Laboratory of Pharmaceutical Technology, Dept. of Pharmacy, School of Health Sciences, University of Patras, Patras, Greece.
Nanomedicine. 2011 Oct;7(5):572-9. doi: 10.1016/j.nano.2011.06.010. Epub 2011 Jun 24.
The DRV technique (followed by extrusion) was used for construction of hydrophilic-USPIO encapsulating liposomes. Magnetoliposomes (ML) were characterized for size, surface charge, entrapment, physical stability and magnetic properties (relaxivity). Results show that nanosized extruded-DRV MLs encapsulate higher amounts of USPIOs in comparison with sonicated vesicles. Fe (III) encapsulation efficiency (EE) is 12%, the highest reported to date for nanosized MLs. EE of MLs is influenced by ML membrane composition and polyethyleneglycol (PEG) coating. PEG-coating increases ML EE and stability; however, r(2)-to-r(1) ratios decrease (in comparison with non-PEGylated MLs). Most ML-types are efficient T2 contrast agents (because r(2)-to-r(1) ratios are higher than that of free USPIOs). Targeted MLs were formed by successfully immobilizing OX-26 monoclonal antibody on ML surface (biotin-streptavidin ligation), without significant loss of USPIOs. Targeted MLs retained their nanosize and integrity during storage for 1 month at 4 °C and up to 2 weeks at 37 °C.
DRV 技术（随后进行挤压）用于构建亲水性-USPIO 包封脂质体。对磁脂质体（ML）进行了大小、表面电荷、包封率、物理稳定性和磁性能（弛豫率）的表征。结果表明，与超声处理的囊泡相比，纳米挤压 DRV ML 包封了更多的 USPIO。Fe(III)包封效率（EE）为 12%，是迄今为止报道的纳米 ML 中最高的。ML 的 EE 受 ML 膜组成和聚乙二醇（PEG）涂层的影响。PEG 涂层增加了 ML 的 EE 和稳定性；然而，r(2)-to-r(1) 比值降低（与非 PEG 化 ML 相比）。大多数 ML 类型都是有效的 T2 对比剂（因为 r(2)-to-r(1) 比值高于游离 USPIO）。通过成功地将 OX-26 单克隆抗体固定在 ML 表面上（生物素-链霉亲和素连接），形成了靶向 ML，而没有明显损失 USPIO。在 4°C 下储存 1 个月和在 37°C 下储存长达 2 周期间，靶向 ML 保持其纳米尺寸和完整性。
