Researchers at Northwestern University embedded 5-fluorouracil (5FU) into spherical nucleic acids, converting the drug from a linear to a globular form that improved solubility and biodistribution. In mouse models the nano-formulation selectively targeted myeloid leukemia cells, increased effective potency by about 20,000-fold, and produced tumor regression with improved survival. The team plans to pursue human trials as soon as next year, while emphasizing that safety and efficacy must be confirmed in clinical studies.
Nanotech Remodels Chemo Drug to Target Leukemia — ~20,000× Potency Gain in Mice, Human Trials Planned
Researchers at Northwestern University embedded 5-fluorouracil (5FU) into spherical nucleic acids, converting the drug from a linear to a globular form that improved solubility and biodistribution. In mouse models the nano-formulation selectively targeted myeloid leukemia cells, increased effective potency by about 20,000-fold, and produced tumor regression with improved survival. The team plans to pursue human trials as soon as next year, while emphasizing that safety and efficacy must be confirmed in clinical studies.
09:11, 07.11.2025Health
Nanotech retools chemotherapy to target leukemia in mice
CHICAGO — Researchers at Northwestern University have redesigned the chemotherapy drug 5-fluorouracil (5FU) at the nanoscale, embedding it into spherical nucleic acids (SNAs) to make the therapy far more soluble and selectively taken up by leukemia cells in animal models. The reformulation produced dramatic results in mice and could move into human trials as soon as next year.
How the nanoscale change works
Chad A. Mirkin, PhD, director of the International Institute for Nanotechnology at Northwestern, explained that the team combined existing technologies to create a new class of medicines. Instead of delivering 5FU as free linear molecules, the researchers incorporated the drug into the nucleic acid strands that form a tiny, globular SNA. Restructuring the molecule from a linear to a spherical form alters its solubility, biodistribution, and cell uptake.
Mirkin: Restructuring on the nanoscale changes where the drug goes, how soluble it is, what it can enter, and ultimately what it can kill.
Results in animal models
The SNAs are rapidly taken up by myeloid cells, a feature the team exploited to target acute myeloid leukemia (AML). In mouse studies the nano-formulated 5FU largely avoided healthy cells, selectively reached leukemia cells, penetrated them, and triggered tumor regression. The investigators report an increase in effective potency of roughly 20,000-fold compared with the original formulation in these models, and treated animals showed substantial tumor shrinkage and improved survival.
Kuo: We are essentially tricking cancer cells with a nanoscale Trojan horse that delivers the drug where it is needed.
Next steps and caveats
Mirkin cautioned that these are early results from preclinical studies. While the findings are encouraging and support advancing the approach into clinical testing, safety and efficacy in humans must be established in careful trials. The lab already has several other nano-structured therapies moving through clinical trials, including cancer vaccine platforms, and expects to pursue patient studies of the retooled 5FU next year if regulatory and trial approvals proceed.
Bottom line: Repackaging a decades-old chemotherapy agent into a spherical nucleic acid dramatically changed its behavior in mice, improving targeting and potency against leukemia cells. Further studies will determine whether the approach translates safely and effectively to people.