Singh Ravi, Al-Jamal Khuloud T, Lacerda Lara, Kostarelos Kostas
Nanomedicine Laboratory, Centre for Drug Delivery Research, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom.
ACS Nano. 2008 May;2(5):1040-50. doi: 10.1021/nn8000565.
We have developed a novel, reproducible, and facile methodology for the construction of artificial lipid envelopes for adenoviruses (Ad) by self-assembly of lipid molecules around the viral capsid. No alteration of the viral genome or conjugation surface chemistry at the virus capsid was necessary, therefore difficulties in production and purification associated with generating most surface-modified viruses can be eliminated. Different lipid bilayer compositions produced artificially enveloped Ad with physicochemical and biological characteristics determined by the type of lipid used. Physicochemical characteristics such as vector size, degree of aggregation, stability, and surface charge of the artificially enveloped Ad were correlated to their biological (gene transfer) function. In monolayer cell cultures, binding to the coxsackie and adenovirus receptor (CAR) was blocked using a zwitterionic envelope, whereas enhanced binding to the cell membrane was achieved using a cationic envelope. Envelopment of Ad by both zwitterionic and cationic lipid bilayers led to almost complete ablation of gene expression in cell monolayers, due to blockage of virion endosomal escape. Alternatively, artificial Ad envelopes built from lipid bilayers at the fluid phase in physiological conditions led to enhanced penetration of the vectors inside a three-dimensional tumor spheroid cell culture model and delayed gene expression in the tumor spheroid compared to nonenveloped adenovirus. These results indicate that construction of artificial envelopes for nonenveloped viruses by lipid bilayer wrapping of the viral capsids constitutes a general strategy to rationally engineer viruses at the nanoscale with control over their biological properties.
我们开发了一种新颖、可重复且简便的方法，通过脂质分子在病毒衣壳周围自组装来构建腺病毒（Ad）的人工脂质包膜。无需改变病毒基因组或病毒衣壳的共轭表面化学性质，因此可以消除与大多数表面修饰病毒生产和纯化相关的困难。不同的脂质双层组成产生了具有由所用脂质类型决定的物理化学和生物学特性的人工包膜腺病毒。人工包膜腺病毒的物理化学特性，如载体大小、聚集程度、稳定性和表面电荷，与其生物学（基因转移）功能相关。在单层细胞培养中，使用两性离子包膜可阻断与柯萨奇病毒和腺病毒受体（CAR）的结合，而使用阳离子包膜可增强与细胞膜的结合。两性离子和阳离子脂质双层对腺病毒的包膜导致细胞单层中基因表达几乎完全消除，这是由于病毒粒子内体逃逸受阻。另外，在生理条件下由处于流体相的脂质双层构建的人工腺病毒包膜导致载体在三维肿瘤球体细胞培养模型中增强渗透，并且与无包膜腺病毒相比，肿瘤球体中的基因表达延迟。这些结果表明，通过病毒衣壳的脂质双层包裹为无包膜病毒构建人工包膜构成了一种在纳米尺度上合理设计病毒并控制其生物学特性的通用策略。
