone marrow, electrocuting those cells, and modifying them with engineered virus particles.
The process gets even more invasive from there. “We actually have to treat these patients with chemotherapy, radiation or other agents in order for these cells that were genetically manipulated to be taken up,” Jennifer Adair, a senior scientist at Fred Hutch, said during a talk at the 2019 GeekWire Summit.
The researchers think they’ve figured out the first step, which is delivering CRISPR to blood stem cells inside the body. They’re doing that using gold nanoparticles that are about a billionth the size of a grain of table salt and able to smuggle in RNA, DNA and a protein.
“We’ve been able to show that not only can we make these, but they passively deliver all of those components to blood stem cells, then we do get genetic editing. And we’ve been able to go on to show that we can correct the sickle cell defect using this approach,” said Adair.
(Robert Hood / Fred Hutch Photo)
The nanoparticles are big enough to carry the CRISPR payload but small enough to infiltrate cell membranes. Gold is a useful medium since it isn’t harmful to humans.
The Fred Hutch team published their work with gold nanoparticles earlier this year in the journal Nature Materials. The system safely edited 10 to 20 percent of the target cells, which the researchers hope will increase as the method is refined.
In an ideal world, clinicians would be able to deliver gene therapy through a syringe, a process that might be accomplished in a single office visit. Adair previously published research on a “gene therapy in a box” concept, a table-top device that could provide gene therapy treatments without the need for expensive medical infrastructure.
“We need to develop technologies that make gene editing simpler, more affordable and more accessible to patients around the world,” Adair said.
