心肌细胞靶向脂质体的制备及体外靶向性研究

目的制备心肌细胞靶向脂质体，并对其体外心肌细胞靶向性进行研究。方法选用与β₁-受体阻滞剂艾司洛尔结构类似的亲脂性化合物PAC修饰脂质体(PAC-L)；将荧光标记的普通脂质体(Plain-L)与PAC-L加入体外培养的心肌细胞中，在特定实验条件下共同培养一定时间后，用荧光分光光度计测定心肌细胞摄取荧光脂质体的量。结果PAC-L与心肌细胞有较强的亲和力，且心肌细胞对PAC-L的摄取显著高于非心肌细胞(P<0.001)；常氧条件下2 h心肌细胞对PAC-L的摄取较Plain-L高约2.9倍，而在缺氧条件下则高出5.2倍；心肌细胞对Plain-L的摄取约11%是以内吞方式摄取的，而对PAC-L则约有56%是以内吞方式进行的。结论本文制备的PAC-L具有较强的心肌细胞特异靶向性，有可能成为一种有效的缺血心肌靶向性药物载体。

Preparation of cardiomyocyte-targeting liposomes and their targeting ability in virto

Aim To prepare the cardiomyocyte-targeting liposomes and investigate their cardiomyocyte targetability in vitro. Methods Liposomes modified with compound PAC were prepared (PAC-L); The uptake of PAC-L by cardiomyocytes was studied by incubating fluorescence labeled liposomes with cardiomyocytes in vitro and measuring the association of liposomes by a fluorescence spectrophotometer. Results A high affinity of PAC-L to the cardiomyocytes was observed, the amount of cell uptake of ~PAC-L by cardiomyocytes was higher than that by nonmyocyte (P<0.001); The amount of cardiomyocyte uptake of PAC-L on the normoxia condition 2 h was 2.9-fold higher than that of plain-L, and the increase was 5.2-fold when hypoxia occured; The form of liposome uptake changed, the amount of cardiomyocyte uptake of Plain-L by internalization was only 11%, while that of PAC-L was 56%. Conclusion It is indicated that PAC-L was a potential drug carrier for targeting to ischemic myocardium.