PDF(Pubmed)
Abstract：
Photodynamic therapy (PDT) is an important technique to deal with drug-resistant bacterial infections in the post-antibiotic era. However, the hypoxic environment in intractable infections such as refractory keratitis and periodontitis, makes PDT more difficult. In this work, spontaneous oxygen-producing cyanobacteria were used as the carrier of photosensitizer (Ce6), and ultrasmall Cu5.4O nanoparticles (Cu5.4O USNPs) with catalase activity for infection and inflammation elimination and rapid tissue repair (CeCycn-Cu5.4O). The loading of Ce6 and Cu5.4O USNPs onto cyanobacteria surface were confirmed by transmission electron microscopy, nano particle size analyzer, scanning electron microscopy. In vitro sterilization and biofilm removal experiments demonstrated that the restriction of hypoxic environment to PDT was significantly alleviated due to the oxygen production of cyanobacteria. Under laser irradiation, the close transfer of energy photons to oxygen produced by cyanobacteria reduced more than 90% of Ce6 dosages (660 nm, 200 mW/cm2, 2 min). It is worth mentioning that both rapid sterilization through PDT and long-term oxidized free radicals elimination were achieved by adjusting the ratio of Ce6 and Cu5.4O USNPs. Both periodontitis and refractory keratitis animal models proved the excellent self-oxygenation enhanced antibacterial property and promotion of tissue repair.
摘要：
光动力疗法（PDT）是后抗生素时代应对耐药细菌感染的重要技术。然而,难治性感染如难治性角膜炎和牙周炎的缺氧环境，使PDT更加困难。在这项工作中,自发产氧蓝细菌被用作光敏剂（Ce6）的载体，和具有过氧化氢酶活性的超小Cu5.4O纳米颗粒（Cu5.4OUSNPs），用于感染和炎症消除以及快速组织修复（CeCycn-Cu5.4O）。通过透射电子显微镜证实了Ce6和Cu5.4OUSNPs在蓝藻表面的负载，纳米粒度分析仪，扫描电子显微镜。体外灭菌和生物膜去除实验表明，由于蓝藻的氧气产生，低氧环境对PDT的限制得到了显着缓解。在激光照射下，能量光子向蓝细菌产生的氧气的紧密转移减少了90%以上的Ce6剂量(660nm，200mW/cm2,2min)。值得一提的是，通过调整Ce6和Cu5.4OUSNPs的比例，实现了通过PDT的快速灭菌和长期氧化自由基的消除。牙周炎和难治性角膜炎动物模型均证明了良好的自氧增强抗菌性能和促进组织修复。
