This painless nanoneedle patch might one day replace certain biopsies

A patch containing tens of millions of nanoneedles can read what’s happening in our cells on the fly, potentially eliminating the need for time-consuming biopsies. The patch might also facilitate disease diagnosis and monitoring.

The 8-by-8-millimeter patch collects molecular information painlessly and without damaging tissue, providing results in a matter of minutes, researchers report June 16 in Nature Nanotechnology. Traditionally, diseases like cancer and autoimmune conditions require biopsies. Extracting these tissue samples can be painful and invasive, and results can take days.

The patch consists of tiny needles made of porous silicone. The tip of each needle is just 50 nanometers wide, or roughly the width of about 60 atoms. These needles can access cell interiors with minimal membrane damage and extract components such as proteins, messenger RNA and lipids without harming the cells.

In this study, the researchers focused on lipids, fatty compounds essential for the functioning of living beings. The team applied the patch to brain cancer tissue from both human biopsies and mice bred for the experiment. Mass spectrometry provided information about lipid composition at every point on the patch.

Using various AI models, the team compared the resulting 2-D maps of lipid compositions with those from biopsy samples with known results. In 25 out of 27 sample comparisons, the results from the two methods were similar. That suggests that the tissue samples collected by the patch contained sufficient information to detect a tumor, monitor disease progression or assess treatment response.

“It’s not an invasive method, because the tip size is very small, and it doesn’t disrupt the cell membrane in a way that cannot be repaired,” says Ciro Chiappini, a nanotechnology and bioengineering researcher at King’s College London.

Although this study was limited to lipids and a type of tumor called glioma, the team is working to expand the patch’s capabilities. “We have data that shows that we can do the same type of analysis with the mRNA and proteins,” Chiappini says.

Thanh Nho Do, a biomedical engineer not involved with the study, calls this technology promising and especially useful for repeated, nondestructive sampling and high-resolution molecular mapping of live tissues. “It is particularly valuable for tracking disease progression and therapeutic response in metabolically active tumors like gliomas,” says Do, of the University of New South Wales in Sydney. However, he adds, the patch’s inability to sample tissues deeper in the body is a limitation.

Chiappini concurs. “It’s very much a surface technology, which is potentially [both] a limitation and a feature,” he says. He envisions applications during surgeries, allowing doctors to get quick results about tissue they need to operate on. The patch could also replace biopsies in screening settings, such as for oral cancer, eye conditions and atherosclerosis, and assist in wound monitoring.