Photosensitization of Oral Bacteria

口腔细菌的光敏化

• 批准号: 6546072
• 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/6546072
• 关键词: confocal scanning microscopy; dental plaque; dental research; dentistry; laser therapy; microorganism culture; molecular film; 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）：本研究的总体目标是开发一种临床上有用的方法来增强光敏剂（PS）在人体牙菌斑中的渗透性和有效性，以预防和治疗牙周炎。要测试的假设是：（a）激光产生的光机械波（PW）可以在体外诱导不同密度的口腔细菌生物膜对带正电荷的PS的透化增强，例如聚-L-赖氨酸（p1）和PS二氢卟酚e6（ce6）和阳离子亚甲蓝（MB）之间的聚阳离子缀合物，这种方法可以 显着增加细菌对ce6和MB的摄取，并且(b)这些细菌生物膜在用pl-ce6缀合物和MB致敏并随后暴露于PW和红光之后可能在体外光破坏。 PS 与牙周病原体生物膜的相互作用将使用两种体外模型进行研究：a）附着在天然牙釉质表面上生长的单特异性生物膜，b）在恒化器系统中生长在天然牙釉质表面上的多特异性生物膜。 PS 的吸收将通过测量荧光进行定量，并且它们与细菌的局部相互作用和生物膜基质将通过共焦扫描激光显微镜进行评估。激光诱导的脉冲波将在 PS 存在的情况下应用，以破坏生物膜结构并增加其渗透性。细菌生物膜的其他破坏剂将用于比较。在所有情况下，PS 的渗透性将通过共焦扫描激光显微镜进行评估。在相同的生物膜模型中，将建立 PS 的光动力效应，并评估 PS 对牙周病原菌的 PW 增强光敏作用。