New nanoparticles provide CRISPR gene editing tools in cell with much higher efficiency

MEDFORD / SOMERVILLE, Mbad. (July 12, 2019) – A research collaboration between Tufts University and the Chinese Academy of Sciences led to the development of a greatly improved delivery mechanism for the method of delivery. the CRISPR / Cas9 gene in the liver, according to a study recently published in the journal Advanced Materials. The delivery uses synthetic biodegradable lipid nanoparticles that carry the molecular modification tools in the cell to accurately modify the genetic code of cells with up to 90% efficiency. According to researchers, nanoparticles are one of the most effective CRISPR / Cas9 delivery tools reported to date. They could help overcome the technical barriers that allow genetic modification in a wide range of clinical therapeutic applications.

The CRISPR / Cas9 gene editing system has become a powerful research tool for discovering the function of hundreds of genes. He is currently studying as a therapeutic tool for the treatment of various diseases. However, there are still some technical hurdles to overcome before it can be practical for clinical applications. CRISPR / Cas9 is a large molecular complex containing both a nuclease (Cas9) capable of cutting across both strands of a targeted genomic sequence, and a modified "single-guide" RNA (sgRNA) that badyzes the genome to help the nuclease to find specific sequence to edit. As this is a large molecular complex, it is difficult to bring CRISPR / Cas9 directly into the nucleus of the cell, where it can perform its work. Others have incorporated editing molecules into viruses, polymers and different types of nanoparticles to insert them into the nucleus, but the low transfer efficiency has limited their use and potency for clinical applications.

The lipid nanoparticles described in the study encapsulate the messenger RNA (mRNA) encoding Cas9. Once the content of nanoparticles – including sgRNA – is released into the cell. The cell's protein production machinery takes over and creates Cas9 from the mRNA template, thus completing the gene editing kit. A unique feature of the nanoparticles is synthetic lipids including disulfide bonds in the fatty chain. When the particles enter the cell, the environment within the cell opens the disulfide bond to disbademble the nanoparticles and the contents are quickly and efficiently released into the cell.

"We are just beginning to attend clinical trials on CRISPR therapies in humans," said Qiaobing Xu, co-correspondent author of the study and an badociate professor of biomedical engineering at the University. Tufts. "There are many diseases for which CRISPR therapies could offer new hope – for example sickle cell disease, Duchenne muscular dystrophy, Huntington's disease and even many cancers." We hope this advance will allow us to progress CRISPR an approach effective and practical treatment. "

The researchers applied the new method to mice in an attempt to reduce the presence of a gene encoding PCSK9, the loss of which is badociated with lower LDL cholesterol and a reduced risk of cardiovascular disease. "Lipid nanoparticles are one of the most efficient CRISPR / Cas9 transporters we have seen," said Ming Wang, also a co-correspondent of the study and a professor at the Chinese Academy of Sciences. from the National Molecular Sciences Laboratory in Beijing. "We can actually suppress the expression of PCSK9 in mice with 80% efficiency in the liver, which bodes well for a real promise for therapeutic applications."

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In addition to the authors cited above, the study was directed by Ji Liu, graduate student and first author of the Institute of Chemistry of the Chinese Academy of Sciences, along with co-authors Jin Chang, Ying Jiang, Lanqun Mao, professors of the Chinese Academy of Sciences, and Xiandi Meng, and Tianmeng Sun of the First Hospital and International Science Center of the Future, Jilin University.

This work was partially funded by China's Key National Research and Development Program (2017YFA0208100, 2016YFA0200104) and the National Science Foundation of China (21778056, 21790390, 21790391, 21621062 and 21435007). The National Institutes of Health (UG3 TR002636-01 and R21 EB024041) also provided support. The content engages only the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Liu J, Chang J, Jiang Y, Meng X, Sun T, Mao L, Xu Q * and Wang M. "Rapid and efficient CRISPR / Cas9 genome editing in vivo made possible by lipid and messenger RNA nanoparticles bioréductibles. " Advanced Materials June 19, 2019: e1902575. DOI: 10.1002 / adma 201902575

The Tufts University, located on the campuses of Boston, Medford / Somerville and Grafton, Mbadachusetts, and Talloires, France, is recognized among the leading research universities in the United States. Tufts enjoys a worldwide reputation for academic excellence and student readiness as leaders in a wide range of professions. A growing number of innovative teaching and research initiatives cover all Tufts campuses, and collaboration between professors and students in undergraduate, graduate and professional programs in the schools of Tufts. 39, university is widely encouraged.