一种pH响应性纳米粒对牙周菌斑生物膜的抑制作用及生物相容性评价

INHIBITORY EFFECT OF PH-RESPONSIVE NANOPARTICLES ON PERIODONTAL PLAQUE BIOFILM AND ITS BIOCOMPATIBILITY EVALUATION

目的制备具有pH响应性的复合纳米粒,初步探讨其对3种牙周常见致病菌的体外抑菌活性、对牙周膜成纤维细胞的细胞相容性及其体内毒性。方法以壳聚糖、卵磷脂、多西环素、碘甲烷等为原料,通过薄膜分散法,正负电荷吸附法制备具有pH响应性的季铵盐脂质体多西环素纳米粒(TMC-Lip-DOX NPs),采用透射电镜(TEM)观察其形态,采用激光粒度/Zeta电位分析仪测定其粒径、分散度(PDI)和Zeta电位,采用牙龈卟啉单胞菌、中间普氏菌和伴放线放线杆菌研究其对游离混合菌和菌斑生物膜的体外抑菌活性,采用牙周膜成纤维细胞(HPDLFs)进行细胞相容性研究,最后采用大鼠灌胃实验评价其体内急性毒性。结果 TMC-Lip-DOX NPs在水溶液中分散均匀,近似圆形,PDI为0.22,粒径为172nm,Zeta电位为13.35mV。其对于混合游离菌及其菌斑生物膜的形成具有较好的抑制作用。MTT实验结果显示,不同浓度的TMC-Lip-DOX NPs与细胞分别作用24以及48h后,细胞活力均大于80%。灌胃实验显示,大鼠各内脏病理结果无明显异常改变,所制备的TMC-Lip-DOX NPs无明显毒性作用。结论实验中成功制得的TMC-Lip-DOX NPs粒径较小,具有较强的抑菌作用,毒性小,大大提高了抗生素在体内的作用效率,从而有助于减少临床中抗生素的滥用,具有广泛的应用前景。

Objective To prepare pH-responsive composite nanoparticles(NPs)and to investigate its in vitro antimicrobial activity against three common periodontal pathogens,cytocompatibility with human periodontal ligament fibroblasts(HP-DLFs)in vitro,and in vivo toxicity.Methods The pH-responsive composite trimethyl chitosan liposomal doxycycline nanopar-ticles(TMC-Lip-DOX NPs)were prepared with chitosan,lecithin,doxycycline,and methyliodide by thin-film dispersion method and positive and negative charge adsorption method.The morphology was observed by a transmission electron microscope.The particle size,dispersity(PDI),and Zeta potential were measured by laser particle size analy zerand Zeta potential analyzer.The in vitro antimicrobial activity of the NPs against mixed free bacteria and plaque biofilm was evaluated using Porphyromonas gingivalis,Prevotella intermedia,and Actinobacillus actinomy cetemcomitans.The cytocompatibility of the NPs was measured by MTT assay using HPDLFs as themodel.Theinvivoacutetoxicity wasevaluatedby intragastric administrationinrats.TMC-Lip-DOX NPswereuniformlydispersedin an aqueoussolution andwere approximately circularwitha PDIof0.22,aparticlesize of 172 nm,and a Zetapotentialof丄3.35mV.TheNPs had a goodinhibitoryeffecton themixedfreebacteriaandplaque biofilmfor-mation.MTT assay results showed that cell viability was more than 80%at 24 and 48hours after treatment with different concen trations of TMC-Lip-DOX NPs.The results of intragastric administration showed that there were no significant changes in pathological results of the visceral organs of rats.The prepared TMC-Lip-DOX NPs in this study had no significant toxic effect.Conclusion TMC-Lip-DOX NPs can be successfully prepared in this study.They have small particle size,potent antimicrobial activity,and low toxicity,which greatly improve the efficiency of antibio-tics in the body,thereby helping reduce the misuse of antibiotics.Therefore,they hold promise for clinical application.