Targeted Inactivation of Bacteriophages by Polypyrrole Nanoparticles

Bacteriophage contamination is a persistent issue in various industrial and medical settings, requiring effective yet selective inactivation strategies. The source of phages may be antibiotics, other additives, or raw substrates. There are no effective methods to protect bacterial cultures against such events. This study proposes polypyrrole nanoparticles functionalized with 1% carboxyl groups (P(Py:PyCOOH) 100:1 NPs) as a targeted solution for phage inactivation. The P(Py:PyCOOH) 100:1 nanoparticles exhibit selective antiviral properties, with above 95% inactivation of T4, MS2, and vB_SauS_CS1 phages, while maintaining less than 5% inactivation of their corresponding bacterial hosts (E. coli and S. aureus). TEM imaging reveals no significant morphological changes in the phages post-treatment, suggesting that inactivation occurs through blocking active sites rather than structural damage. Cytotoxicity studies demonstrate >90% viability of 3T3 NIH fibroblast cells upon exposure to P(Py:PyCOOH) 100:1, confirming the nanoparticles' biocompatibility and safety for potential biomedical applications. Because some phages serve as surrogates for pathogenic viruses, the presented results are the next step towards selective and safe antivirals acting directly on virions.

噬菌体（bacteriophage）污染在各类工业与医疗场景中均为长期存在的棘手问题，亟需兼具高效性与选择性的灭活策略。噬菌体的污染源可能涵盖抗生素、其他添加剂或原辅料。目前尚无有效手段可保护细菌培养体系免受此类污染的侵扰。本研究提出经1%羧基官能化修饰的聚吡咯（polypyrrole）纳米颗粒（P(Py:PyCOOH) 100:1 NPs）作为靶向性噬菌体灭活解决方案。该P(Py:PyCOOH) 100:1纳米颗粒展现出选择性抗病毒活性：对T4、MS2及vB_SauS_CS1三种噬菌体的灭活率均超过95%，而对其对应的宿主菌——大肠杆菌（E. coli）与金黄色葡萄球菌（S. aureus）的灭活率则低于5%。透射电子显微镜（Transmission Electron Microscopy, TEM）成像结果显示，经处理后的噬菌体未出现显著形态学变化，提示其灭活机制为阻断活性位点，而非破坏噬菌体结构。细胞毒性实验结果表明，3T3 NIH成纤维细胞暴露于P(Py:PyCOOH) 100:1纳米颗粒后，存活率仍高于90%，证实该纳米颗粒具备良好的生物相容性与应用安全性，可用于潜在的生物医学场景。鉴于部分噬菌体可作为致病性病毒的替代模型，本研究成果为研发直接作用于病毒体（virion）的选择性安全抗病毒制剂迈出了关键的探索性一步。