主动靶向脂质体的相变温度与靶细胞摄取的相关性研究

Correlation between Phase Transition Temperature and the Target-specific Cellular Uptake of Active Targeting Liposomes

分别采用二硬脂酰磷脂酰胆碱（DSPC）、氢化大豆磷脂（HSPC）、二棕榈酰磷脂酰胆碱（DPPC）和二肉豆蔻酰磷脂酰胆碱（DMPC）为载体,制备了NGR肽（Asn-Gly-Arg）修饰的主动靶向脂质体,并用其负载香豆素-6。结果表明,4种脂质体的粒径为120~160 nm,粒度分布均匀,ζ电位接近中性,包封率均在95%以上。差示扫描量热分析（DSC）表明,4种脂质体的相变温度（Tm）值由高至低分别为DSPC脂质体〉HSPC脂质体〉DPPC脂质体〉DMPC脂质体。以CD13高表达的HT1080细胞为模型,采用流式细胞仪、激光共聚焦显微镜观察评价脂质体的入胞效果。结果显示,脂质体的入胞效率与Tm值呈正相关。

Four kinds of active targeting liposomes loaded with coumarin-6 surface modified with NGR （Asn-Gly-Arg） were prepared with distearoyl phosphatidylcholine （DSPC）, hydrogenated soya phosphatide （HSPC）, dipalmitoyl phosphatidylcholine （DPPC） and dimyristoyl phosphatidyl choline （DMPC） as carrier, respectively. The results showed that the mean diameters of these four liposomes were in the range of 120 - 160 nm, and they all had a uniform size distribution and nearly neutral potential. Their encapsulation efficiencies were all above 95 %. According to the result of differential scanning calorimetry （DSC） analysis, the phase transition temperature （Tin） values of these liposomes were ranked in descending order as follows： DSPC liposomes, HSPC liposomes, DPPC liposomes and DMPC liposomes. With CD13 overexpressing cells HT1080 as the cell model, flow cytometry analysis and confocal laser microscopy were applied to evaluate the cellular uptake efficiency. The results showed that the cellular uptake efficiencies of the NGR-modified liposomes were positively correlated with their Tm values.