Achieving thermoresponsive behavior, electrical conductivity, printability, and biocompatibility within a single bioink formulation remains a significant challenge, yet this combination is essential for creating stable, electroactive 3D constructs that function under physiologically relevant conditions. To address this unmet need, this study aimed to develop a thermoresponsive and electrically conductive bioink through the systematic formulation and evaluation of 12 hydrogels composed of agarose, gelatin, HPC, and PEDOT:PSS. Among these, a formulation comprising 2% w/w agarose, 4% w/w gelatin, 2% w/w HPC, and 0.1% PEDOT:PSS exhibited the most balanced performance, demonstrating favorable shear-thinning rheology, high print fidelity, structural stability, and high electrical conductivity (0.5757 S/m). Comprehensive biological assays confirmed no significant changes in A549 cell viability across different embedding conditions, while SEM imaging of 3D-printed structures revealed micro- to mesoscale pores suitable for cell infiltration and small molecule transport. Critically, optimizing the PEDOT:PSS content enabled effective conductivity without compromising mechanical properties or biocompatibility. The systematic design approach demonstrated herein provides a reproducible framework for creating multifunctional conductive bioinks that successfully balance thermoresponsive behavior, printability, electrical conductivity, and biocompatibility in a single material. By integration of all essential functional properties into a single formulation, these findings advance the development of application-ready bioinks. The resulting printed structures can be used immediately, without any postprinting modification or functionalization, thereby supporting rapid translation into tissue engineering, biosensing, and bioelectronic applications.
Byrne et al. (Sun,) studied this question.