“One of the heroes of this story is the nanoparticle,” said Anderson, professor of chemical engineering and of health sciences and technology at the MIT Koch Institute for Integrative Cancer Research.
“Encapsulating RNA in a package that can travel through the bloodstream and reach target cells is quite a challenge,” he explained. “Endocytosis is how it gets into the cell. Then it has to escape the endosome and release its payload. Decades of work have gone into this. It isn’t easy.”
Years of experiments on animal models have shown that injected nanoparticles usually end up in the organs that filter blood—liver, spleen, bone marrow and kidney.
But, as Anderson pointed out, “RNA or DNA is simply not a great drug. It does not cross cellular membranes. We need expression of these constructs to get function.”
https://nihrecord.nih.gov/2020/09/04/anderson-explains-role-nanoparticles-vaccines