Phosphorus magnesium fiber regulates macrophage polarization through TRPM7 to accelerate wound healing

Wound healing is a complex process that can be delayed by persistent inflammatory responses after trauma. Many studies have found that in situ application of biomaterials releases metal ions into wounds to promote wound healing, but the underlying mechanism has not been elucidated. Therefore, we developed a novel nanoscale functional material, phosphorus magnesium fiber (PMF), as a wound dressing to explore its association with wound healing. In this study, in vivo wound healing results showed that PMF accelerated wound closure in full-thickness wound animal models, accompanied by collagen deposition and granulation formation. Moreover, PMF accelerated macrophage polarization by regulating TRPM7-ERK1/2 signaling through the long-term release of magnesium ions into the wound, which contributes to enhancing cell proliferation, growth factor production, and synthesis of ECM in the wound bed, ultimately facilitating wound healing. In vitro studies revealed that PMF promoted the polarization of macrophages to the anti-inflammatory M2 phenotype. Meanwhile, PMF up-regulated TRPM7-ERK1/2 expression. In conclusion, our study confirmed the relationship between PMF and macrophage behavior mediated by the TRPM7 channel protein and subsequently investigated the function of PMF in wound healing. This magnesium-based nanofiber material offers an innovative method for treating open wounds and is anticipated to be used as a wound dressing in the field of tissue regeneration.