INFLUENCE OF TECHNETIUM-99M-LABELING CONDITIONS ON PHYSICOCHEMICAL AND RELATED BIOLOGICAL PROPERTIES OF AN ACYLATED POLY-GALACTOSIDIC MACROPHAGE TARGETING AGENT FOR INFLAMMATION IMAGING

The potential of (99m)-Tc-J001 for the investigation of inflammatory l esions via the targeting of recruited macrophages (M phi) has already been documented in several experimental models and in human diseases. To achieve a functional imaging of inflammation via M phi targeting, m inimal labeled colloid content and high in vivo stability of Tc-99m-J0 01 are essential. The actual specificity of such scintigraphy is close ly dependent upon the radiolabeling of only the J001 molecules availab le for M phi targeting. To develop an appropriate radiopharmaceutical kit, optimization of the labeling conditions was achieved from a serie s of pilot formulations that were evaluated for radiolabeling efficien cy and both in vitro and in vivo Tc-99m-J001 stability. Colloids were characterized using autocorrelation spectroscopy and multiangle laser light scattering, radioactive colloid content of the formulations bein g deduced from biodistribution studies. This work has made possible th e definition of a formulation exhibiting a radiolabeling yield >97.0%, associated with in vivo stability and minimal colloid formation, thus greatly enhancing the specificity of such macrophage scintigraphy. Co pyright (C) 1996 Elsevier Science Inc.