关键词: 牙种植体；植入物周围炎；牙髓卟啉单胞菌；β防御素；显微镜检查, 共焦；合成肽；钛表面改性；抗菌肽

Abstract: Abstact: Objective　To explore the bacteriological effects of chemically synthesized peptides on the surface of titanium implants. Methods　A fragment (hBD3-1) derived from human β defensin 3 (hBD3) was chemically combined with peptide TBP-1 to form synthetic peptide TBP-1-hBD3-1. Peptide Calculator software was used to analyze the basic properties of synthetic peptides. The standard micro broth dilution method was used to detect the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of TBP-1-hBD3-1. The microtitration method was used to detect the difference of optical density (OD600) between biofilm control group and biofilm experimental group. Confocal laser scanning microscope (CLSM) experiments was used to further test the bacterial adhesion and bacterial activity on the surface of titanium implants. Results　TBP-1-hBD3-1 showed good solubility, hydrophilicity and hydrophobicity, and had a certain number of positive charges (+4). The MIC and MBC values of TBP-1-hBD3-1 to P. gingivalis were 400 mg/L and 1 000 mg/L, respectively. The OD600 value was significantly lower in the biofilm experimental group than that of the biofilm control group (P＜0.05). The results of CLSM showed that the TBP-1-hBD3-1 labeled blue by AMC could be modified on the surface of titanium plate and exerted antibacterial effect. Conclusion　The synthetic peptide TBP-1-hBD3-1 can be modified on the surface of titanium samples and play an antibacterial and biofilm inhibition effects.

Key words: dental implants, peri-implantitis, Porphyromonas endodontalis, beta-defensins, microscopy, confocal, synthetic peptide, surface modification of titanium, antimicrobial peptide