Institution: | aFaculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki Noda, Chiba 278-8510, Japan bCenter for Drug Delivery Research, Tokyo University of Science, 2641 Yamazaki Noda, Chiba 278-8510, Japan |
Abstract: | A method for exact determination of phagocytic activity of alveolar macrophage (M ) cells toward synthetic microspheres (MS) by optical microscopy was developed. We examined the effectiveness of the treatment of M samples with trypsin, acid or xylene to remove the polystyrene latex microspheres (PSL MS) attached to M cell membranes during their phagocytosis by M cells. We found that centrifugation, which was employed to collect M samples after incubation with MS, affected significantly the efficiency of the various treatments. Of the three treatments, xylene treatment without centrifugation was the most effective to determine the phagocytic activity of M cells, as xylene dissolved the PSL MS on the cell surface almost completely. This treatment was also effective in the case of poly(lactic-co-glycolic acid) MS (PLGA MS), which have been commonly used as an efficient vehicle for drug delivery system. |