Molecular Immunology Unit, UCL Institute of Child Health, London, UK.
Biomaterials. 2012 Oct;33(29):7241-50. doi: 10.1016/j.biomaterials.2012.06.042. Epub 2012 Jul 17.
The efficient targeted delivery of nucleic acids in vivo provides some of the greatest challenges to the development of genetic therapies. We aim to develop nanocomplex formulations that achieve targeted transfection of neuroblastoma tumours that can be monitored simultaneously by MRI. Here, we have compared nanocomplexes comprising self-assembling mixtures of liposomes, plasmid DNA and one of three different peptide ligands derived from ApoE, neurotensin and tetanus toxin for targeted transfection in vitro and in vivo. Neurotensin-targeted nanocomplexes produced the highest levels of transfection and showed a 4.7-fold increase in transfected luciferase expression over non-targeted nanocomplexes in Neuro-2A cells. Transfection of subcutaneous Neuro-2A tumours in vivo with neurotensin-targeted nanocomplexes produced a 9.3-fold increase in gene expression over non-targeted controls. Confocal microscopy analysis elucidated the time course of DNA delivery with fluorescently labelled nanocomplex formulations in cells. It was confirmed that addition of a gadolinium lipid conjugate contrast agent allowed real time in vivo monitoring of nanocomplex localisation in tumours by MRI, which was maintained for at least 24 h. The peptide-targeted nanocomplexes developed here allow for the specific enhancement of targeted gene therapy both in vitro and in vivo, whilst allowing real time monitoring of delivery with MRI.
体内核酸的高效靶向递送为基因治疗的发展带来了一些最大的挑战。我们旨在开发纳米复合物制剂，以实现神经母细胞瘤肿瘤的靶向转染，同时可以通过 MRI 进行监测。在这里，我们比较了由脂质体、质粒 DNA 和三种不同的肽配体（来自 ApoE、神经降压素和破伤风毒素）组成的自组装混合物的纳米复合物，用于体外和体内的靶向转染。神经降压素靶向纳米复合物在 Neuro-2A 细胞中转染效率最高，与非靶向纳米复合物相比，转染的荧光素酶表达水平提高了 4.7 倍。用神经降压素靶向纳米复合物对皮下 Neuro-2A 肿瘤进行体内转染，基因表达水平比非靶向对照组提高了 9.3 倍。共聚焦显微镜分析阐明了细胞内用荧光标记的纳米复合物制剂进行 DNA 递送的时间过程。证实了添加钆脂质缀合物造影剂允许通过 MRI 实时监测肿瘤中纳米复合物的定位，这种定位至少可以维持 24 小时。这里开发的肽靶向纳米复合物允许在体外和体内特异性增强靶向基因治疗，同时允许通过 MRI 进行实时递送监测。
