With the purpose of enhancing the efficacy of
microparticle-encapsulated therapeutic agents, in this study we evaluated
the phagocytic ability of rat peritoneal exudate cells and the
preferential location of poly(d,l-lactide-co-glycolic acid)
(PLGA) microparticles inside these cells. The microparticles used were
produced by a solvent evaporation method and were characterized by dynamic
light scattering (DLS), transmission electron microscopy (TEM), and
scanning electron microscopy (SEM). Size distribution analysis using DLS
and SEM showed that the particles were spherical, with diameters falling
between 0.5 and 1.5 μm. Results from cell adhesion by SEM assay,
indicated that the PLGA microparticles are not toxic to cells and do not
cause any distinct damage to them as confirmed by the MTT
(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay.
Among the large variety of cell populations found in the peritoneal
exudates (neutrophils, eosinophils, monocytes, and macrophages), TEM
showed that only the latter phagocytosed PLGA microparticles, in a
time-dependent manner. The results obtained indicate that the
microparticles studied show merits as possible carriers of drugs for
intracellular delivery.