目的 提高钛种植体的生物相容性能和抗菌性能。方法 用多巴胺包覆和表面引发聚合法将季铵化聚乙烯亚胺（QPEI）接枝到酸蚀钛片表面。通过扫描电子显微镜、水接触角测试、X射线光电子能谱（XPS）、激光共聚焦、细胞实验、动物实验等方法，分别评价修饰材料的表面形貌、亲水性、结构、抗菌性、细胞毒性、生物相容性和抗感染性能。结果 聚乙烯亚胺（PEI）上的叔氨基成功转变为季铵基团，通过多巴胺包覆及表面引发聚合的方法均可以在种植体表面成功接枝QPEI，但其抗菌性能和细胞相容性存在差异，通过表面引发聚合进行表面功能化的Ti-PGED-Q组的抗菌性能显著优于通过多巴胺自聚进行功能化的Ti-PDA-Q组，其抑菌率为89.69%。表面引发聚合修饰能影响早期细胞粘附，但对细胞增殖没有显著影响，并显著抑制了带菌种植体造成的体内炎症反应，材料在体内埋植7天时，其表面抑菌率为85.4%，起到良好的抗菌作用。结论 通过原位聚合法对种植体表面进行修饰，可以提高其表面的抗菌性能，并保持良好的生物相容性。

The work aims to improve the biocompatibility and antibacterial properties of titanium implants. Quaternary ammonium polyethyleneimide (QPEI) was grafted onto the surface of titanium by dopamine coating and surface initiated polymerization. The surface morphology, hydrophilicity, structure, antibacterial property, cytotoxicity, biocompatibility and an-ti-infection properties of the modified materials were evaluated by scanning electron microscopy (SEM), water contact angle test, X-ray photoelectron spectroscopy (XPS), confocal Laser Scanning Microscope (CLSM), cell experiments and animal experiments. The tertiary amine groups on polyethyleneimine (PEI) were successfully transformed into quaternary ammonium groups, and QPEI could be successfully grafted onto the implant surface by dopamine coating and surface initiated polymerization, but there were differences in antibacterial properties and cell compatibility. The antibacterial activity (inhibition efficiency = 89.69%) of the Ti-PGED-Q group with surface functionalized through surface initiation polymerization was significantly better than that of the Ti-PDA-Q group functionalized by dopamine self-polymerization. The surface initiation polymerization modification could affect early cell adhesion, but cell proliferation was not markedly affected. Moreover, Ti-PGED-Q did not induce obvious inflammatory reaction in vivo. When the material was planted in vivo for seven days, the surface inhibition efficiency was 85.4%, indicating the good in vivo antibacterial performance. The surface modifcation of the implant by surface initiated polymerization can improve the antibacterial performance and maintain good biocompatibility.