Purdue University researchers have created a new flexible, thin and translucent base for silicon nanoneedle patches. The base will help patches deliver exact doses of biomolecules directly into the cells.

Purdue University researchers have created a drug delivery method using silicon nanoneedles with diameters 100 times smaller than a mosquito's needle. These nanoneedles are embedded in a stretchable and translucent elastomer patch that can be worn on the skin to deliver exact doses directly into cells. Source: Purdue University

"This means that eight or nine silicon nanoneedles can be injected into a single cell without significantly damaging a cell. So 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's School of Mechanical Engineering as well as its Weldon School of Biomedical Engineering.

Current silicon nanoneedle patches have rigid bases, creating an uncomfortable patch that cannot be left in the body for long periods of time.

But the new flexible base may solve these issues.

"These qualities are exactly opposite to the flexible, curved and soft surfaces of biological cells or tissues," Lee said. "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. 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."

The team hopes to further develop the device so it can act as an external skin patch to lower the pain, invasiveness and toxicity associated with long-term drug delivery. Their next step is testing the patch’s ability to monitor electrical activity or treat cancer.

The paper on the new patch was published in Science Advances.