Motivated by the need for self-disinfecting materials that can be used to reduce the surface transmission of harmful microbes to healthy hosts, here we prepared a photodynamic antimicrobial membrane comprised of electrospun cellulose diacetate (CA) microfibers into which the photosensitizer protoporphyrin IX (PpIX) was in situ embedded. The resultant porous PpIX-embedded CA (PpIX/CA) microfibrous membranes were prepared with two different photosensitizer loadings: 5 and 10 wt% PpIX with respect to CA (85 and 170 nmol PpIX/mg membrane, respectively). The singlet oxygen (¹O₂) generated by the embedded photosensitizer was confirmed by electron paramagnetic resonance spectroscopic studies through generation of the TEMPO radical, and its photooxidation efficiency was further investigated using potassium iodide as a model substrate. Antibacterial photodynamic inactivation studies showed that the PpIX/CA membrane achieved a 99.8% reduction in Gram-positive S. aureus after illumination (Xe lamp, 65 ± 5 mW/cm², λ ≥ 420 nm; 30 min), with a lower level of reduction (86.6%) for Gram-negative E. coli. Potentiation with potassium iodide was found to be an effective way to further enhance the antimicrobial efficacy of the PpIX/CA microfibrous membrane, achieving 99.9999% (6 log units) inactivation of both S. aureus and E. coli in the presence of 25 and 100 mM KI, respectively. These findings indicate that the electrospun CA microfibrous membrane is an ideal matrix for a photosensitizer such as PpIX to be embedded and effectively sensitized upon visible light illumination, and its antimicrobial photodynamic inactivation efficiency could be strongly enhanced with the increased KI addition, showing a promising future for its use in pathogen transmission defensive materials.

出于对可用于减少有害微生物向健康宿主表面传播的自我消毒材料的需求的激励，我们在这里制备了一种由电纺纤维素二乙酸酯（CA）微纤维组成的光动力抗菌膜，光敏剂原卟啉IX（PpIX）进入其中在原位嵌入。用两种不同的光敏剂负载制备所得的包埋有PpIX的多孔CA（PpIX / CA）微纤维膜：相对于CA分别为5和10 wt％PpIX（分别为85和170 nmol PpIX / mg膜）。单线态氧（¹ O ₂通过电子顺磁共振波谱研究通过生成TEMPO自由基来确认由嵌入的光敏剂产生的），并使用碘化钾作为模型底物进一步研究了其光氧化效率。抗菌光动力灭活研究表明，PpIX / CA膜在照射（Xe灯，65±5 mW / cm ²，λ≥420 nm； 30分钟）后，革兰氏阳性金黄色葡萄球菌减少了99.8％。革兰氏阴性大肠杆菌的减少量（86.6％）。发现用碘化钾增强是进一步增强PpIX / CA微纤维膜的抗菌功效的有效方法，实现了两种金黄色葡萄球菌的灭活99.9999％（6个对数单位）。分别在25和100 mM KI的存在下接种大肠杆菌和大肠杆菌。这些发现表明，电纺CA微纤维膜是光敏剂如PpIX的理想基质，可在可见光照射下嵌入并有效增敏，并且随着KI添加量的增加，其抗菌光动力失活效率将大大提高，显示出有希望的未来用于病原体传播防御材料。