Jones B G, Dickinson P A, Gumbleton M, Kellaway I W
The Welsh School of Pharmacy, University of Wales, CF10 3XF, Cardiff, UK.
Int J Pharm. 2002 Apr 2;236(1-2):65-79. doi: 10.1016/s0378-5173(02)00016-9.
Respirable poly(lactic co-glycolic acid) (PLGA) microspheres (2-3 microm diameter), were fabricated as a model drug delivery system whose uptake by macrophages could be quantified by fluorescent activated cell sorting. The microspheres exhibited minimal release of the entrapped flourophore (rhodamine B) and thus avoided possible fluid phase uptake of the flourophore. Externally bound microspheres were removed from the cell membrane by acid washing. The fluorescent intensity associated with the cells arose, therefore, from the internalised microspheres. NR8383 continuous culture alveolar macrophages were verified against primary cultures as a good model of alveolar phagocytosis. Peritoneal macrophages were also isolated and systemic and alveolar phagocytosis compared. Poloxamer 338 adsorbed at the microsphere surface did not reduce phagocytosis by NR8383 macrophages. It did, however, reduce the number of microspheres contained in primary alveolar macrophages but did not reduce the percentage of phagocytic cells. Poloxamer coatings did not reduce phagocytosis by peritoneal macrophages once the ratio of five microspheres per cell was exceeded. Dipalmitoylphosphatidylcholine (DPPC), the major component of lung surfactant, was added to cultures to model the alveolar environment where it was observed to reduce phagocytosis. In light of this finding, microspheres were coated in DPPC, which reduced their uptake by all cell types at all microsphere to cell ratios.
可吸入的聚乳酸-羟基乙酸共聚物（PLGA）微球（直径2-3微米）被制备为一种模型药物递送系统，其被巨噬细胞摄取的情况可通过荧光激活细胞分选进行定量分析。这些微球对包裹的荧光团（罗丹明B）释放极少，从而避免了荧光团可能的液相摄取。通过酸洗从细胞膜上去除外部结合的微球。因此，与细胞相关的荧光强度来自内化的微球。NR8383连续培养肺泡巨噬细胞经原代培养验证是肺泡吞噬作用的良好模型。还分离了腹膜巨噬细胞，并比较了全身和肺泡吞噬作用。吸附在微球表面的泊洛沙姆338不会降低NR8383巨噬细胞的吞噬作用。然而，它确实减少了原代肺泡巨噬细胞中所含微球的数量，但没有降低吞噬细胞的百分比。一旦每个细胞的微球比例超过五个，泊洛沙姆涂层不会降低腹膜巨噬细胞的吞噬作用。肺表面活性剂的主要成分二棕榈酰磷脂酰胆碱（DPPC）被添加到培养物中以模拟肺泡环境，在该环境中观察到它会降低吞噬作用。鉴于这一发现，微球用DPPC包被，这在所有微球与细胞比例下都降低了所有细胞类型对它们的摄取。
