RT Journal Article SR Electronic T1 Interaction of Microspheres with Blood Constituents II: Uptake of Biodegradable Particles by Macrophages JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 114 OP 118 VO 40 IS 4 A1 Kanke, M. A1 Morlier, E. A1 Geissler, R. A1 Powell, D. A1 Kaplan, A. A1 Deluca, P. P. YR 1986 UL http://journal.pda.org/content/40/4/114.abstract AB The interaction of a poly(glycolic acid) biodegradable matrix with macrophages was studied in cell cultures using transmission and scanning electron microscopy as well as light microscopy. Phagocytosis was observed after as little as 10-min incubation time and as incubation time increased, the number of particles discernible within the cells also increased. The particles were identified in the cytoplasm enclosed within the lysosomal membrane. Cell death was evident after 48-hr incubation, following coalescence of macrophages in both the control and the test cells. Tissue distribution was evaluated for the biodegradable particles following intravenous injection. Localization was predominantly in the liver and spleen with some particle aggregates discernible within pulmonary capillaries 24 hr after injection. By 6 hr, particles were found within lysosomes in the cytoplasm of both monocytes and Kupffer cells in the liver. By 1 week some evidence of particle degradation was observed in lysosomes of Kupffer cells, while residual particles were no longer discernible after 2 weeks.