Cationic amphiphilic bolaamphiphile-based delivery of antisense oligonucleotides provides a potentially microbiome sparing treatment for C. difficile
作者:Arun K. Sharma、Jacek Krzeminski、Volkmar Weissig、John P. Hegarty、David B. Stewart
DOI:10.1038/s41429-018-0056-9
日期:2018.8
Conventional antibiotics for C. difficile infection (CDI) have mechanisms of action without organismal specificity, potentially perpetuating the dysbiosis contributing to CDI, making antisense approaches an attractive alternative. Here, three (APDE-8, CODE-9, and CYDE-21) novel cationic amphiphilic bolaamphiphiles (CABs) were synthesized and tested for their ability to form nano-sized vesicles or vesicle-like aggregates (CABVs), which were characterized based on their physiochemical properties, their antibacterial activities, and their toxicity toward colonocyte (Caco-2) cell cultures. The antibacterial activity of empty CABVs was tested against cultures of E. coli, B. fragilis, and E. faecalis, and against C. difficile by âloadingâ CABVs with 25-mer antisense oligonucleotides (ASO) targeting dnaE. Our results demonstrate that empty CABVs have minimal colonocyte toxicity until concentrations of 71âµM, with CODE-9 demonstrating the least toxicity. Empty CABVs had little effect on C. difficile growth in culture (MIC90ââ¥â160âµM). While APDE-8 and CODE-9 nanocomplexes demonstrated high MIC90 against C. difficile cultures (>300âµM), CYDE-21 nanocomplexes demonstrated MIC90 at CABV concentrations of 19âµM. Empty CABVs formed from APDE-8 and CODE-9 had virtually no effect on E. coli, B. fragilis, and E. faecalis across all tested concentrations, while empty CYDE-21 demonstrated MIC90 of >160âµM against E. coli and >40âµM against B. fragilisand E. faecalis. Empty CABVs have limited antibacterial activity and they can deliver an amount of ASO effective against C. difficile at CABV concentrations associated with limited colonocyte toxicity, while sparing other bacteria. With further refinement, antisense therapies for CDI may become a viable alternative to conventional antibiotic treatment.
常规抗生素用于艰难梭菌感染(CDI)的作用机制缺乏对特定生物的选择性,可能加剧导致CDI的菌群失调,因此使得反义方法成为一种有吸引力的替代方案。本文合成了三种新型阳离子两亲性双头脂质(CABs),即APDE-8、CODE-9和CYDE-21,并测试了它们形成纳米尺寸囊泡或囊泡样聚集体(CABVs)的能力。这些CABVs的物理化学性质、抗菌活性以及对结肠上皮细胞(Caco-2)细胞的毒性进行了表征。研究人员测试了空CABVs对大肠杆菌、脆弱拟杆菌和粪肠球菌以及艰难梭菌的抗菌活性,具体方法是将CABVs装载25聚反义寡核苷酸(ASO),目标是dnaE。结果显示,空CABVs的结肠上皮细胞毒性极低,直至浓度达到71微摩尔,其中CODE-9的毒性最小。空CABVs对艰难梭菌在培养中的生长影响甚微(MIC90≥160微摩尔)。APDE-8和CODE-9纳米复合物对艰难梭菌培养表现出高MIC90(>300微摩尔),而CYDE-21纳米复合物的MIC90在CABV浓度为19微摩尔时出现。APDE-8和CODE-9形成的空CABVs对所有测试浓度下的大肠杆菌、脆弱拟杆菌和粪肠球菌几乎没有影响,而空CYDE-21对大肠杆菌的MIC90为>160微摩尔,对脆弱拟杆菌和粪肠球菌的MIC90为>40微摩尔。空CABVs的抗菌活性有限,但它们能在有限的结肠上皮细胞毒性相关浓度下有效传递ASO以对抗艰难梭菌,同时不影响其他细菌。进一步完善后,针对CDI的反义疗法可能成为传统抗生素治疗的切实替代方案。