Advances in conductive polymer-based composites: Structural design, fabrication strategies, and biomedical applications

Conductive polymer (CP)-based composites have attracted increasing attention as electroactive biomaterials due to their electrical conductivity, structural tunability, mechanical flexibility, and versatile biointerfaces. By incorporating representative CPs, including polypyrrole, polyaniline, polythiophene, and poly(3,4-ethylenedioxythiophene), with carbon nanomaterials, inorganic nanophases, hydrogels, and biomacromolecules, these composites can overcome the intrinsic limitations of single-component CP, such as insufficient conductivity, suboptimal processability, mechanical brittleness, restricted physiological stability, and inadequate biofunctionality. This review summarizes recent advances in CP-based composites from the perspectives of conductive mechanisms, structural design, fabrication strategies, and biomedical applications. Particular emphasis is placed on how doping engineering, molecular ordering, nanoscale morphology, interfacial engineering, and multicomponent integration regulate charge transport, ionic–electronic coupling, mechanical behavior, and biological performance. Representative fabrication approaches, including chemical polymerization, in situ polymerization, electrospinning, hydrogel construction, nanostructural control, and hybrid-system assembly, are discussed. We further highlight applications in tissue engineering, biosensing, wound healing, and cancer theranostics, where CP-based composites function as electroconductive scaffolds, electroactive sensing interfaces, responsive therapeutic platforms, and bioelectronic interfaces. Finally, we discuss structure–property–function relationships and key challenges related to long-term physiological stability, biosafety, biodegradation, scalable manufacturing, and clinical translation are discussed, thereby providing a framework for the rational design of next-generation CP-based biomedical composites.