A new approach to drug-resistant cancer uses nanoparticles to disable tumor defenses before delivering chemotherapy. The method achieved complete tumor elimination in mice without harming healthy tissue.
How nanoparticles outsmart resistant cancer cells
Cancer cells frequently develop multidrug resistance by producing proteins that expel chemotherapy drugs before they can act. This resistance causes many treatments to fail, leaving doctors to either raise doses—risking severe side effects—or switch to less effective alternatives.
A team led by Professor Eijiro Miyako at Tohoku University created nanoparticles that first release a compound to block these drug-expelling proteins. Once the cancer cells’ defenses are disabled, the nanoparticles deliver the chemotherapy drug doxorubicin.
The method combines this sequential release with photothermal therapy, where near-infrared laser light heats and destroys tumors. In mouse trials, the approach eliminated drug-resistant tumors completely, with all treated mice surviving. No damage to healthy tissue was observed.
From lab success to potential patient impact
Multidrug resistance affects many cancer types, including breast, lung, and ovarian cancers. Existing strategies, such as pairing P-glycoprotein inhibitors with chemotherapy, have had limited success because the drugs are expelled before working.
Miyako compared the problem to a leaky bucket. “You must patch the hole before adding more water,” he said. The nanoparticles first seal the “leak”—the P-gp pump—before delivering the drug.
The particles are made from amino acid-based materials, which may simplify clinical use. Unlike traditional drug combinations, this method ensures chemotherapy reaches its target at the optimal moment, reducing the need for higher doses.
In experiments, the three-part treatment—sequential drug release, photothermal therapy, and tumor targeting—performed better than chemotherapy or photothermal therapy alone. Tumors treated with the full approach disappeared, while those receiving only photothermal therapy shrank temporarily before returning.
The findings, published in the Journal of Controlled Release, suggest the platform could restore chemotherapy’s effectiveness in tumors unresponsive to standard treatments. Human trials are still required, but the results provide a possible solution for patients with limited options.
Miyako described the nanoparticles as promising, highlighting their biocompatible materials. If proven safe and effective in humans, the method could change how resistant cancers are treated—replacing high-dose approaches with precise timing and targeted destruction.
The work involved collaboration between Tohoku University, the Japan Advanced Institute of Science and Technology, and the French National Centre for Scientific Research at the University of Strasbourg.
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