Biohybrid microrobots locally and actively deliver drug-loaded nanoparticles to inhibit the progression of lung metastasis

Summary

This preclinical research uses motile algae to deliver chemotherapy locally within the lung, where limited drug accumulation can hamper treatment of metastases. The biohybrid construct joins green microalgae to doxorubicin-loaded polymer nanoparticles coated with red-blood-cell membrane. After intratracheal administration, the algae provide autonomous propulsion, carrying the nanoparticle cargo deep into the lungs while continuing to move. Relative to passive drug-loaded particles and free doxorubicin, the microrobots produced faster intrapulmonary distribution, greater tissue accumulation, and longer retention. Controlled release and wider dispersion were intended to increase antimetastatic exposure at the disease site. In a mouse model of melanoma metastasis to the lung, treatment reduced metastatic burden and extended survival compared with the reported control groups. The principal finding is that living propulsion can alter the local distribution and residence of a membrane-coated chemotherapeutic carrier, translating improved delivery into a disease and survival benefit in mice. This supports active pulmonary transport as a strategy for metastatic disease. The abstract does not describe systemic toxicity, lung inflammation, dosing, microrobot clearance, comparison with standard systemic regimens, or whether the approach works in other metastatic tumor types.