Maha S. Al Mutairi, Mohammed A. Motaleb, Nadia G. Haress and Wafaa A. Zaghary
Estrogens participate in several biological processes through different molecular mechanisms. Their final actions consist of a combination of both direct and indirect effects on different organ and tissues. Estrogen may have pro- and anti- inflammatory properties depending on the situation and the involved tissue. 2-aminoestrone-3-methyl ether as an estrogenic derivative was prepared with a yield of 55% and well characterized. 99mTc-2-aminoestrone-3-methyl ether radiotracer was synthesized to study its inflammatory binding specificity as a novel selective radiopharmaceutical for inflammation imaging. Effect of 2-aminoestrone-3-methyl ether concentration, stannous chloride dihydrate (SnCl 2 .2H 2 O) concentration, pH and reaction time on the percent labeling yield of 99mTc-2-aminoestrone-3-methyl ether complex was studied in details. 99mTc- 2-aminoestrone-3-methyl ether complex was obtained at a maximum yield of 98.6% by mixing 60 mg of 2-aminoestrone-3- methyl ether with 1mg SnCl 2 .2H 2 O at pH 1 and 30 min reaction time. Biodistribution study of 99mTc-2-amino estrone-3- methyl ether complex in both bacterial infection and sterile inflammation showed high and rapid accumulation of 99mTc-2- aminoestrone-3-methyl ether complex at the site of sterile inflammation compared to bacterial infection sits [(target-to-non target, T/NT) ratio equal to 4.12▒0.02]. High biological accumulation in inflamed cells suggests that 99mTc-2-aminoestrone- 3-methyl ether complex may be suitable as a potential selective radiotracer able to image inflammatory sites.