Maisch Tim, Szeimies Rolf-Markus, Jori Giulio, Abels Christoph
Department of Dermatology, University of Regensburg, Germany.
Photochem Photobiol Sci. 2004 Oct;3(10):907-17. doi: 10.1039/b407622b. Epub 2004 Sep 16.
Photodynamic therapy (PDT) appears to be endowed with several favourable features for the treatment of localized microbial infections, especially after the advent of cationic photosensitising agents (phenothiazines, meso-substituted porphyrins, polylysine-bound chlorins) which properly interact with the outer wall at the surface of several types of bacterial and yeast cells, increase their permeability, and allow significant amounts of photosensitizer to be accumulated at the level of the cytoplasmic membrane. These photosensitisers are characterized by a broad spectrum of activity, being effective toward both wild strain and antibiotic-resistant gram-positive and gram-negative bacteria and yeasts. In general, extensive eradication of pathogens can be achieved under mild irradiation conditions, such as short incubation times and low fluence-rates, which guarantees a high degree of selectivity in comparison with the main constituents of host tissues, such as keratinocytes and fibroblasts. Moreover, the photosensitised inactivation of microorganisms is typically a multi-target process; as a consequence, the selection of photoresistant microbial strains is very unlikely and has not been experimentally observed so far. Possible initial targets of antimicrobial PDT applications include periodontal diseases, impetigo, atopic dermatitis, acne vulgaris, infected wounds, and superinfected posriatic plaques.
光动力疗法（PDT）似乎具有治疗局部微生物感染的几个有利特性，特别是在阳离子光敏剂（吩噻嗪、中位取代卟啉、聚赖氨酸结合二氢卟酚）出现之后，这些光敏剂能与几种细菌和酵母细胞表面的外壁发生适当相互作用，增加其通透性，并使大量光敏剂在细胞质膜水平积累。这些光敏剂具有广泛的活性谱，对野生菌株以及耐抗生素的革兰氏阳性和革兰氏阴性细菌及酵母均有效。一般来说，在温和的辐照条件下，如短孵育时间和低光通量率，就能实现病原体的广泛根除，与宿主组织的主要成分如角质形成细胞和成纤维细胞相比，这保证了高度的选择性。此外，微生物的光敏失活通常是一个多靶点过程；因此，选择抗光微生物菌株的可能性极小，而且迄今为止尚未在实验中观察到。抗菌PDT应用的可能初始靶点包括牙周疾病、脓疱病、特应性皮炎、寻常痤疮、感染伤口和银屑病斑块的继发感染。
