A hydrogel/P(VDF-TrFE) system for enhanced bone regeneration with controllable self-sustained electrical cues.

The limited self-healing capacity of critical-sized bone defects presents significant challenges in healing. An effective approach is to regulate the physicochemical properties of biomaterials to mimic the natural bone regenerative microenvironment. In this work, we have prepared Chitosan-Gelatin (CS-Gel) based hydrogel/ Poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) systems, which provide biomimetic and electric cues for bone regeneration. These hydrogel membranes are constructed on P(VDF-TrFE) layers, and the sustained electrical cues rely on the dipole orientation of P(VDF-TrFE). The bilayer structure decouples electrical stimulation and biocompatibility from chemical composition, allowing the generation of self-sustained electrical cues without altering the functional groups on the hydrogel surface. The results show that these hydrogel/P(VDF-TrFE) systems are more effective in polarizing macrophages toward the alternatively activated (M2) phenotype and promoting stem cell differentiation in vitro. Furthermore, the hydrogel/P(VDF-TrFE) system enhances the expression of anti-inflammatory cytokines and encourages new bone formation in vivo. This work presents a promising strategy to accelerate bone regeneration by combining electrical cues and biomimetic environments, offering a new preparation method for hydrogel/P(VDF-TrFE) systems with self-sustained electrical cues.