Check out some brand new biomedical tech – crazy cool, in my own, humble but admittedly biased opinion – introduced in our paper (link below), published today in @Nature, titled “Millimetre-scale, bioresorbable optoelectronic systems for electrotherapy,” where we describe the world’s smallest cardiac pacemaker – fully integrated, self-powered, light-controlled and completely bioresorbable, with an overall size that is somewhere between that of a grain of rice and a sesame seed! The clinical use case is for patients – particularly pediatric patients – who require temporary pacing during the recovery period following a cardiac surgery. Our tiny technology can be delivered through a syringe, with minimal burden and without the need for a secondary extraction surgery. A small, soft skin-interfaced electronic patch on the chest monitors the cardiac rhythm and activates switching elements in these pacemakers when necessary, in an autonomous, closed-loop manner, using LEDs that operate at tissue-penetrating wavelengths in the infrared region. Single or multisite pacing is possible, the latter controlled using multiple LEDs with different wavelengths. More generally, these miniature pacemakers are electrical stimulators that can be sprinkled around for operation at nearly any body location – spinal cord, brain, peripheral nerves and others. They can also be mounted on conventional, non-electronic implants, as we demonstrate with frameworks used in transcatheter aortic valve replacement (TAVR) procedures, again in the context of postsurgical recovery. The work – from materials and device development, to comprehensive electrical and optical modeling, to animal model testing, to TAVR deployments, to evaluations with human hearts from organ donors -- involved broad-ranging collaborations at the interface between engineering science and medical practice. Big congratulations to @Yamin__Zhang (former postdoc, now a Presidential Young Professor at the National University of Singapore), Eric Rytkin (MD, PhD cardiac surgeon in the Efimov group), @LiangsongZeng (PhD student), Jong Uk Kim (postdoc), @Ja_T_23 (joint PhD student with the Efimov group), @healsea1994 (postdoc in the Huang group) on their leadership across the entire multidisciplinary scope of this difficult project. We’re also grateful to an elite collection of senior collaborators -- @IEfimov (@NorthwesternU), Yonggang Huang (@NorthwesternU), Wei Ouyang (former postdoc, now on the faculty at @dartmouth ) and Rishi Arora (@NorthwesternU, now at @UChicago ). We acknowledge the @FondationLeducq, the @NU_QSIB and @NIH for providing financial support for this work. Thanks to @amanda_mo and @schamisso for the release materials. Link below. nature.com/articles/s41586-0… news.northwestern.edu/storie…

Beyond being magnetically susceptible, contrast agents for MRI can be designed to bind to specific disease biomarkers, or to alter their magnetic properties in response to environmental changes. nature.com/articles/s41551-0…