Injectable Disease-Fighting Nanorobots to Improve Precision Cancer Therapy

Cancer therapy, in particular, is limited by poor drug targeting, shallow tumor penetration, and heavy reliance on passive diffusion. These challenges reduce treatment efficacy and increase side effects. A new study now demonstrates an injectable nanorobot that can actively navigate the bloodstream, sense tumor-specific signals, and precisely accumulate within cancer tissue.

Researchers at Wuhan University of Technology (Wuhan, China) have designed enzyme-powered “Janus” nanorobots by integrating two enzymes with distinct roles onto opposite hemispheres of gold nanoparticles. Urease provides propulsion by converting endogenous urea in blood and tumors into mechanical motion, while catalase enables directional control by sensing hydrogen peroxide gradients common in tumor microenvironments. This dual-enzyme design decouples movement and steering, allowing ultrasensitive chemotaxis toward tumor-associated biochemical signals.

The nanorobots were tested in tumor-bearing mouse models following intravenous injection. Compared with passively diffusing nanoparticles, the enzyme-powered nanorobots showed 209-fold higher tumor targeting, more than tenfold deeper tumor penetration, and 1,970-fold greater cellular internalization. The findings, published in National Science Review, show that when loaded with anticancer drugs, the actively navigating nanorobots enhanced tumor suppression by approximately 49 times relative to passive drug carriers.

The propulsion-enhanced chemotaxis strategy is adaptable by changing enzyme combinations, making it applicable beyond cancer therapy. The approach could be extended to diseases marked by localized biochemical gradients, including inflammation and infection. To support clinical translation, the researchers have launched a dedicated company to advance injectable nanorobots toward medical use. Ongoing optimization and safety evaluation are expected to move the technology closer to real-world therapeutic applications.

“This work offers a new strategy for the next-generation drug delivery, promising a paradigm shift for self-propelled nanorobots in precision medicine,” stated the authors.