Smart stent: It’s fully loaded but not yet ready to roll

Call it the smart stent. An international group of researchers has designed a multifunctional, bioresorbable, drug-toting stent fitted with sensors and memory storage devices to provide diagnostic feedback and localized therapy.

Donghee Son, PhD, of the Center for Nanoparticle Research at the Institute for Basic Science in Seoul, South Korea, and colleagues from the U.S. and China, are collaborating on what they termed a bioresorbable electronic stent for treating coronary and endovascular stenosis. Unlike inert stents, the device incudes nanomembrane blood flow and temperatures sensors, inorganic anti-inflammatory nanoparticles and nanospheres loaded with drugs that can be optically activated.

“This suite of sensors and actuators provides mechanical, photothermal, diagnostic, and therapeutic functionality on bioresorbable stent substrates,” they wrote in a paper published online April 23 in ACS Nano.

The design starts with a magnesium alloy stent incorporating layers of ceria nanoparticles and the drug rapamycin for treating restenosis plus sensors and a memory array made of bioresorbable and bioinert materials. The stent itself acts an antenna for the wireless electronics.

They conducted in vivo pharmacokinetic studies in mice and histological analyses to assess biodistribution and biocompatibility as well as in vitro studies on the therapeutics. They also analyzed the stent’s mechanical strength and integrity and tested its wireless data transmission in ex vivo and in vivo studies. In a final step using near infrared lasers, they showed that they could thermally control the dosage of drugs released.

“This system with onboard resorbable sensors and memory modules resolves the limitations of existing stents by enabling the acquisition of physiological signals, data storage, anti-inflammation, localized drug delivery, and photothermal therapies through minimally invasive and/or noninvasive optical control,” they wrote.

Their next step is to integrate wireless power and data communication functions into the system.