Skwor Troy A, Klemm Stephanie, Zhang Hanyu, Schardt Brianna, Blaszczyk Stephanie, Bork Matthew A
Rockford University, Department of Chemical and Biological Sciences, 5050 E. State St., Rockford, IL 61108, USA; University of Illinois - Chicago at Rockford, College of Medicine, 1601 Parkview Ave., Rockford, IL 61107, USA.
Rockford University, Department of Chemical and Biological Sciences, 5050 E. State St., Rockford, IL 61108, USA.
J Photochem Photobiol B. 2016 Dec;165:51-57. doi: 10.1016/j.jphotobiol.2016.10.016. Epub 2016 Oct 15.
Increasing rates of antibiotic resistance coupled with the lack of novel antibiotics threatens proper clinical treatment and jeopardizes their use in prevention. A photodynamic approach appears to be an innovative treatment option, even for multi-drug resistant strains of bacteria. Three components are utilized in photodynamic inactivation: a photosensitizer, light source, and oxygen. Variations in photosensitizers strongly influence microbial binding and bactericidal activity. In this study, four different cationic metalloporphyrins (Cu, Fe, Pd, Zn) were compared to the free-base ligand 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin regarding their electronic properties and generation of reactive oxygen species upon subsequent 405nm violet-blue irradiation. Staphylococcus aureus and Escherichia coli were used as representatives of Gram-positive and -negative, respectively, to assess bactericidal effects by the photodynamic process. Bacterial cultures were pre-incubated with porphyrins and exposed to varying doses of 405nm irradiation (0-30J/cm). Metalloporphyrins containing Cu and Fe demonstrated minimal effects on viability. Pronounced bactericidal activity was evident with free-base ligand, Zn, and Pd; though significantly stronger effects were apparent with Pd. Photodynamic killing was directly proportional to reactive oxygen species production post-illumination. These data provide new insight into the influence of metal chelation on photosensitizer activity on bactericidal singlet oxygen production. The strong anti-microbial photodynamic action through the use of a portable light-emitting diode over short time intervals (seconds) provides support for its potential use in self-treatment.
抗生素耐药率的不断上升，再加上新型抗生素的匮乏，威胁到了恰当的临床治疗，并危及它们在预防方面的应用。光动力疗法似乎是一种创新的治疗选择，即使对于多重耐药菌株也是如此。光动力失活利用三种成分：光敏剂、光源和氧气。光敏剂的变化强烈影响微生物结合和杀菌活性。在本研究中，将四种不同的阳离子金属卟啉（铜、铁、钯、锌）与游离碱配体5,10,15,20-四（N-甲基吡啶-4-基）卟啉在电子性质以及随后405nm紫蓝光照射后活性氧生成方面进行了比较。金黄色葡萄球菌和大肠杆菌分别作为革兰氏阳性菌和阴性菌的代表，用于评估光动力过程的杀菌效果。细菌培养物先用卟啉预孵育，然后暴露于不同剂量的405nm照射（0-30J/cm）下。含铜和铁的金属卟啉对生存能力的影响最小。游离碱配体、锌和钯表现出明显的杀菌活性；不过钯的杀菌效果明显更强。光动力杀伤与光照后活性氧的产生成正比。这些数据为金属螯合对光敏剂活性及杀菌单线态氧产生的影响提供了新的见解。通过使用便携式发光二极管在短时间间隔（数秒）内产生的强大抗菌光动力作用，为其在自我治疗中的潜在应用提供了支持。
