For several years now, scientists have been exploring the use of patches of arrayed microneedles as a means of “injecting” medication through the skin. Researchers at North Carolina State University are now working on something similar, but at a much smaller scale – they're developing tiny needle-covered balloons, to deliver medication to individual cells.
The idea is that the needles on such a balloon could be coated with medication. The device would then be surgically inserted in the target area and inflated, causing the spikes on the expanding balloon to pierce the walls of adjacent cells, delivering the medication into them. Once that process was complete, the balloon could simply be deflated and withdrawn.
Before any of that can happen, however, the material which the spiky balloons will be made from needs to be created. That’s where the NC State team came in.
They started by growing carbon nanofibers on an aluminum substrate. Next, they added a drop of liquid silicone polymer. Then they spun the substrate, using centrifugal force to spread that polymer around between the fibers. This resulted in a thin layer of the polymer being evenly distributed across the aluminum, with the fibers poking up through it.
The next step was to cure the polymer, causing it to transform from a liquid into solid silicone. Finally, the aluminum substrate was dissolved, leaving nothing but a stretchy membrane studded with nanofibers. Those fibers are suitably perpendicular to the silicone surface, and are reportedly sturdy enough to impale cells.
“This technique is relatively easy and inexpensive, so we are hoping this development will facilitate new research on targeted drug-delivery methods,” said Dr. Anatoli Melechko, co-author of a paper on the research. That paper was recently published in the journal ACS Applied Materials & Interfaces.
Source: North Carolina State University