Dual-functional 3D-printed hydrogels for pH-responsive wound monitoring and on-demand therapy

The rapid and personalized management of wound infections remains a significant clinical challenge. This study addresses this need by developing a smart, dual-nozzle 3D-printed theranostic hydrogel pad for on-demand wound care. The platform is based on a tailor-made Pluronic F127-dimethacrylate (PF127-DMA) hydrogel, synthesized to provide optimal printability and dual-functionality. This enables the simultaneous extrusion of two distinct bioinks: a diagnostic ink containing bromocresol purple for pH sensing and a therapeutic ink loaded with graphene oxide (GO) and the antibiotic levofloxacin. The fabricated construct acts as an intelligent wound dressing, providing a distinct visual colorimetric response to differentiate healthy skin pH (4.0-6.0) from pathogenic, alkaline infection conditions (pH 7.4-8.0). Simultaneously, the system provides pH-responsive controlled drug release, with a significantly enhanced cumulative levofloxacin release of 171.68 ± 1.59 µg at pH 8.0 compared to 134.34 ± 1.46 µg at pH 7.4, demonstrating its ability for infection-triggered therapy. The incorporation of graphene oxide was found to critically improve drug release kinetics and promote intramatrix accumulation. Furthermore, <i>in vitro</i> MTT assays confirmed the high biocompatibility of the hydrogel platform. By integrating real-time visual monitoring with controlled antimicrobial release, this 3D-printed theranostic system presents a promising and scalable strategy for advanced wound management.