In a groundbreaking leap forward for cancer therapy, researchers at Northwestern University have transformed a decades-old chemotherapy drug into a far more powerful and safer version. The innovative nanoscale treatment kills cancer cells up to 20,000 times more effectively than its predecessor — and does so without harming healthy tissue.
How Researchers Reinvented a Classic Chemotherapy Drug
The Northwestern team focused on 5-fluorouracil (5-Fu), a chemotherapy staple that’s often limited by poor solubility and severe side effects. Traditionally, less than 1% of 5-Fu dissolves in biological fluids, which means most of it never reaches cancer cells effectively — and what does often damages healthy cells.
To overcome these challenges, scientists redesigned 5-Fu at the molecular level, turning it into a spherical nucleic acid (SNA) — a nanoscale structure built from tightly packed DNA strands surrounding a tiny core. This structural transformation dramatically improved how the drug is absorbed by cancer cells, making it both more potent and more precise.
20,000 Times More Effective in Killing Cancer
When tested in animal models of acute myeloid leukemia (AML), the redesigned SNA-based drug penetrated cancer cells 12.5 times more efficiently and destroyed them 20,000 times faster than conventional 5-Fu. Even more remarkably, researchers observed no detectable side effects — a rarity in chemotherapy.
“In animal models, we demonstrated that we can stop tumors in their tracks,” said Chad A. Mirkin, the study’s lead scientist. “If these results carry over to human patients, it could completely transform chemotherapy — offering higher effectiveness with minimal side effects.”
The findings were published in the journal ACS Nano and reported by SciTech Daily.
What Makes Structural Nanomedicine So Revolutionary?
This achievement underscores the power of structural nanomedicine — an emerging scientific field where both the shape and chemical makeup of nanomedicines are designed to control how they behave in the body. By reengineering drugs at the nanoscale, scientists can drastically change how they target and treat disease.
The SNA version of 5-Fu represents a major milestone for this technology, turning a once-toxic and weakly effective drug into a high-precision cancer therapy. Professor Mirkin, who has pioneered SNA technology for years, noted that several SNA-based treatments are already in clinical trials for other conditions.
How the New Drug Targets Cancer Cells — and Spares Healthy Ones
One of the biggest issues with standard chemotherapy is its lack of precision — it attacks both cancerous and healthy cells indiscriminately. The new SNA-based 5-Fu changes that dynamic.
Because myeloid cells naturally absorb the SNA structure through specific surface receptors, the drug selectively enters cancer cells. Once inside, enzymes break down the DNA shell, releasing the active drug directly where it’s needed. This targeted mechanism helps eliminate cancer while protecting surrounding healthy tissue.
Promising Results and the Road Ahead
In mouse studies, the nanodrug nearly eradicated leukemia cells from the blood and spleen while extending survival rates — all without the toxic side effects typical of chemotherapy.
“Current chemotherapeutics kill everything they touch,” Mirkin explained. “Our structural nanomedicine, however, seeks out cancerous myeloid cells and delivers a focused, powerful dose right to the target.”
Following these results, the research team plans to expand testing to larger animal models before progressing to human clinical trials, pending funding and regulatory approval.
If the same outcomes are replicated in humans, this could mark a turning point in cancer treatment — transforming chemotherapy from a harsh, body-wide assault into a targeted, precision-guided therapy that maximizes impact and minimizes harm.