Some cancer research starts with a new molecule. This project starts with a device so small that an external magnetic field can activate it inside tissue.
MIT researchers have developed glioblastoma nanoantennas designed to generate local electric fields around brain-cancer cells. The work, published on 9 September in Science Advances, tests an approach called HITMAN against glioblastoma, including chemotherapy-resistant cells obtained from patients. MIT’s research announcement
The evidence is preclinical. The patients supplied tumour material; they were not treated with the experimental devices.
A cancer that spreads through the tissue around it
Glioblastoma is an aggressive brain cancer that grows into nearby healthy tissue. That makes it difficult to remove completely. Mayo Clinic describes it as a grade 4 glioma, a classification reflecting its aggressive behaviour. Mayo Clinic’s disease overview
The scientific challenge is therefore broader than shrinking a clearly separated lump. Researchers need ways to affect tumour cells while preserving the surrounding brain.
That is the appeal of a treatment effect generated close to its target. Whether it can be delivered widely enough throughout a human tumour, with acceptable safety, remains a separate question.
How the glioblastoma nanoantennas work
The nanoantennas are approximately 150 nanometres across. Their materials respond to a magnetic field by deforming; that deformation produces local electric fields through a piezoelectric component. Piezoelectric materials convert mechanical stress into electricity.
The MIT team reports that the resulting fields disrupt processes inside the cancer cells, including the handling of proteins and the integrity of cell membranes. The devices are activated wirelessly, but “wireless” describes the activation step. It does not eliminate the need to deliver the material to the tumour. How the nanoantennas work
What the results actually mean
In the reported laboratory comparison, the approach reduced viability in drug-resistant, patient-derived glioblastoma cells by 52.2%, compared with 10% for temozolomide under the experimental conditions. Neurons and astrocytes, important healthy brain cells, were spared in those tests.
The team also implanted patient-derived tumour cells into mouse brains. Treatment inhibited tumour growth and extended median survival by more than 50%. The study abstract reports no systemic toxicity in those experiments. Study abstract and publication record
These percentages measure different outcomes. The laboratory figure concerns cell viability. The mouse figure concerns survival time. Neither is a human response rate, and neither means the cancer was cured.
The questions a human study would have to answer
The next evidence needs to address delivery, dose, distribution and durability. Researchers would need to determine where the particles travel, how long they remain active and what repeated treatment does to healthy tissue. Human tumours and mouse models also differ in scale and complexity.
Those are questions for further development, not findings already established by this study. Absence of detected toxicity in an experiment cannot establish the long-term safety of a new device in people.
The work belongs alongside other early efforts to use engineered materials against difficult cancers, including the targeted MRI research we recently covered. One aims to reveal tumours more clearly; the other seeks to damage them locally.
The compelling idea is that an externally controlled device might eventually reach resistant cancer through a different mechanism. The important milestone now is a promising experimental result that can be tested further.
Original paper: Monochura Saha and colleagues, “Magnetically actuated nanoantennas for wireless glioblastoma therapy,” Science Advances. Publisher DOI.
Featured image: Digital brain illustration; not a patient scan or an image from the nanoantenna experiments. Image: Shawn Day / Unsplash.
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