摘要Objective:To construct a spatiotemporal controlled-release system of a biomimetic membrane-fused folate nanoparticles and investigate its synergistic restorative effect on the SIRT1/FOXO1 signaling pathway in aging placenta and the regulatory mechanism of placental function.Methods:Poly(lactic-co-glycolic acid)(PLGA)nanoparticle cores were synthesized using the emulsion-solvent evaporation method.Folate targeting modification was achieved via EDC/NHS-mediated carboxyl-amino coupling.Syncytiotrophoblast membranes were isolated from placental tissue through hypotonic lysis,differential centrifugation,and ultrasonication to prepare membrane fragments.The biomimetic membrane-coated folate nanoparticle system was constructed using liposome membrane fusion technology and the time-drug release curve(281 nm)was plotted using a dialysis method.An aging placenta rat model was established and divided into a control group and an experimental group.The control group was intervened with folic acid,while the experimental group received the developed system.Western blotting and qPCR were used to detect and compare the expression levels of key molecules in the SIRT1/FOXO1 pathway.Results:In the experimental group,drug molecules exhibited absorption at 281 nm,and with the prolongation of drug release time,the absorption peak of the dialysate gradually increased and stabilized after 10 h.The number and body weight of fetal rats in the experimental group were similar to those in the control group,and both were higher than those in the model group(P<0.05).There was no statistically significant difference in the placental malformation rate between the experimental group and the blank group,but it was lower than that in the model group and the control group(P<0.05).The levels of SIRT1/GAPDB,FOXO1/GAPDB,SIRT1 mRNA,and FOXO1 mRNA in the placental tissues of the experimental group were close to those in the blank group,and significantly higher than those in the model group and the control group(P<0.05).Conclusion:The biomimetic membrane-fused folate nanoparticle system exhibits controlled-release properties and synergistically activates the SIRT1/FOXO1 signaling pathway,improving placental developmental function in rats and reducing offspring malformation risk.This system provides a novel targeted therapeutic strategy for placental aging-related pregnancy complications.