Protoporphyrin-IX conjugated cellulose nanofibers that exhibit high antibacterial photodynamic inactivation efficacy
Protoporphyrin-IX conjugated cellulose nanofibers that exhibit high antibacterial photodynamic inactivation efficacy
复制标题
原卟啉-IX 共轭纤维素纳米纤维具有高抗菌光动力灭活功效
DOI：
10.1088/1361-6528/aabb3c
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发表时间：
2018-06-29
期刊：
影响因子：
3.5
通讯作者：
Wei, Qufu
中科院分区：
文献类型：
--
作者：
Dong, Jiancheng;Ghiladi, Reza A.;Wei, Qufu
为了开发采用光动力作用机制的抗感染纳米材料，我们报道了卟啉缀合的再生纤维素纳米纤维（称为RC-TETA-PPIX-Zn）的合成、物理性质（SEM、机械强度、水接触角）、光谱表征（红外、拉曼、DRUV）以及抗菌功效的评价。醋酸纤维素静电纺丝生产纳米纤维，热处理，以提高机械强度，最后水解生产再生纤维素（RC）纳米纤维，具有高的表面积和纳米纤维结构。用环氧氯丙烷/三亚乙基四胺（TETA）共价接枝原卟啉IX（PPIX）光敏剂，然后进行锌螯合，得到RC-TETA-PPIX-Zn。由纳米纤维提供的高表面积和有效的光敏剂缀合导致412 nmol PPIX/mg材料的非常高的负载，对应于0.1的取代度。针对金黄色葡萄球菌（ATCC-6538）和大肠杆菌（ATCC-8099）评估了抗菌功效，我们的最佳结果在仅20分钟照射（白炽灯，λ ≥ 420 nm）后实现了两种细菌的检测限灭活（99.999+%）。当使用经过5小时预照射的“光老化”纳米纤维来模拟光漂白的效果时，没有观察到抗菌活性的统计学显著损失。在aPDI后，扫描电子显微镜显示细菌经历了细胞膜渗漏，与光生活性氧引起的氧化损伤一致。总之，这里采用的缀合策略提供了一种可扩展的、简便的和有效的途径，以从具有高光敏剂负载的天然聚合物产生纳米纤维材料，使得能够在有效的抗感染纳米材料的设计和合成中使用市售的中性卟啉光敏剂，例如PPIX。
Towards the development of anti-infective nanoscale materials employing a photodynamic mechanism of action, we report the synthesis, physical properties (SEM, mechanical strength, water contact angle), spectroscopic characterization (infrared, Raman, DRUV), and evaluation of antibacterial efficacy of porphyrin-conjugated regenerated cellulose nanofibers, termed RC-TETA-PPIX-Zn. Cellulose acetate was electrospun to produce nanofibers, thermally treated to enhance mechanical strength, and finally hydrolyzed to produce regenerated cellulose (RC) nanofibers that possessed a high surface area and nanofibrous structure. Covalent grafting of a protoporphyrin IX (PPIX) photosensitizer using epichlorohydrin/triethylenetetramine (TETA), followed by zinc chelation, afforded RC-TETA-PPIX-Zn. The high surface area afforded by the nanofibers and efficient photosensitizer conjugation led to a very high loading of 412 nmol PPIX/mg material, corresponding to a degree of substitution of 0.1. Antibacterial efficacy was evaluated against Staphylococcus aureus (ATCC-6538) and Escherichia coli (ATCC-8099), with our best results achieving detection limit inactivation (99.999+%) of both bacteria after only 20 min illumination (Xe lamp, λ ≥ 420 nm). No statistically significant loss in antibacterial activity was observed when using nanofibers that had been ‘photo-aged’ with 5 h of pre-illumination to simulate the effects of photobleaching. Post aPDI, scanning electron microscopy revealed that the bacteria had undergone cell membrane leakage, consistent with oxidative damage caused by photo-generated reactive oxygen species. Taken together, the conjugation strategy employed here provides a scalable, facile and efficient route to creating nanofibrous materials from natural polymers with a high photosensitizer loading, enabling the use of commercially-available neutral porphyrin photosensitizers, such as PPIX, in the design and synthesis of potent anti-infective nanomaterials.