RNA Nanoparticles - How Do We Get Them to the Cells That We Need to Target?

How do we get all of those fantastic macromolecular drugs that we have developed over the years from CRISPR-based genome editing, mRNA therapies, small interfering RNAs, intracellular antibodies? They're all relatively easy to generate, I guess, in the test tube in vitro. But how do we get them to the cells inside the patient's body that we need to target? And my first question is, so we have our new fancy drug in our test tube. What barriers does that drug have to cross before it reaches the cell that weneed to target? Maybe Katie, you want to start? Sure.