文献：

MAGfect: a novel liposome formulation for MRI labelling and visualization of Cells

文献链接：

https://pubs.rsc.org/en/content/articlelanding/2006/ob/b605394g

作者：

Morag Oliver 1, Ayesha Ahmad, Nazila Kamaly, Eric Perouzel, Annabelle Caussin, Michael Keller, Amy Herlihy, Jimmy Bell, Andrew D Miller, Michael R Jorgensen

相关产品：

磷脂-罗丹明B DSPE-RB DSPE-rhodamine B

原文摘要：

Cellular entry of imaging probes, such as contrast agents for magnetic resonance imaging (MRI), is a key requirement for many molecular imaging studies, particularly imaging intracellular events and cell tracking. Here, we describe the successful development and in vitro analysis of MAGfect, a novel liposome formulation containing a lipidic gadolinium contrast agent for MRI, Gd-DOTA-Chol , designed to enter and label cells. Liposome formulation and cell incubation time were optimised for maximum cellular uptake of the imaging probe in a variety of cell lines. MRI analysis of cells incubated with MAGfect showed them to be highly MRI active. This formulation was examined further for cytotoxicity, cell viability and mechanism of cell labelling. One of the key advantages of using MAGfect as a labelling vehicle arises from its potential for additional functions, such as concomitant drug or gene delivery and fluorescent labelling. The gadolinium liposome was found to be an effective vehicle for transport of plasmid DNA (pDNA) into cells and expression levels were comparable to the commercial transfection agent Trojene.

成像探针（如用于磁共振成像（MRI）的造影剂）的细胞进入是许多分子成像研究的关键要求，特别是对细胞内事件和细胞跟踪进行成像。MAGfect的成功开发和体外分析，MAGfect是一种新型脂质体制剂，含有用于MRI的碘化钆造影剂Gd-DOTA Chol，旨在进入和标记细胞。优化了脂质体制剂和细胞孵育时间，以使成像探针在各种细胞系中获得*大的细胞摄取。用MAGfect孵育的细胞的MRI分析显示它们具有高度MRI活性。进一步检查了该制剂的细胞活力和细胞标记机制。使用MAGfect作为标记载体的一个关键优势来自其额外功能的潜力，如伴随药物或基因递送和荧光标记。

阳离子脂质体很容易通过内吞作用或膜融合被细胞吸收。*初的附着是通过轻微带轻微负电荷的细胞表面和带正电荷的脂质体之间的静电相互作用介导的。理想的细胞标记脂质体必须能够促进这种相互作用，同时传递*大数量的钆到细胞。

基于N-cholesteryloxycarbonyl-3,7-diaza-1,9-diaminonane（CDAN）-二油酰磷脂酰乙醇胺（DOPE）或1,2-二油酰氧氧基-3-（三甲基氨基）丙烷（DOTAP）体系。脂质体含有20-60mol%阳离子脂质，10-50mol%Gd·DOTA·chol1和0.5mol%DSPE-罗丹明（作为摄取测定的荧光探针），被超声处理，直到它们的大小在100-150nm之间，滴定直到获得生理pH。然后使用荧光细胞摄取试验评估每种配方的细胞标记效率。简而言之，将不同剂量的脂质体与培养的细胞一起孵育4或8小时。培养后，细胞被彻底清洗和裂解。用氯仿-甲醇混合物从细胞裂解液中提取取入细胞的脂质。然后用荧光光谱分析有机提取物，以定量DSPE-RB的数量，从而进入细胞中脂质体和gd-脂质的数量。结果：表明CDAN-based阳离子脂质体比更有效的标记DOTAP脂质体。