Preparation And Characterization Of Ti₂N Nano-drug Carrier Encapsulated By Cell Membrane

Nano-drug carriers have attracted much attention in the biomedical field because of their characteristics such as targeted recognition,controlled drug release,low side effects and so on.MXenes（Transition metal carbides and nitrides）are emerging as a novel two-dimensional nano materials,which have attracted widespread attention.On the other hand,the erythrocyte membrane has also become a research hotspot due to its high biocompatibility and excellent immune escape ability.In this paper,a cell membrane encapsulated Ti₂N nano-drug carrier was proposed,and its structural characteristics,drug loading and drug release characteristics were studied.And its application prospects in tumor cell therapy was also explored.First,the pure erythrocyte membrane was prepared by hypotonic lysis.And Ti₂N nanosheets with a size of about 300nm were prepared by a method of etching and intercalation,with an obvious single-layer structure.Under laser irradiation,Ti₂N nanosheets exhibited excellent photothermal conversion ability and photothermal stability.On the basis of the above,the erythrocyte membrane was successfully wrapped on the Ti₂N nanosheets by the extrusion method,and a Ti₂N nano-drug carrier wrapped by the erythrocyte membrane was obtained.In order to improve the biocompatibility and stability of Ti₂N nanosheets,Ti₂N-SP nano-drug carriers were obtained by modifying their surfaces with soybean phospholipids.Furthermore,Ti₂N-SP-DOX@RBCM nano-drug carriers were prepared after wrapping the surface of Ti₂N-SP with a red blood cell membrane.Second,using doxorubicin hydrochloride DOX as a drug model,the drug-loading and drug-releasing properties of Ti₂N-SP nano-drug carriers were studied.The experimental results showed that the drug loading rate as high as 382.7%is obtained by virtue of the ultra-high adsorption capacity of Ti₂N.The drug release experiments of Ti₂N-SP-DOX and Ti₂N-SP-DOX@RBCM were carried out under different p H and photothermal conditions,and it was found that the drug release rate increased significantly under low p H and photothermal conditions,which confirmed the nano-drug carrier has dual-responsive drug release properties of p H and photothermal.Finally,we explored the killing potential of the nanodrug carrier on tumor cells.The results of CCK-8 cytotoxicity experiments proved that Ti₂N nano-drug carriers have high photothermal toxicity to breast cancer cells（MCF-7）.The distribution of Ti₂N nano-drug carriers and the release process of DOX in MCF-7 cells were studied by intracellular co-localization experiments.Subsequently,in order to verify the immune evasion ability of nano-drug carriers,Ti₂N nano-drug carriers were co-incubated with murine macrophage RAW264.7 cells.According to the DOX fluorescence intensity and surface morphology in macrophages,it was found that Ti₂N-SP-DOX@RBCM did has the immune evasion ability endowed by erythrocyte membrane and has great potential in the field of tumor therapy.