Preparation and biological evaluation of 99mTc-TMPP as a novel agent for tumor diagnosis

Abstract

Compound 5, 10, 15, 20 tetrakis {4-methoxyphenyl} 21H, 23H porphyrin (TMPP) was labeled with technetium-99m via direct labeling technique using stannous chloride as a reducing agent. The optimum conditions that gave high labeling yield (95.2%) of 99m Tc-TMPP complex were achieved by using 3mg TMPP, 100µg SnCl 2 .2H 2 O, at pH 3 and 30min reaction time. Molecular geometry was used to illustrate the structure of complex which is formed between 99m Tc and TMPP. The preclinical evaluation and biodistribution in solid tumor bearing mice showed high biological accumulation in solid tumor cells (22.66 % injected activity/ g tissue) and high T/NT ratio equal to 3.21 ± 0.15 at 30 minutes post-injection. Data described before could recommend 99m Tc-TMPP as a potential targeting radiopharmaceutical for tumor imaging.