血卟啉单甲醚介导的声动力疗法对菌斑细菌生物膜作用效果的研究

Effect of sonodynamic therapy with hematoporphyrin monomethyl ether on plaque bacterial biofilm

目的探讨由超声(ultrasound,US)联合声敏剂血卟啉单甲醚(hematoporphyrin monomethyl ether,HMME)产生的声动力疗法(sonodynamic therapy,SDT)对菌斑细菌生物膜活性、膜结构的影响。方法采集牙周炎患者牙菌斑细菌样本,在37℃、厌氧(85%N2、10%CO2、5%H2)培养。分组:①HMME最小抑菌浓度:选取浓度为0、10、20、30、40、50、60 mg/L的HMME共分成7组;②SDT疗效:Control组、HMME组(50 mg/L为最小抑菌浓度)、US组、SDT组。检测:牙菌斑中细菌在超声强度为3 W/cm2、时间为5 min时HMME的最小抑菌浓度;在SDT作用下牙菌斑的菌落形成单位(colony⁃forming units,CFU);平板计数法检测细菌的存活率;菌斑细菌生物膜活性及形态结构的变化。结果①当超声作用强度为3 W/cm2、5 min时,作为声敏剂的HMME最小抑菌浓度为50 mg/L,剂量-效应关系显著(P<0.05)。②在细菌生物膜存活率比较中,SDT组远低于其他组(P<0.05)。③相比于Control组菌斑细菌边缘清晰、细菌集聚、管状结构完好的形态,SDT组的菌斑细菌边缘破坏、散在分布、结构不再完整。④SDT组的菌斑细菌生物膜相比于Control组、HMME组、超声(ultrasound,US)组可见死菌占比大。结论SDT对菌斑细菌生物膜有一定的抑菌作用,在抑菌的过程中死菌比例增加,并破坏细菌生物膜的结构,产生杀伤效果。

Objective To explore the influence of Sonodynamic therapy(SDT)produced by ultrasound(US)combined with the sensitizer hematoporphyrin monomethyl ether(HMME)on biological activity and membrane structured of dental plaque bacterial bio⁃film.Methods Bacterial samples from patients with periodontitis were collected and incubated at 37℃,anaerobic(85%N2,10%CO2,5%H2)environment.Grouping:①HMME minimum inhibitory concentration:HMME with concentration 0 mg/L,10 mg/L,20 mg/L,30 mg/L,40 mg/L,50 mg/L,60 mg/L were divided into 7 groups;②SDT efficacy:Control groups,HMME groups(50 mg/L,minimum inhibitory concentration),US groups,SDT groups.Detection:The minimum inhibitory concentration of HMME in dental plaque at the ultrasonic intensity of 3 W/cm2 for 5 min;colony⁃forming units(CFU)of dental plaque under SDT;the survival rate of bacteria detected with plate count method;the activity of plaque bacterial biofilm;the change of morphological structure.Results①When the intensity of ultrasound was 3 W/cm2,lasting for 5 min,the minimum inhibitory concentration of HMME as a sound sensitizer was 50 mg/L,and the dose⁃effect relationship was significant(P<0.05).②In the comparison of bacterial biofilm survival rate,the SDT groups were much lower than the other groups(P<0.05).③Compared with the morphology of the plaque bacteria in the control groups,in which the bacteria were concentrated and the tubular structure was intact,the plaque bacteria in the SDT groups were damaged,scattered,and the structure was incomplete.④Compared with Control groups,HMME groups and US groups,the plaque bacterial biofilm in SDT groups had a larger proportion of dead bacteria.Conclusion SDT has a certain bacteriostatic effect on plaque bacterial biofilm.During the process of bacteriostasis,the proportion of dead bacteria increases,and the structure of bacterial biofilm is destroyed,resulting in a killing effect.