基于木质素自组装的万古霉素纳米载药系统构建与抗菌性能评价

Construction and antibacterial evaluation of vancomycin-loaded lignin self-assembled nano-drug delivery system

摘要

目的: 构建负载万古霉素的木质素自组装纳米递药系统,并评估其体外抗菌性能及生物相容性。方法: 通过自组装法制备木质素纳米载体并负载万古霉素,采用动态光散射(dynamic light scattering,DLS)和透射电子显微镜(transmission electron microscopy,TEM)表征纳米粒的粒径与形貌,质谱仪测定载药量、包封率及药物释放行为;以金黄色葡萄球菌为模型菌株,通过微量二倍稀释法测定抗菌活性;结合平板涂布法、结晶紫染色、活/死细菌染色及细菌扫描电镜(scanning electron microscopy,SEM),分析纳米粒对细菌生物膜及细胞膜的破坏作用;采用CCK-8法检测纳米粒对HeLa细胞的生物相容性。结果: 成功制备粒径约100 nm且分布均匀的木质素-万古霉素纳米复合物,其在弱酸性环境(pH=5.5)中表现出更快的药物释放速率。抗菌实验显示,该纳米粒能有效破坏细菌生物膜结构及细胞膜完整性。CCK-8实验证实其具有良好的生物相容性,具备进一步体内研究的潜力。结论: 木质素自组装纳米递药系统可高效负载并缓释万古霉素,通过破坏细菌膜结构增强抗菌效果,且安全性良好,为细菌感染治疗提供了新型候选策略。

Abstract

Objective: To construct a lignin-based self-assembled nanodrug delivery system loaded with vancomycin and evaluate its in vitro antibacterial performance and biocompatibility. Methods: Vancomycin-loaded lignin nanoparticles (NPs) were prepared via self-assembly. The particle size and morphology were characterized using dynamic light scattering (DLS) and transmission electron microscopy (TEM), while drug loading capacity, encapsulation efficiency, and release profile were determined by mass spectrometry. Staphylococcus aureus was used as a model strain to assess antibacterial activity via the microdilution broth method. The antibacterial mechanisms, including biofilm disruption and membrane damage, were investigated through colony counting, crystal violet staining, live/dead bacterial staining, and scanning electron microscopy (SEM). Biocompatibility was evaluated using the CCK-8 assay on HeLa cells. Results: Uniform lignin-vancomycin nanocomposites (~100 nm) were successfully prepared. The NPs exhibited pH-responsive drug release, with faster release under weakly acidic conditions (pH=5.5). Antibacterial tests demonstrated effective biofilm destruction and bacterial membrane disruption. CCK-8 assays confirmed excellent biocompatibility, supporting potential in vivo applications. Conclusion: The lignin-based self-assembled nanocarrier efficiently loads and sustains vancomycin release, enhances antibacterial efficacy via membrane-targeting mechanisms, and shows favorable biosafety. This system provides a promising strategy for treating bacterial infections.

关键词

木质素 / 万古霉素 / 自组装纳米粒 / 细菌感染 / 体外抗菌

Key words

lignin / vancomycin / self-assembled nanoparticles / antimicrobial resistance / in vitro antibacterial