Flexible biopatch uses nanoneedles for precision drug delivery

According to the researchers, skin cancer is a prime candidate for treatment with the patch. The silicon needles have a diameter 100 times smaller than that of a mosquito, allowing for ultra-precise penetration that leaves individual cells intact.

"This means that eight or nine silicon nanoneedles can be injected into a single cell without significantly damaging a cell,” said Chi Hwan Lee, an assistant professor in Purdue University's Weldon School of Biomedical Engineering and School of Mechanical Engineering. “So we can use these nanoneedles to deliver biomolecules into cells or even tissues with minimal invasiveness."

Commercially available nanoneedle patches are usually constructed on a rigid and opaque silicon wafer. However, this rigidity can cause discomfort, preventing extended use. What’s more, observation of the skin beneath is obscured, making it difficult to track the efficacy of the treatment.

"To tackle this problem, we developed a method that enables physical transfer of vertically ordered silicon nanoneedles from their original silicon wafer to a bio-patch," said Lee. "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.”