Abstract:
Objective To study the possibility of rhenium-188(
188Re)-labeled morpholino oligonucleotide as a therapeutic drug.
Methods Mercaptoacetyltriglycine(MAG
3) was used as a bifunctional chelater to test the effect of
188Re-labelled morpholino oligonucleotide on labeling rate.Biological activity,in vitro stability and distribution of
188Re-labeled morpholino oligonucleotide in normal mice were detected.
Results The labeling rate of
188Re-labeled morpholino oligonucleotide was 65%±12% with a radiochemical purity of over 93% and a specific activity of(2.37±0.32)MBq/μg.Re-oxidation of markers occurred in vitro,which caused disassociation of
188Re-labeled morpholino oligonucleotide.Addition of anti-oxidant and ascorbic acid into
188Re-labeled morpholino oligonucleotide could significantly improve its in vitro stability.
188Re-labelled morpholino oligonucleotide was mainly excreted through the kidneys.Its uptake was significantly higher in thyroid and stomach.
Conclusion MAG
3 can label
188Re-labeled morpholino oligonucleotide with a poor in vitro stability.Addition of anti-oxidant into
188Re-labeled morpholino oligonucleotide can improve its in vitro stability,but the markers will disassociate in vivo.Thus,
188Re-labeled morpholino oligonucleotide cannot be used as a therapeutic drug.