Magnetically-powered nanorobots enhance drug uptake in tumors

Spiky nanorobots powered by magnets have been developed to carry drugs and pierce tumor cell membranes, a key barrier to effective cancer treatment. By boosting drug entry, these "microscopic scalpels" improved chemotherapy results in laboratory and animal studies, suppressing tumor growth and extending survival. The approach tackles drug resistance and could open new possibilities for safer, more precise therapies, marking a step forward in overcoming one of cancer's toughest defenses.

Getting drugs past a cancer cell's protective shield is one of the toughest challenges in oncology. Tumor cells defend themselves by forming rigid membranes that block medicine from entering. Even when drugs do get inside, many cancer cells use "efflux pumps" to push them back out, leading to drug resistance. These defenses often make chemotherapy less effective, especially in aggressive or late-stage cancers.

To address this problem, a team of experts has introduced a new strategy involving spiky nanorobots powered by magnets. These tiny machines function like "microscopic scalpels," enabling them to penetrate tumor defenses and enhance the effectiveness of chemotherapy drugs. The study, published online on August 13, 2025, in volume 8, issue 0768 of the journal Research, was co-led by Dr. Zhilu Yang from The Tenth Affiliated Hospital, Southern Medical University, Dr. Xing Ma from Harbin Institute of Technology (Shenzhen), and Dr. Ning Liu from Tongji University, China. The findings demonstrate how these nanorobots improve drug delivery and treatment outcomes. In laboratory and animal experiments, the nanorobots increased drug penetration into tumor cells, suppressed tumor growth, and even extended survival rates.

These nanorobots essentially act as mechanical agitators. By rotating under a magnetic field, their sharp spikes disrupt the cell membrane, creating tiny openings that allow drugs to slip inside more efficiently."

Dr. Ning Liu, Tongji University

Drug delivery encounters two main challenges: the cell membrane and drug-resistant tumor cells that expel medication. While nanocarriers like liposomes have made progress, they still have limitations regarding stability, targeting, and drug release. A new approach using nanorobots overcomes these issues by physically opening the cell's barrier.

The researchers designed the robots using gold nanospikes about 500 nanometers wide—roughly 200 times thinner than a human hair. A nickel coating made them responsive to magnets, while titanium improved safety inside the body. Under an external magnetic field, the nanorobots could be guided to tumors and spun in place. Their jagged spikes then pierced cell membranes, generating localized pressure strong enough to create "pores" for drugs to pass through.

In experiments with human liver cancer cells, robots significantly increased the uptake of doxorubicin, a standard chemotherapy drug. Longer application of the magnetic field led to greater drug entry, with fluorescence imaging showing much higher concentrations inside the cells. These results were consistent across different tumor types, including cervical and colon cancer models.

"Think of it as giving the drug a shortcut," says Dr. Ma, "Instead of relying on slow diffusion or being blocked by resistance mechanisms, the nanorobots create a mechanical pathway that drugs can use to reach the inside of the cell directly."

Computer simulations confirmed these findings, demonstrating that as the spikes rotated, they created pores in the membrane, which increased its permeability. Over time, the robots not only increased drug uptake but also directly damaged cancer cells through a process that the researchers refer to as "mechano-killing."

Encouraged by these results, the team decided to test their approach on mice with liver tumors. The group treated with both nanorobots and chemotherapy showed a 61% reduction in tumor growth and a 100% survival rate, with improved overall health compared to those given only chemotherapy or magnetic stimulation. Tissue analysis confirmed higher cancer cell death and minimal side effects, indicating strong safety potential.

"This dual approach—combining chemotherapy with mechanical disruption—represents a powerful new direction for cancer treatment," says Dr. Yang. "It shows that physical forces, when applied at the nanoscale, can work hand-in-hand with drugs to overcome cancer's defenses."

Researchers note that, while the results are promising, the technology is still in its early stages. More work is required before testing spiky nanorobots on humans, including design refinement, long-term safety, and improved delivery methods.

Overall, the results represent a promising advancement. By transforming nanorobots into microscopic scalpels, scientists have shown that it may be possible to physically cut through cancer's shield—making treatments more effective, less toxic, and better suited to the fight against drug-resistant disease.