Photosensitization of Oral Bacteria

口腔细菌的光敏化

• 批准号: 6659012
• 负责人: NIKOLAOS SOUKOS
• 金额: $ 28.94万
• 依托单位: ADA FORSYTH INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-15 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6659012
• 关键词: biofilm; confocal scanning microscopy; dental plaque; dental research; dentistry; laser therapy; microorganism culture; oral bacteria; periodontitis; photoactivation; photosensitizing agents; polylysine; tooth enamel; transmission electron microscopy

DESCRIPTION (provided by applicant): The overall goal of this research is to develop a clinically useful way to enhance the penetration and effectiveness of photosensitizers (PS) in human Dental plaque for prevention and treatment of periodontitis. The hypotheses to be tested are: (a) Laser-generated photomechanical waves (PW) can induce in vitro enhanced permeabilization of oral bacterial biofilms of different density to positively charged PS, such as a polycationic conjugate between poly-L-lysine (p1) and the PS chlorin e6 (ce6) and the cationic methylene blue (MB), an approach which can significantly increase uptake of ce6 and MB by bacteria, and (b) Photodestruction of these bacterial biofilms in vitro may be possible after their sensitization with the pl-ce6 conjugate and MB followed by exposure to PW and red light. The interaction of the PS with biofilms of periodontopathogens will be studied using two in vitro models: a) monospecific biofilms growing attached to natural enamel surfaces, and b) multispecific biofilms growing on natural enamel surfaces in a chemostat system. The uptake of PS will be quantitated by measuring fluorescence and their local interaction with bacteria and the biofilm matrix will be evaluated by confocal scanning laser microscopy. Laser-induced PW will be applied in the presence of the PS to disorganize the biofilm structure and increase their penetration. Other disorganizing agents of the bacterial biofilm will be used for comparisons. In all cases, the penetration of the PS will be evaluated by confocal scanning laser microscopy. In the same biofilm models the photodynamic effects of the PS will be established and PW-enhanced photosensitization of periodontopathogens by the PS will be evaluated.

描述（由申请人提供）：这项研究的总体目标是开发一种临床上有用的方法，以增强光敏剂（PS）在人类牙齿斑块中的渗透和有效性，以预防和治疗牙周炎。 The hypotheses to be tested are: (a) Laser-generated photomechanical waves (PW) can induce in vitro enhanced permeabilization of oral bacterial biofilms of different density to positively charged PS, such as a polycationic conjugate between poly-L-lysine (p1) and the PS chlorin e6 (ce6) and the cationic methylene blue (MB), an approach which can通过细菌显着增加CE6和MB的摄取，（b）在对PL-CE6偶联物和MB的敏化后，可能会在体外对这些细菌生物膜的摄取，然后可能会暴露于PW和PW和红光下。 将使用两个体外模型研究PS与牙周病原子生物膜的相互作用：a）生长在天然搪瓷表面附着的单特异性生物膜，b）在化学仪表体系统中生长在天然搪瓷表面上的多特异性生物膜。 PS的摄取将通过测量荧光和局部与细菌的局部相互作用来定量，并且将通过共聚焦扫描激光显微镜评估生物膜基质。激光诱导的PW将在PS存在的情况下应用，以使生物膜结构混乱并增加其穿透性。细菌生物膜的其他混乱剂将用于比较。在所有情况下，PS的穿透都将通过共聚焦扫描激光显微镜评估。在相同的生物膜模型中，将评估PS的PS的光动力效应，并通过PS对PW增强的光敏作用。