Dai Tianhong, Tegos George P, Zhiyentayev Timur, Mylonakis Eleftherios, Hamblin Michael R
Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
Lasers Surg Med. 2010 Jan;42(1):38-44. doi: 10.1002/lsm.20887.
Methicillin-resistant Staphylococcus aureus (MRSA) skin infections are now known to be a common and important problem in the Unites States. The objective of this study was to investigate the efficacy of photodynamic therapy (PDT) for the treatment of MRSA infection in skin abrasion wounds using a mouse model.
STUDY DESIGN/MATERIALS AND METHODS: A mouse model of skin abrasion wound infected with MRSA was developed. Bioluminescent strain of MRSA, a derivative of ATCC 33591, was used to allow the real-time monitoring of the extent of infection in mouse wounds. PDT was performed with the combination of a polyethylenimine (PEI)-ce6 photosensitizer (PS) and non-coherent red light. In vivo fluorescence imaging was carried out to evaluate the effect of photobleaching of PS during PDT.
In vivo fluorescence imaging of conjugate PEI-ce6 applied in mice indicated the photobleaching effect of the PS during PDT. PDT induced on average 2.7 log(10) of inactivation of MRSA as judged by loss of bioluminescence in mouse skin abrasion wounds and accelerated the wound healing on average by 8.6 days in comparison to the untreated infected wounds. Photobleaching of PS in the wound was overcome by adding the PS solution in aliquots.
PDT may represent an alternative approach for the treatment of MRSA skin infections.
耐甲氧西林金黄色葡萄球菌（MRSA）皮肤感染如今在美国已成为一个常见且重要的问题。本研究的目的是使用小鼠模型研究光动力疗法（PDT）治疗皮肤擦伤伤口中MRSA感染的疗效。
研究设计/材料与方法：建立了感染MRSA的皮肤擦伤伤口小鼠模型。使用MRSA的生物发光菌株（ATCC 33591的衍生物）来实时监测小鼠伤口的感染程度。采用聚乙烯亚胺（PEI）-ce6光敏剂（PS）与非相干红光联合进行光动力疗法。进行体内荧光成像以评估光动力疗法期间PS的光漂白效果。
对小鼠应用共轭PEI-ce6的体内荧光成像表明了光动力疗法期间PS的光漂白效果。根据小鼠皮肤擦伤伤口生物发光的丧失判断，光动力疗法平均使MRSA失活2.7个对数（10），与未治疗的感染伤口相比，平均加速伤口愈合8.6天。通过分份添加PS溶液克服了伤口中PS的光漂白。
光动力疗法可能是治疗MRSA皮肤感染的一种替代方法。
