Preparation and Evaluation of Novel Folate Isonitrile 99mTc Complexes as Potential Tumor Imaging Agents to Target Folate Receptors

Abstract

In order to seek novel technetium-99m folate receptor-targeting agents, two folate derivatives (CN5FA and CNPFA) were synthesized and radiolabeled to obtain [99mTc]Tc-CN5FA and [99mTc]Tc-CNPFA complexes, which exhibited high radiochemical purity (>95%) without purification, hydrophilicity, and good stability in vitro. The KB cell competitive binding experiments indicated that [99mTc]Tc-CN5FA and [99mTc]Tc-CNPFA had specificity to folate receptor. Biodistribution studies in KB tumor-bearing mice illustrated that [99mTc]Tc-CN5FA and [99mTc]Tc-CNPFA had specific tumor uptake. Compared with [99mTc]Tc-CN5FA, the tumor/muscle ratios of [99mTc]Tc-CNPFA were higher, resulting in a better SPECT/CT imaging background. According to the results, the two 99mTc complexes have potential as tumor imaging agents to target folate receptors.

Preparation and Evaluation of a Novel 99mTc-Labeled Niraparib Isonitrile Complex as a Potential PARP-1 Imaging Agent

“…Isocyanate (−NC) is a strong coordination group that can form a stable complex with 99m Tc. Due to the poor solubility of niraparib in nonpolar solvents, a polyethylene glycol (PEG) chain was introduced to link niraparib and isonitrile groups during molecular design to increase hydrophilicity. , In this study, we synthesized and evaluated a 99m Tc-labeled niraparib derivative (i.e., [ 99m Tc]­Tc-CNPN) to obtain an effective tumor imaging agent to detect PARP-1 expression in tumors.…”