NIR‐Inducible Pyroelectric Nanocomposite Membrane Promotes Macrophage Reprogramming for Superior Bone Regeneration

Abstract Electroactive materials have demonstrated positive efficacy in facilitating bone repair, but often fail to dynamically adapt to complex and variable immune responses within the bone defect microenvironment, leading to unsatisfactory repair outcomes. Here, a dynamic and non‐invasive osteo‐immunomodulatory strategy based on electrothermal synergistic effects is developed. By utilizing the photothermal absorption property of polydopamine, PDA@BTO/P(VDF‐TrFE) nanocomposite membranes can be heated by near‐infrared (NIR) irradiation and maintained at 41 °C. Simultaneously, the temperature increase also releases polarized charges due to pyroelectric effects on the nanocomposite membrane. These induce stage‐specific M1 or M2 polarization during the early phases of bone regeneration on days 2 and 7, respectively, thereby enhancing new bone formation in a rat calvarial defect model via the HSP70/AKT‐NF‐κB signaling pathway. Hence, the effective synergy of the photothermal and pyroelectric effects through NIR irradiation of PDA@BTO/P(VDF‐TrFE) nanocomposite membranes is able to exert a positive immunomodulatory effect on macrophages for superior bone repair. This remote, non‐invasive, long‐acting, and controllable strategy represents a novel clinical approach for bone immunomodulation and regeneration.