Hwang K J, Padki M M, Chow D D, Essien H E, Lai J Y, Beaumier P L
Biochim Biophys Acta. 1987 Jul 10;901(1):88-96. doi: 10.1016/0005-2736(87)90259-8.
The distribution of liposomes within the intravascular space and the extent to which they escape into extravascular space strongly impact on the application of lipid vesicles as a carrier for pharmacologically active agents. The present study investigates how intact small unilamellar vesicles (SUV) may be taken up by different tissues after intravenous injection into mice, using various types of SUV with different entrapped markers, lipid composition, size, doses of liposomal lipids and stability in the blood. Our focus was specifically on sphingomyelin (or distearoyl phosphatidylcholine)/cholesterol (2:1, mol/mol) SUV, which are known to be stable in the blood circulation. Our results indicated that, in addition to the reticuloendothelial tissues, intact SUV were taken up in several other parts of the body, including intestine, skin, carcass and legs. It appears that the accumulation of SUV in the intestine and the skin increases with time post-injection. Furthermore, from the kinetic data, the process of uptake of SUV by the skin and intestine is compatible with a non-saturable pathway, which follows first-order kinetics. This suggests that the cells involved in the uptake of SUV in the intestine and skin are not phagocytic cells, which are normally saturable.
脂质体在血管内空间的分布以及它们逸出到血管外空间的程度，对脂质囊泡作为药理活性剂载体的应用有很大影响。本研究调查了完整的小单层囊泡（SUV）在静脉注射到小鼠体内后如何被不同组织摄取，使用了具有不同包封标记物、脂质组成、大小、脂质体脂质剂量和血液稳定性的各种类型的SUV。我们特别关注鞘磷脂（或二硬脂酰磷脂酰胆碱）/胆固醇（2:1，摩尔/摩尔）的SUV，已知它们在血液循环中是稳定的。我们的结果表明，除了网状内皮组织外，完整的SUV还被身体的其他几个部位摄取，包括肠道、皮肤、胴体和腿部。似乎SUV在肠道和皮肤中的积累随着注射后的时间增加。此外，从动力学数据来看，皮肤和肠道摄取SUV的过程与非饱和途径相符，遵循一级动力学。这表明参与肠道和皮肤摄取SUV的细胞不是通常可饱和的吞噬细胞。
