Tuesday , January 18 2022

New technologies based on moths and magnets can help in the treatment of genetic diseases.


New technologies that rely on moth-infectious viruses and nanomagnets can be used to edit defective genes that cause diseases such as sickles, muscular atrophy, and cystic fibrosis.

Rice University biotechnologist Gang Bao combines magnetic nanoparticles with a viral container from a specific species of moth to deliver CRISPR / Cas9 mounts to modify the genes of specific tissues or organs through spatial control.

Because the magnetic field is easy to manipulate and unlike light, it passes easily through the tissues, so Bao and his colleagues want to control the expression of the viral mediator in the target tissue by activating the inactivated virus in the blood if not otherwise.

The results Natural Biotechnology. Naturally, CRISPR / Cas9 records the intruder's DNA to reinforce the microbial immune system. This provides microorganisms with the ability to recognize and attack re-invaders, but scientists are racing CRISPR / Cas9 to repair genetic mutations and manipulate DNA in laboratory experiments.

CRISPR / Cas9 is likely to prevent genetic disease. It is possible that scientists bring genome editing machines to the right cells inside the body. But obstacles remain especially when delivering genetic manipulation payloads with high efficiency.

Bao said he had to edit the cells of his body to treat many diseases. "But efficient control of the genome editing machine in the target tissue of the body with spatial control is still an important challenge," Bao said. "A local injection of a viral vector can leak into other tissues or organs, which can be dangerous."

The vehicle developed by the Bao Group is based on a virus that infects Autographa californica, also known as alfalfa looper from North America. The cylindrical baculovirus vector (BV) carrying the virus load is considered to be up to 60 nanometers in diameter and as large as 200-300 nanometers in length. Bao said researchers are large enough to carry more than 38,000 base pairs of DNA sufficient to supply multiple genetic editing units to target cells.

He was inspired to combine the BV with magnetic nanoparticles from Dr. Rice's postdoctoral researcher and a discussion with Haibao Zhu, a co-author who knew about the virus during his postdoctoral research in Singapore but did not know anything about magnetic nanoparticles until he joined Bao's lab. He said. The Rice team had previously used iron oxide nanoparticles and magnetic fields to open the vein walls to allow large-molecule drugs to pass through them.

"We really did not know if this worked for genetic editing, but we thought it was worth trying once," Bao said.

The researchers use magnetic nanoparticles to activate the BV and deliver the gene editing payload only when needed. To do this, they typically use an immune system protein called C3, which inactivates the baculovirus.

"Combining BV with magnetic nanoparticles can overcome this inactivation by applying a magnetic field." When we deliver it, genetic editing occurs only in a tissue or part of an organism, where we apply a magnetic field. "

Applying a magnetic field allows the transfection of BV, a payload transfer process that introduces GMOs into target cells. The mount is also a DNA encoding the reporter gene and the CRISPR / Cas9 system.

In the test, BV was loaded with green fluorescent protein or firefly luciferase. Magnets were very effective for target transfer of BV cargo in laboratory animals and animals, with brightly shining cells under the microscope.

Bao said that he and other laboratories are working to deliver Adeno-associated virus (AAV) to CRISPR / Cas9, but the therapeutic load capacity of BV is about eight times greater. "However, it is necessary to make BV transduction into target cells more efficiently," he said.

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