Imagine a medicine that stops seizures at their source, switches off instructions that keep a cancerous tumor growing and prevents Alzheimer's from stealing memories and wreaking havoc on the brain.

The basis for such treatment is already here. Known as oligonucleotides [pronounced ah-lee-go-noo-klee-oh-tides], these drugs are made from small bits of DNA or RNA—the blueprint cells use to make proteins.

While most drugs act on the finished products, oligonucleotides cut to the chase and intervene upstream, before the proteins have a chance to roll off the cellular assembly line. They can block production of harmful proteins or help cells make ones they need by tinkering with the instructions.

There's one big catch, however.

"Knowing what gene to target is only part of the problem," said Northeastern chemistry and chemical biology professor Ke Zhang, who is developing ways to make oligonucleotides more effective. "The other part is getting the drug to the right place in the right cells."

In the Journal of the American Chemical Society, Zhang and his colleagues present research that suggests a new way to get oligonucleotides into body tissues. The molecular structures his lab is developing shuttle the drugs to their destinations.

They resemble tiny bottlebrushes, with bristles that protect the medicines attached to them. The secret to their success lies in a short sequence of chemical building blocks incorporated into their structure. It acts as a set of delivery instructions to steer the medicine toward particular tissues.

By helping genetic medicines reach their target, this approach could unlock their potential to tackle diseases that are currently untreatable...