Small interfering RNAs (siRNAs) can turn off any specific gene in the genome. As a result, these molecules have tremendous potential as both scientific tools and therapeutics. However, delivering siRNA to the right cells in vivo has remained challenging. Using combinatorial chemical synthesis techniques and high-throughput biological screening methods, Daniel Anderson and co-workers have designed a nanoparticle that delivers siRNA to endothelial cells — cells that line blood and lymphatic vessels — at very low doses. Using this nanoparticle, the researchers turned off five genes at once inside an animal, turned off genes for more than three weeks after one injection, and reduced inflammation, tumour growth and metastasis. The cover image shows blood vessels in mouse adipose tissue stained with two endothelial cell markers, CD31 (blue) and ICAM-2 (magenta).
Cover Art by Aude Thiriot
