'Balloon' technique could lead to new drug-delivery systems

Researchers at North Carolina (NC) State University have developed a technique to embed needle-like carbon nanofibres in an elastic membrane — an advance that could lead to new drug-delivery systems.

Finding new ways to deliver precise doses of drugs to specific targets is of interest to the research community and one way to do this is to create balloons embedded with nanoscale spikes that are coated with the relevant drug.

In theory, the deflated balloon could be inserted into the target area and then inflated, allowing the spikes on the balloon’s surface to pierce the surrounding cell walls and deliver the drug. The balloon could then be deflated and withdrawn.

To test this concept, researchers first needed to develop an elastic material embedded with these aligned, nanoscale needles.

‘We have now developed a way of embedding carbon nanofibres in an elastic silicone membrane and ensuring that the nanofibres are both perpendicular to the membrane’s surface and sturdy enough to impale cells,’ said Dr Anatoli Melechko, an associate professor of materials science and engineering at NC State and co-author of a paper on the work.

The researchers first grew the nanofibres on an aluminium substrate, then added a drop of liquid silicone polymer. The polymer, nanofibres and substrate were then spun so that centrifugal force spread the liquid polymer in a thin layer between the nanofibres, allowing the nanofibres to stick out above the surface.

The polymer was then cured, turning the liquid polymer into a solid, elastic membrane. Researchers then dissolved the aluminium substrate, leaving the membrane embedded with the carbon nanofibre needles.

‘This technique is relatively easy and inexpensive, so we are hoping this development will facilitate new research on targeted drug-delivery methods,’ said Melechko in a statement.’

The paper, Transfer of Vertically Aligned Carbon Nanofibers to Polydimethylsiloxane (PDMS) while Maintaining their Alignment and Impalefection Functionality, is published online in the journal ACS Applied Materials & Interfaces.