Preparation Of Biomimetic Nanomaterials And Their Anti-atherosclerosis Research

Atherosclerosis（AS）,as a disease that mainly affects human blood vessels,is the result of multi-faceted joint influence.It can induce various cerebral ischemic diseases such as coronary heart disease and peripheral arterial disease.The current clinical treatment of AS mainly adopts drug therapy and surgery,but traditional oral anti-inflammatory drugs have low bioavailability,poor target specificity and high toxicity,and surgical intervention（such as stent placement）is often accompanied by restenosis,advanced stent thrombosis and other side effects,hinder the long-term success of surgical intervention.Nano-drug delivery systems have been widely used because of their outstanding properties such as improving drug distribution,increasing drug absorption rate,prolonging drug half-life,and reducing drug toxicity and side effects.However,traditional nanotechnologies delivery systems are difficult to be recognized by normal biological systems,so they are easy to be removed as foreign bodies,resulting in the difficulty of targeting drugs to get to the diseased region.So as to enable AS to obtain safe and efficient curative effect,this study used the cell membrane protein and cytoplasmic protein extraction kit to extract the cell membrane,and coated the surface of synthetic carbon nanoparticles to prepare a targeted and safe biomimetic nano-drug delivery system MMCNPs.Studies have shown that MMCNPs have typical nano-properties,such as long-term blood circulation and efficient targeting of AS lesions.The research work of this paper is mainly carried out from the following three aspects:（1）Carbon nanoparticles（CNPs）were prepared by hydrothermal synthesis.The particle size and potential analysis,electron microscope（TEM,SEM）detection,infrared and XPS analysis and free radical scavenging experiments of CNPs were carried out.The results showed that the prepared CNPs had nano-scale,good dispersion,uniform particle size and certain antioxidant capacity.After that,the macrophage membrane and the nanoparticles were mixed uniformly,and the nanomaterials（MMCNPs）were prepared using a liposome extruder,and the particle size and Zeta potential analysis,transmission electron microscopy and scanning electron microscopy detection,co-localization,protein composition and characterization of surface characteristic proteins were studied.The results showed the cell membrane and nanoparticles are prepared by liposome extruder to obtain nanomaterials MMCNPs with uniform particle size and good dispersion,and it has a typical“core-shell”in situ membrane structure.In addition,the proteins and specific functional proteins on the original macrophage membrane were not damaged,which could be well preserved by MMCNPs.（2）A series of cell-level efficacy verification studies were carried out on the prepared biomimetic nanomaterial MMCNPs.In the experiment of macrophage phagocytosis of nanomaterials in vitro,the amounts of nanoparticles entering macrophages was positively correlated with time,and the uptake of CNPs by macrophages was obviously higher than that of MMCNPs.This result means that the carbon nanomaterials coated by the cell membrane can avoid being excreted by the body as foreign bodies,and can inhibit the uptake of them by macrophages.n the experiment of nanomaterial uptake by inflammatory endothelial cells in vitro,it was found that stimulated endothelial cells can significantly enhance the uptake of CNPs and MMCNPs,but the uptake of MMCNPs was significantly higher than that of CNPs,indicating that carbon nanomaterials could enter more inflammatory endothelial cells after being coated by the membrane.（3）The efficacy and safety of MMCNPs in the treatment of AS were investigated through in vivo animal experiments.After injecting RCNPs and MMRCNPs into the high-fat Apo E^-/-mouse model,24 hours later,the small animals were dissected for fluorescence imaging.It was found that compared with RCNPs alone,the aggregated amount of macrophage membrane-encapsulated MMRCNPs in AS was increased nearly 2-fold,and the accumulation in the liver and kidney was less than that in the RCNPs group.This result indicates that carbon nanomaterials can increase the aggregation amount of nanoparticles in AS after being coated with a membrane,and have a good ability to target the lesions of AS.