Implants could provide data, then dissolve
Dissolvable electronic implants could be used to transmit vital data for short durations with lower infection risks than those associated with conventional implants.
A scientific article, “Bioresorbable silicon electronic sensors for the brain,” published earlier this year, indicates tests on rats showed such implanted silicon-based sensors could provide several days of temperature and pressure information useful in treating traumatic brain injury before the sensor encapsulation layers are permeated by liquids. The sensors had accuracy similar to that of available commercial sensors, the article states.
“In vivo and in vitro experiments demonstrate precision measurements of pressure, temperature, motion, flow, thermal properties and pH, with possible extensions to biomolecular binding events,” the article states. “These features will be useful in diagnosing and treating a diverse range of medical conditions, from acute traumatic injuries such as extremity compartment syndrome, to chronic medical diseases such as diabetes.”
The study results indicated that a pressure sensor in a rat provided intracranial pressure data for three days without notable degradation in accuracy or sensitivity in comparison with a standard wired sensor. A temperature sensor provided accurate measurements for six days.
The article also describes conventional implants as nidi for infection, and implant removal surgeries as sources of stress and complications.
The dissolvable sensors contain a combination of silicon membranes and wafers, silicon oxide coating, magnesium foil, molybdenum wires, and poly(lactic-co-glycolic acid). Components dissolve within days or weeks through hydrolysis and metabolic action. The article cites other studies indicating the PLGA used, for example, dissolves in bodily fluids within five weeks.
The authors are affiliated with the University of Illinois, Washington University, Korea University in Seoul, Pennsylvania State University, the Institute of High Performance Computing in Singapore, Purdue University, and Northwestern University.