Maaßen Isabel Katharina, Luther Anne-Marie, Varzandeh Mohammad, Hackbarth Steffen, Waberski Dagmar
Unit for Reproductive Medicine/Clinic for Swine and Small Ruminants, University of Veterinary Medicine Hannover, 30559 Hannover, Germany.
Photobiophysics, Institute of Physics, Humboldt University of Berlin, 10117 Berlin, Germany.
Microorganisms. 2025 Mar 12;13(3):643. doi: 10.3390/microorganisms13030643.
The photodynamic inactivation (PDI) of bacteria is a promising alternative to antibiotics in boar semen extenders. It was recently established using the illumination of semen samples containing 2 µM of the photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) with white LED light. High concentrations of TMPyP require strict sample handling in the dark to avoid uncontrolled photodynamic effects caused by ambient light. This study was designed to examine whether lower concentrations of PS could be utilized along with a narrow band blue LED light source, which aligns with TMPyP's Soret band, thereby minimizing light-induced disruption. A dose-response study with blue LED light exposure of sperm revealed no light toxicity. Importantly, substituting the established white light PDI with blue light illumination and 0.5 µM TMPyP resulted in robust antimicrobial efficiency and sperm compatibility in long-term stored semen samples. This modification led to the confirmation of the hypothesis that a diminished TMPyP concentration in concert with blue LED light facilitates semen handling in normal laboratory light while avoiding unintended light effects. In conclusion, this study plays a pivotal role in augmenting the practicality of the innovative PDI technology by establishing a method that is less susceptible to unanticipated effects of ambient light during sample management.
细菌的光动力灭活（PDI）是公猪精液稀释剂中抗生素的一种有前景的替代方法。最近通过用白色LED灯照射含有2 µM光敏剂5,10,15,20-四（N-甲基-4-吡啶基）-21H，23H-卟啉（TMPyP）的精液样本得以实现。高浓度的TMPyP需要在黑暗中进行严格的样本处理，以避免环境光引起的不受控制的光动力效应。本研究旨在检验较低浓度的光敏剂是否可以与窄带蓝色LED光源一起使用，该光源与TMPyP的Soret带相匹配，从而将光诱导的破坏降至最低。对精子进行蓝色LED光照射剂量反应研究未发现光毒性。重要的是，用蓝光照射和0.5 µM TMPyP替代已确立的白光PDI，在长期储存的精液样本中产生了强大的抗菌效率和精子兼容性。这一改进证实了以下假设：降低TMPyP浓度并结合蓝色LED光，有利于在正常实验室光照下处理精液，同时避免意外的光效应。总之，本研究通过建立一种在样本管理过程中对环境光意外影响不太敏感的方法，在提高创新PDI技术的实用性方面发挥了关键作用。
