Researchers at Northwestern University have completely reimagined a classic chemotherapy drug using nanotechnology, transforming a weak, poorly soluble compound into a precision cancer therapy that is up to 20,000 times more effective at destroying cancer cells. The scientists created the drug entirely from scratch as a spherical nucleic acid, a nanoscale structure that incorporates the medication into DNA strands surrounding tiny spheres, which dramatically improves how the body absorbs and uses it. Traditional chemotherapy drug 5 fluorouracil dissolves so poorly that less than one percent of it works in many biological fluids, causing it to clump in solid form that the body cannot absorb efficiently while also attacking healthy tissue and causing terrible side effects like nausea, fatigue, and even heart failure. When tested in a small animal model of acute myeloid leukemia, an aggressive and hard to treat blood cancer, the redesigned version entered leukemia cells 12.5 times more efficiently, destroyed them up to 20,000 times more effectively, and slowed cancer progression by a factor of 59.
The breakthrough happened because the structural redesign changed how the drug interacted with cancer cells, allowing myeloid cells to easily recognize and absorb the spherical nucleic acid form before enzymes broke down the DNA shell to release drug molecules that killed the cancer from within. In mouse experiments, the therapy eliminated leukemia cells to near completion in the blood and spleen, significantly extended survival, and left healthy tissues completely unharmed because it selectively targeted only the cancer cells. Today’s chemotherapeutics kill everything they encounter including healthy cells, but this structural nanomedicine preferentially seeks out myeloid cells and delivers a higher, more focused dose exactly where it’s needed instead of overwhelming the whole body. With seven spherical nucleic acid based therapies already in clinical trials, this approach could pave the way for advanced vaccines and new treatments for cancer, infectious diseases, neurodegenerative disorders, and autoimmune conditions.
