Preparation And Biocompatibility Of Surface Black Phosphorus Nanosheet Functionalized Titanium Sheets

Titanium has been used in bone and dental implants due to its good biocompatibility as well as mechanical properties,and although hydroxyapatite coating on the surface of titanium facilitates bone regeneration,hydroxyapatite degrades slowly and can not induce bone regeneration rapidly.To further improve the bone regeneration speed of titanium implants,the surface of titanium sheets was modified with better biodegradable black phosphorus nanosheets（BP NSs）.In order to make BP NSs better for bone regeneration,studies on their biocompatibility are necessary.This paper mainly studies the toxicity of BP NSs to MC3T3-E1 cells,and analyzes the reasons for the toxicity of BP NSs to cells.BP NSs were used to modify the surface of titanium,and BP NSs were deposited on the surface of titanium sheets by various methods,and different black phosphorus functionalized coatings were prepared.It conducts research on bone repair.The details are as follows:（1）The bulk black phosphorus was exfoliated into BP NSs by the method of ultrasonic-assisted liquid phase exfoliation,and the BP NSs were prepared by gradient centrifugation.Black phosphorus nanosheets were prepared into different concentrations of BP NSs according to a certain concentration gradient and co-cultured with mouse osteoblast precursor cells MC3T3-E1.The cytotoxicity of BP NSs was studied,and the effect of BP NSs on the mice Causes of toxicity of osteocyte precursor cells MC3T3-E1.（2）A layer of Ti O₂nanotubes was prepared on the surface of Ti by anodizing,and the BP NSs were positively charged by adsorbing Mg²⁺,and the BP NSs were deposited on the Ti containing Ti O₂nanotubes by electrodeposition.Surface,a layer of black phosphorus nanosheet functionalized coating was prepared on the Ti surface,and the biomimetic mineralization of black phosphorus nanosheet functional coating in 1×SBF simulated body fluid was studied and its effect on MC3T3-E1 cells was studied.The results showed that black phosphorus nanosheet coating with bare water leakage on the surface of titanium nanotubes caused obvious toxicity to cells.（3）In order to prepare BP nanosheet coating with stronger bonding strength,chitosan with high bonding strength and good biocompatibility to titanium surface.BP NSs were deposited with chitosan onto the titanium surface by the method of electrodeposition.Ti surface after the alkali heat treatment,CS powder and BP nanosheet solutions were blended and stirred well under acidic conditions,a layer of CS/BP nanosheet coating was prepared by co-depositing CS and BP NSs onto the Ti surface via the electrodeposition method,and the biocompatibility of this coating with MC3T3-E1 was investigated.As a result of the surface,the biocompatibility of chitosan coated black phosphorus nanosheets is still not improved.（4）In order to slowly release BP NSs,hydroxyapatite was introduced in the coating,to enhance the antibacterial properties of hydroxyapatite,the hydroxyapatite was modified with Zn²⁺,and the electrolyte containing Ca²⁺,Zn²⁺,PO₄^3-as well as BP NSs was configured,and the co deposition of three,including Zn²⁺,hydroxyapatite,BP NSs was achieved to prepare the composite coating of BP NSs and Zn²⁺-doped hydroxyapatite,The biocompatibility of this coating with MC3T3-E1 as well as its antibacterial properties were investigated.The results indicated that the hydroxyapatite coated black phosphorus nanosheets had good biocompatibility.