Preliminary Study on the ^99mTc(CO)3-PNP5 Complex

The objective of this study is to synthesize 99mTc(CO)3-PNP5 through ligand exchange reaction and to study its biological characters. Labelling conditions of 99mTc(CO)3-PNP5 were optimized and its labelling yield was over 90% determined by TLC. The results of partition coefficient, charge character and stability studies indicated that 99mTc(CO)3-PNP5 is a lipophilic cation with good stability. Biological properties of 99mTc(CO)3-PNP5 and 99mTc(CO)3-PNP5(T) were valued contrastively in mice. The results showed that 99mTc(CO)3-PNP5(T) had higher myocardial uptake, lower liver uptake, and better heart-to-liver ratio. This indicated that the biological properties of 99mTc(CO)3-PNP5 were improved obviously by adding Tween-80.