ESC Congress 2026 Abstract · Oct 26, 2026
Silicon carbide nanowires preserve human atrial microtissue function and show a preliminary reduction of AF duration in an aged-rat atrial tachypacing model
By Miragoli M, Berrettoni S, Statello R et al.
Background: Atrial fibrillation (AF) remains difficult to treat and current approaches (ablation/antiarrhythmic drugs) may be limited by durability and substrate-altering injury. Semiconductor nanomaterials such as silicon carbide nanowires (SiC-NWs) combine electrical properties with high biocompatibility and could enable non-destructive modulation of atrial electromechanical behavior. However, their interaction with human atrial cardiomyocytes and fibrillating atrial tissue is insufficiently characterized. Purpose: To assess the effects of SiC-NWs on human stem cell–derived atrial cardiomyocytes in 2D and 3D models, and to explore in vivo feasibility in an AF rat model. Methods: Human embryonic stem cell–derived atrial cardiomyocytes (hESC-aCMs) were cultured as 2D monolayers and 3D spheroids and exposed to SiC-NWs. Contractility parameters were quantified using the longitudinal optokinematic incubation platform (LOKI), including contraction time, relaxation time, and beat duration, with longitudinal follow-up up to 14 days in 3D spheroids. SiC-NWs localization was assessed by oblique plane microscopy (OPM). Cell membrane nanomechanics were measured by scanning ion-conductance microscopy (SICM). In parallel, inducibility of AF via rapid right-atrial tachypacing were evaluated in 24-month-old rats after left atria intramural injection of SiC-NWs, by means of epicardial grids positioned on atrium and ventricle. Results: In both 2D monolayers and 3D spheroids, LOKI showed preserved contractility parameters after exposure to SiC-NWs, with no detectable functional alteration during 14-day longitudinal screening in 3D. OPM fluorescence imaging demonstrated SiC-NWs interaction with the cell membrane and suggested intracellular localization. SICM revealed increased membrane stiffness (Young’s modulus ~1073 Pa to ~1292 Pa) after SiC-NWs exposure. In vivo, epicardial recordings showed a marked reduction in AF duration following atrial SiC-NWs administration compared to physiological solution injection (mean AF duration from 660±0 ms to 2201±693 ms, respectively) without evidence of acute electrical instability on ventricular recordings. Conclusion: SiC-NWs integrate with human atrial cardiomyocytes while preserving contractile function, alter membrane nanomechanics, and provide in vivo evidence of reduced AF burden in an aged-rat atrial tachypacing model. These data support further mechanistic and dose–response studies to define durability and translational potential of SiC-NWs–based atrial substrate modulation.