BS41 Rational design of robust mesh biolectronics for stable physiological interrogation of cardiomyocytes

Cardiovascular diseases remain a leading cause of morbidity and mortality worldwide. Despite significant advancements in treatment, there is an urgent need for novel therapeutic solutions. In vitro engineering of cardiac tissue offers promising avenues for regenerative medicine and drug therapy. However, conventional in vitro methods for culturing cardiomyocytes (CMs) often fail to recapitulate the complex phenotype of native cardiac tissue as well as the complex three-dimensional microenvironment of the native myocardium, limiting their translational potential. To address this challenge, we propose a multidisciplinary approach to enhance the phenotype of CMs cultured in vitro by introducing a mesh bioelectronic scaffold capable of electrically interrogating CMs in both a 2D and 3D culture settings. Initially inspired by neural interface technologies, we developed our own bioelectronic device utilizing photolithography techniques that features a flexible mesh made of gold electrode ribbons coated with a biocompatible polymer (SU-8). Using this device, we established a means of directly interfacing with CMs. CMs readily attach to the device after coating with fibronectin and can be electrically stimulated via internal stimulating electrodes. Culturing CMs on the device increased cell alignment (nuclear aspect ratio of 1.4 for CMs on the device versus 1 for CMs in 2D control cultures; p<0.01, n=3). Delivery of electrical stimulation further improved alignment and contractility (nuclear aspect ratio 1.77 vs. 1.4, p<0.01, n=40 cells; contraction amplitude: 900 a.u. with electrical stimulation versus 400 a.u. without electrical stimulation, p<0.001, n=3). Although the application of a neural bioelectronic device design to CMs acts as a proof of concept, it has become apparent that further optimization would be necessary for cardiac models and revisions of the bioelectronic mesh design would need to be carried out for the specific physiological characteristics of CMs. To enhance the robustness of the mesh bioelectronic device and optimize the mesh scaffold design specifically for CMs, we refined the selected ribbon widths (30–60µm), reducing the spacing between ribbons for better cell proximity, and increasing device thickness for enhanced stiffness (5pPa vs. 0.5pPa) and handling. These modifications have significantly improved cell-to-device interaction, promoting cell elongation and attachment. Future work will evaluate the effect of the new device geometry and stiffness on CMs calcium handling. These preliminary results indicate that our bioelectronic platform shows promise in creating cardiac tissue models for regenerative medicine, potentially offering a new avenue for cardiovascular disease therapy. Conflict of Interest N/A