Novel 99mTc labeled complexes with bisphosphonate isocyanide: Radiosynthesis and evaluation as potential bone-seeking agents

In order to develop Tc-99m-labeled complexes with bisphosphonate isocyanide as novel bone imaging agents, two bisphosphonate isocyanide derivatives (CNALN and CNPAM) were synthesized and radiolabeling was performed for preparing the corresponding [Tc-99m]Tc(I) complexes. [Tc-99m]Tc-CNALN and [Tc-99m]Tc-CNPAM were obtained with high radiochemical purity and showed good in vitro stability. Both of them were hydrophilic and had high affinity to hydroxyapatite. The biodistribution studies in mice revealed [Tc-99m]Tc-CNALN showed higher bone/background ratios at 60 min post-injection. In single photon emission computed tomography (SPECT) imaging study, [Tc-99m]Tc-CNALN had an obvious accumulation in bone, suggesting it would be a promising bone-seeking agent.

Automated summary

Novel bone imaging agents were developed by synthesizing bisphosphonate isocyanide derivatives and radiolabeling them with Tc-99m. The [Tc-99m] Tc-CNALN complex showed high stability and bone/background ratio, making it a promising bone-seeking agent.