Drug releasing implants can be of great benefit for conditions requiring long term treatment in a targeted area of the body. There are existing devices on the market, but they tend to be bulky and involve electronics, mechanical valves, and other components that create their own drawbacks. Researchers at Purdue University have come up with a new way of releasing drugs into the body in a controlled manner using tiny injectable nanowire implants.
The devices are made of polypyrrole, an organic electrically conductive polylmer. A small carpet made of these wires was grown over a gold base and loaded with dexamethasone, a corticosteroid. Applying an electromagnetic field over the wires caused them to release the drug. Turning off the EM field immediately stopped the drug release process.
The team tested the technology on mice with compression injuries, demonstrating that the drug reduced inflammation in the areas where the EM field was applied. This worked over a period of weeks, pointing to this approach being applicable in long-term clinical applications.
From the study abstract in Journal of Controlled Release:
Approximately 1–2 mm2 dexamethasone (DEX) doped PpyNWs was lifted on a single drop of sterile water by surface tension, and deposited onto a spinal cord lesion in glial fibrillary acidic protein-luc transgenic mice (GFAP-luc mice). Overexpression of GFAP is an indicator of astrogliosis/neuroinflammation in CNS injury. The corticosteroid DEX, a powerful ameliorator of inflammation, was released from the polymer by external application of an electromagnetic field for 2 h/day for a week. The GFAP signal, revealed by bioluminescent imaging in the living animal, was significantly reduced in treated animals.
Study in Journal of Controlled Release: Remote-controlled eradication of astrogliosis in spinal cord injury via electromagnetically-induced dexamethasone release from “smart” nanowires…