Flow cytometric and optical microscopic evaluation of poly(D, L-lactide-co-glycolide) microspheres phagocytosis by pig alveolar macrophages.

摘要

The phagocytosis of fluorescent poly(D,L-lactide-co-glycolide) microspheres by fresh and frozen pig alveolar macrophages was investigated by optical microscopy on adherent cell culture and by flow cytometry with cell suspension. The kinetic of phagocytosis was studied on a 360 min period as a function of the ratio between microspheres and macrophages (MS:AM ratio from 1:1 to 10:1). No difference of phagocytosis between fresh and frozen macrophages was observed whatever the MS:AM ratio following flow cytometric evaluation while a significant phagocytosis pattern was noticed following optical microscopic evaluation for the highest ratio. The intensity of phagocytosis was dependent on the duration of incubation and dependent, but not proportionally, to the MS:AM ratio showing that the highest efficiency was obtained with the MS:AM ratio of 1:1. Flow cytometry analysis has shown a correlation between cell population and fluorescent events suggesting that phagocytosis of nonfluorescent antigen-loaded particles with different characteristics could be investigated.