Saatchi Katayoun, Häfeli Urs O
Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC V6T 1Z3, Canada.
Bioconjug Chem. 2009 Jun;20(6):1209-17. doi: 10.1021/bc900066j.
Poly(L-lactide) (PLA) microspheres tailored with a tridentate chelating group were radiolabeled with (99m)Tc(H(2)O)(3)(CO)(3) and optimized for labeling efficiency and stability. Various ligand-polymer blend compositions with commercial PLA (from 2% to 100%) were evaluated. Labeling efficiencies over 95% were achieved in a 5 min reaction using 100% of the ligand-polymer or within 15 min using a 5% ligand-polymer blend. The addition of 1.5% of PEGylated copolymer to the blend did not affect the labeling efficiency of these particles but changed their in vivo behavior. MicroSPECT/CT imaging showed significant uptake of non-PEGylated microspheres by the murine lung, while only the liver and spleen took up PEGylated microspheres. Such (99m)Tc radiolabeled biodegradable microspheres will be useful diagnostic imaging agents for visualization of the functioning reticuloendothelial system (RES). Similarly, other sizes of the same microspheres will allow imaging of lung perfusion, bone marrow, lymph and inflammation scintigraphy, and radioembolization therapy.
用三齿螯合基团修饰的聚（L-丙交酯）（PLA）微球用[（99m）Tc（H₂O）₃（CO）₃]⁺进行放射性标记，并对标记效率和稳定性进行了优化。评估了各种含商业PLA（2%至100%）的配体-聚合物共混物组成。使用100%的配体-聚合物在5分钟反应中或使用5%的配体-聚合物共混物在15分钟内实现了超过95%的标记效率。向共混物中添加1.5%的聚乙二醇化共聚物不会影响这些颗粒的标记效率，但会改变它们的体内行为。MicroSPECT/CT成像显示，未聚乙二醇化的微球在小鼠肺中有明显摄取，而聚乙二醇化的微球仅被肝脏和脾脏摄取。这种（99m）Tc放射性标记的可生物降解微球将成为用于可视化功能性网状内皮系统（RES）的有用诊断成像剂。同样，相同微球的其他尺寸将允许进行肺灌注成像、骨髓成像、淋巴和炎症闪烁显像以及放射性栓塞治疗。
