Gene editing has promised a way to treat some diseases, including inherited genetic disorders, blood conditions and cancer, at their genetic roots. But even as tools such as CRISPR, which allows scientists to alter DNA sequences and modify gene function with high precision, have become increasingly powerful, a practical challenge remains: Many genome editors are too large to fit easily into the delivery vehicles used to carry them into cells.
A gene-editing system must get inside a cell before it can make the desired genetic change, but cell membranes prevent large molecules from simply entering. To overcome this obstacle, researchers can use lipid nanoparticles to deliver editor proteins or messenger RNA, or leverage engineered viruses to deliver the DNA encoding the editor. The larger the editor or its genetic instructions, the more difficult this delivery process can be.
One possible solution to widen the use of gene editors is to make them smaller.
Adeno-associated viruses, or AAVs, are commonly used to deliver gene therapies, but they can carry only a limited amount of genetic material. Compact gene-editing tools could help overcome this constraint by leaving more room for the other components needed to direct and control editing.
