Moreira João N, Ishida Tatsuhiro, Gaspar Rogério, Allen Theresa M
Department of Pharmacology, University of Alberta, Edmonton, Canada.
Pharm Res. 2002 Mar;19(3):265-9. doi: 10.1023/a:1014434732752.
Simple methods for the large-scale manufacture of ligand-targeted liposomes will be needed if clinical trials are to proceed. We tested a recently developed technology for inserting peptide ligands into preformed Stealth liposomes. Antagonist G-targeted liposomes (PLG) were prepared and loaded with doxorubicin and their cellular association and cytotoxicity were evaluated using the human small cell lung cancer H69 cell line.
The hexapeptide antagonist G was covalently coupled via a thioether bond to the terminus of polyethylene glycol (PEG) in micelles formed from maleimide-derivatized poly(ethylene glycol) (Mr 2000) distearoylphosphatidylethanolamine followed by transfer into preformed liposomes during a one-step incubation. For cellular association, we used radiolabeled liposomes. Cytotoxicity was evaluated using the MTT in vitro proliferation assay.
The postinsertion approach to the formation of peptide-targeted liposomes led to the production of PLG bearing a maximum of approximately 0.3 microg antagonist G/micromol phospholipid. These liposomes had increased cellular association to H69 cells relative to nontargeted liposomes and, when loaded with doxorubicin, they resulted in similar levels of cytotoxicity to those obtained by conventional coupling techniques.
The postinsertion technique is a simple, effective means for the production of biologically active peptide-targeted liposomes.
如果要开展临床试验，就需要有大规模制备配体靶向脂质体的简便方法。我们测试了一种最近开发的将肽配体插入预制隐形脂质体的技术。制备了拮抗剂G靶向脂质体（PLG）并装载阿霉素，使用人小细胞肺癌H69细胞系评估其细胞结合能力和细胞毒性。
六肽拮抗剂G通过硫醚键共价偶联到由马来酰亚胺衍生化的聚乙二醇（分子量2000）二硬脂酰磷脂酰乙醇胺形成的胶束中聚乙二醇（PEG）的末端，然后在一步孵育过程中转移到预制脂质体中。对于细胞结合，我们使用放射性标记的脂质体。使用MTT体外增殖试验评估细胞毒性。
肽靶向脂质体形成的插入后方法导致产生的PLG最多含有约0.3微克拮抗剂G/微摩尔磷脂。相对于非靶向脂质体，这些脂质体与H69细胞的细胞结合增加，并且当装载阿霉素时，它们产生的细胞毒性水平与通过传统偶联技术获得的相似。
插入后技术是生产具有生物活性的肽靶向脂质体的一种简单、有效的方法。
