Objective To synthesize bovine serum albumin(BSA)-loaded liraqlutide(Lir)-nanoparticles coated with platelet membrane fragments(PMF)using a"bottom-up"nano-engineering chemistry technique,and to evaluate their cyto-compatibility and potential function of anti-oxidative stress.Methods PMF was extracted as reported previously.Lir@BSA nanoparticles were prepared by self-assembly method.PMF was coated on the sur-face of Lir@BSA nanoparticles by co-extrusion to prepare Lir@BSA-PMF.The physical and chemical properties of Lir@BSA-PMF particles were characterized as particle size,Zeta potential,transmission electron microscopy and particle size stability.The encapsulation efficiency,loading efficiency and cumulative release efficiency of liraglu-tide were calculated by enzyme-linked immunosorbent assay.Further,SDS-PAGE was used to analyze whether there was a similar membrane protein distribution of platelet membrane on Lir@BSA-PMF bionicnanocarrier.CCK-8 assay was used to verify the biocompatibility of the materials.Reactive oxygen species(ROS)experi-ment was used to explore the effect of Lir@BSA-PMF on cell oxidative damage.The uptake of cells on Lir@BSA-PMF bionic nano capsules was verified by cell phagocytosis experiment.Results Lir@BSA-PMF nanop-articles had a stable particle size of 25 nm with a spherical morphology,and a Zeta potential value of-25.5 mV.The encapsulation efficiency,loading efficiency and cumulative release efficiency of liraglutide were 85.56％,7.96％and 77.06％,respectively.SDS-PAGE analysis showed that the Lir@BSA-PMF bio-mimetic nano capsules retained the similar membrane protein distribution as platelet membrane.CCK-8 assay verified that the nanomaterials were non-cytotoxic.ROS results showed that Lir@BSA-PMF nanomaterials had obvious antioxidant properties.The results of cell phagocytosis showed that the cells had a good phagocytosis effect on Lir@BSA-PMF nanoparticles.Conclusions The nanoparticles Lir@BSA-PMF are successfully syn-thesized and have no effects on cells viability in vitro.The particles are taken up by cells and show a significant function of antioxidant damage.