Synthesis and preliminary evaluation of a <sup>99m</sup>
Tc-labeled folate-PAMAM dendrimer for FR imaging
作者:Manli Song、Zhide Guo、Mengna Gao、Changrong Shi、Duo Xu、Linyi You、Xiaowei Wu、Xinhui Su、Rongqiang Zhuang、Weimin Pan、Ting Liu、Xianzhong Zhang
DOI:10.1111/cbdd.12899
日期:2017.5
Folate receptor is an ideal target for tumor‐specific diagnostic and therapeutic. The aim of this study was to synthesize 99mTc‐labeled folate‐polyamidoamine dendrimer modified with 2‐hydrazinonicotinic acid (99mTc‐HP3FA) for FR imaging. The 99mTc‐HP3FA conjugate was prepared using N‐tris‐(hydroxymethyl)‐methylglycine and trisodium triphenylphosphine‐3,3′,3″‐trisulfonate as coligands. Physicochemical properties, in vitro cell uptake study, and in vivo micro‐single‐photon emission computed tomography/CT imaging were performed. The radiolabeled 99mTc‐HP3FA conjugate was prepared with high radiolabeling yield, good stability, and water solubility (logP = −1.70 ± 0.21). In cell uptake study, the radiolabeled conjugate showed high uptakes in the FR‐abundant KB cells and could be blocked significantly by excess folic acid. The 7721 cells which served as control group substantially had no uptakes. The results of micro‐single‐photon emission computed tomography/CT imaging exhibited that high accumulation of activity was found in FR‐overexpressed KB tumor, and the tumor‐to‐muscle ratio was approximately 25.78, while, using free FA as inhibitor, the uptakes of 99mTc‐HP3FA in KB tumor and kidney were obviously inhibited. In summary, a new radiocompound was synthesized successfully with specific FR targeting ability. The feasibility of 99mTc‐HP3FA for early diagnosis of FR‐positive tumors with non‐invasive single‐photon emission computed tomography imaging was demonstrated and the possibility of imaging‐guided drug delivery based on multifunctional polyamidoamine will be studied in the future.