Molecular imaging and therapeutic efficacy of 188Re-(DXR)-liposome-BBN in AR42J pancreatic tumor-bearing mice

Liposomes are good candidates as drug carriers and have been widely investigated in drug delivery systems. In this study, a new combination of bimodal Re-188-(DXR)-liposome-BBN radiochemotherapeutics was designed and studied for treating solid pancreatic tumor by intravenous administration. The in vivo nuclear microSPECT/CT imaging of tumor targeting, prolonged survival time and therapeutic efficacy were evaluated in AR42J malignant pancreatic solid tumor-bearing nude mice. MicroSPECT/CT imaging of Re-188-liposome-BBN pointed to significant targeting in tumors at 24 h after intravenous injection (SUV=2.13 +/- 0.98). Co-injection of a blocking dose of cold BBN (4 mg/kg) inhibited the accumulation of Re-188-liposome-BBN in tumors (SUV=1.82 +/- 0.31). For therapeutic efficacy, inhibition of tumor growth in mice treated with Re-188-DXR-liposome-BBN was precisely controlled [mean growth inhibition rate (MGI) = 0.092] and had longer survival time [life-span (LS) = 86.96%] than those treated with anticancer drug Re-188-liposome-BBN (MGI = 0.130; LS = 75%), Lipo-Dox-BBN (MGI = 0.666; LS = 3.61%) and untreated control mice. An additive tumor regression effect was observed (CI 0.946) for co-delivery of Re-188-DXRliposome-BBN radiochemotherapeutics. These results point to the potential benefit of the Re-188-(DXR)-liposome-BBN radiochemotherapeutics for adjuvant cancer treatment with applications in oncology.