Researchers Develop Comfortable, Transparent Nanoneedle Patch

Posted November 26, 2018

Researchers from Indiana’s Purdue University and South Korea’s Hanyang University have developed a patch with flexible needles so small that as many as nine can be injected into a cell without damaging it. The patch is intended to help reduce the discomfort associated with previous, more rigid nanoneedle patch designs.

“We can use these nanoneedles to deliver biomolecules into cells or even tissues with minimal invasiveness,” said Chi Hwan Lee, an assistant professor at Purdue University’s Weldon School of Biomedical Engineering and School of Mechanical Engineering and an author of the study, in a statement. “This nanoneedle patch is not only flexible but also transparent, and therefore can also allow simultaneous real-time observation of the interaction between cells and nanoneedles.”

Although most nanoneedles patches are currently placed between skin, muscles, or tissues, Lee said the researchers hope to develop the new design as an external skin patch so they can help reduce the pain, invasiveness, and toxicity associated with long-term drug delivery.

The new nanoneedle patch design is particularly exciting for the study and treatment of skin cancers, according to the researchers. Because it is 90% transparent, it won’t get in the way of observing how well treatment is progressing. The improved flexibility and biocompatibility of the nanoneedle patch also holds promise beneath the skin, where it could be implanted to directly treat or observe muscle cells.

Previous nanoneedle designs built the needles onto a silicon wafer, which is rigid and opaque. To help solve that problem, the researchers at Purdue and Hanyang University, developed a method of “controlled cracking” to separate the nanoneedles from their silicon wafer. The nanoneedles are then transferred onto a flexible bio-patch.

“Although production of these silicon nanoneedles on a bulk silicon wafer has been achieved through standard nanofabrication technology, there exists a large mismatch at the interface between the rigid, flat, and opaque silicon wafer and soft, curvilinear, and optically transparent biological systems,” the researchers wrote in study published in the November issue of the journal Science Advances.