Uptake of biodegradable microspheres by guinea pig alveolar macrophages
Garcia-Contreras, L., Cooney, D. J., Kazantseva, M., & Hickey, A. J. (2003, June). Uptake of biodegradable microspheres by guinea pig alveolar macrophages. Presented at International Society for Aerosols in Medicine 14th International Congress, .
Rationale: To study uptake of biodegradable microspheres (MS) and effectiveness of delivery as preliminary evaluation of a novel pulmonary tuberculosis vaccine. Methods: PLGA MS containing 1% rhodamine were prepared by solvent evaporation. MS size was determined by laser diffraction and confirmed by SEM. MS alone (MSa), 10% and 20% lactose/MS blends (8 3 108, 11 3 108 and 5 3 108 particles, respectively) were insufflated to guinea pig (GP) lungs. GPs were sacrificed at 24h and alveolar
macrophages (AMs) obtained by bronchoalveolar lavage. The phagocytic index (PI, average number of MS/AM) and the percentage of AMs involved in phagocytosis were measured by confocal microscopy. 1000–6000 AMs per GP were counted. Results: Median MS size was 1.6mm with GSD 2.1mm. The proportion of AMs involved in phagocytosis was 5% for MS and 20% blend, and 3% for 10% blend. Most AMs contained 1–2 MS. The PI was
0.06 for MSa, 0.08 for 20% blend and 0.03 for 10% blend. Conclusion: Biodegradable MS may be delivered to GP AMs. The efficiency of delivery of these MS by insufflation needs further optimization in terms of peripheral deposition in the lung. Funding: NIH grant #HL55789