Abstract

Antibacterial photodynamic therapy (APDT) is a promising method of treatment of local infections, based on photochemical reaction of photosensitizer (PS) under irradiation with visible or near infra-red light of appropriate wavelength. A molecule of PS is activated by light energy and as a result singlet oxygen and other reactive oxygen species, which are toxic for microbes, are generated. Antibacterial action of new PS (synthetic polycationic bacteriochlorin derivatives with spectral maximum of absorbance at 760 nm) with improved features was investigated in vitro in this work. Tetra- and octacationic bacteriochlorins with lower molecular mass, as compared with ones previously proposed, turned out to be highly effective against Pseudomonas aeruginosa and Staphylococcus aureus in plankton and biofilm state: reduction of viable bacteria in biofilms reached 5log₁₀. The dependence of the effect on PS concentration, the time of incubation with PS and light dose was ascertained. Light microscopy of biofilms after photodynamic treatment and Live/Dead staining confirmed the death of bacteria or damage of their membranes after exposure to PS and irradiation.

中文翻译：

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合成阳离子细菌氯霉素衍生物作为光敏剂的抗菌性能

摘要

抗菌光动力疗法（APDT）是一种有前途的治疗局部感染的方法，它基于光敏剂（PS）在可见光或近红外光的适当波长照射下的光化学反应。PS分子被光能激活，结果产生了对微生物有毒的单线态氧和其他活性氧。在这项工作中，对具有改进功能的新型PS（具有760nm吸光度最大光谱的合成聚阳离子细菌氯霉素衍生物）的抗菌作用进行了研究。与先前提出的相比，具有较低分子量的四阳离子和八阳离子细菌绿素被证明对铜绿假单胞菌和金黄色葡萄球菌非常有效。处于浮游生物和生物膜状态：生物膜中活菌的减少达到5log ₁₀。确定了对PS浓度的影响，与PS一起温育的时间和光剂量的依赖性。光动力处理和活/死染色后，对生物膜的光学显微镜检查证实了暴露于PS和辐射后细菌的死亡或膜的损坏。