Study On Preparation Of The Macrophage Vesicle Membrane-coated Nano-prodrugs And Their Applications In Anti-atherosclerosis

Atherosclerosis（AS）is the main pathological basis of ischemic cardiovascular disease,with high morbidity and mortality.In recent years,the targeted therapy of AS has become a research hotspot.However,the current nano-drug delivery system used for AS targeted therapy still has problems such as short circulation time in the body of nanoparticles,lack of targeting,and poor controllability of drug release.Based on the inherent AS-targeting biological function of macrophages and the slightly acidic environment of AS lesions,this thesis constructed a biomimetic nanoprodrug delivery system coated with macrophage vesicle membrane for the treatment of AS.The system can play the function of long-term circulation in the body and specifically identify AS lesions through the"camouflage"of the macrophage vesicle membrane,so as to achieve efficient targeted drug delivery to AS.In addition,the targeted aggregation of biomimetic nanoprodrugs can further respond to pathological acid stimulation and achieve the function of local drug controlled release,thereby improving the bioavailability and therapeutic efficacy of the drug,and achieving efficient and safe treatment of AS.The main research contents and conclusions of this paper are as follows:（1）Preparation and characterization of biomimetic nano-prodrugsIn order to prepare prodrug nanoparticles with negative charges on the surface,the hydrophilic polymer polyacrylic acid（PAA）containing carboxyl groups and the hydrophobic drug Docetaxel（DTX）were synthesized through active ester bonds to synthesize acid-sensitive drugs.Prodrug polymer with controlled release capability（PAA-DTX）.Prodrug nanoparticles（PDNPs）were prepared by nanoprecipitation method.DLS and Zeta potential characterization results showed that the average particle size of PDNPs was 201.6 nm and the surface potential was-29.1 m V.In addition,cytochalasin B（Cytorelaxin B,CB）is used to stimulate macrophages to produce a large number of vesicles,and a centrifugal-hypotonic method is used to obtain Macrophage vesicle membrane（MVM）.Subsequently,biomimetic nanoprodrugs（MVM/PDNPs）were prepared by coating MVM on PDNPs by coextrusion technology.The characterization results of DLS and Zeta potential showed that the average particle size of the synthesized MVM/PDNPs was 238 nm and the surface potential was-22 m V.Western blot results showed that MVM/PDNPs retained the characteristic and functional proteins of the macrophage vesicle membrane.（2）In vitro biocompatibility and functional evaluation of biomimetic nanoprodrugsIn order to further verify the biocompatibility and functional properties of MVM/PDNPs,the biocompatibility and targeting functions of MVM/PDNPs were tested through hemolysis test,macrophage phagocytosis test,endothelial uptake test,anti-macrophage and smooth muscle cell proliferation in vitro test Researched.The results show that MVM/PDNPs have good biocompatibility.Thanks to the functional membrane coating of MVM,MVM/PDNPs can effectively inhibit the phagocytosis of macrophages and efficiently target inflammatory endothelial cells.In addition,MVM/PDNPs can effectively inhibit the proliferation of macrophages and smooth muscle cells.（3）Anti-AS and safety evaluation of macrophage membrane-coated nanoprodrugs in vivo.Apo E^-/-mice were used to construct an AS model,and the ability of MVM/PDNPs to target AS to lesions was evaluated;as well as the efficacy and safety of AS in vivo treatment.During the one-month treatment,MVM/PDNPs can significantly inhibit the development of AS and exhibit good in vivo treatment safety.All in all,we have successfully prepared macrophage vesicle membrane-coated nanoprodrugs MVM/PDNPs.In vivo and in vitro experiments have shown that MVM/PDNPs can effectively and safely inhibit the development of AS,providing useful ideas for the therapeutic application of AS.