3D stretchable and conductive scaffold for the in situ cell culture and real time profiling of extracellular H2S

Hydrogen sulfide (H 2 S) serves as the third gaseous signaling molecule in biological systems and is crucial for the regulation of biological cells. However, due to the lack of real time analysis techniques, studies on cellular release of H 2 S may yield inaccurate information and differ significantly from the three-dimensional (3D) cellular in vivo conditions. In this paper, a stretchable conductive 3D scaffold integrated with 3D cell culture, strain loading as well as electrochemical detection was proposed for real time profiling of H 2 S secreted from cells. In our design, single-walled carbon nanotube (CNTs)-impregnated 3D PDMS was used as the conductive substrate scaffold, which was subsequently functionalized with ZIF-8 and gold nanostars (AuNSt). The obtained stretchable AuNSt/ZIF-8/CNTs/PDMS scaffold achieved sensitive electrocatalytic performance toward H 2 S while maintaining excellent mechanical stability. The favorable biocompatibility of the 3D scaffold facilitated the attachment and growth of endothelial cells in culture, enabling in situ inducing and real time tracking of H 2 S secretion during mechanotransduction and pharmacological interventions. This study provided a multifunctional platform for 3D cell culture and to investigate the molecular mechanism related to endothelial dysfunction and vascular disorder.