UCLA

Stable bioelectronic interfaces require coupling materials that conform to irregular tissue surfaces and accommodate deformation while maintaining cohesion, wet-tissue adhesion, and electrical continuity. Here, we introduce GelMA-BioIL nanoparticle-TA (GBT), a tissue-adhesive ionic paste formed through tannic acid (TA)-mediated supramolecular assembly of gelatin methacryloyl (GelMA) nanoparticles conjugated with the polymerizable quaternary-ammonium monomer [2-(methacryloyloxy)ethyl]trimethylammonium chloride (BioIL). This particulate architecture separates ion-conductive nanoparticle formation from macroscopic network assembly, enabling structural rearrangement during injection and deformation, while multivalent TA interactions maintain cohesion and adhesion. The optimized water-rich, shear-thinning paste established conformal adhesion across diverse wet tissues without post-application curing. GBT maintained conduction during elongation, exhibited strain- and compression-dependent electrical responses, and restored electrical continuity upon recontact of cut surfaces. The paste also supported in vitro fibroblast viability and reduced macrophage CD80 expression under pro-inflammatory stimulation. In single-animal feasibility studies, GBT enabled electrocardiogram (ECG) recording in a mouse model and restored interrupted ECG signals in a porcine model. Together, these findings establish supramolecular nanoparticle assembly as a strategy for integrating wet-tissue adhesion, mechanical adaptability, and deformation-tolerant ionic conduction within a conformal bioelectronic interface.