Phagocytosis of Bioactive Microspheres

Abstract

The influence of several proteins on the uptake of microspheres was investigated using mouse peritoneal macrophages. Thioglycollate-stimulated macrophages were cultivated for 3 h with protein-grafted and protein-coated cellulose microspheres smaller than 2 μm in the presence and the absence of serum. Bovine serum albumin reduced the phagocytosis of microspheres, while y-globulin, human fibronectin, bovine tuftsin, and gelatin enhanced the phagocytosis. This trend was not influenced substantially by the presence of serum and the mode of surface binding of the proteins; that is, covalent grafting or physical adsorption (coating). However, in the case of gelatin binding, phagocytosis was greatly enhanced by the presence of serum as compared with the other proteins.