树状大分子修饰纳米金颗粒作为CT分子探针的可行性初步研究

目的 研究树状大分子修饰纳米金颗粒作为CT分子探针的可行性.方法 将第5代聚酰胺胺树状大分子修饰的纳米金颗粒(Au DENPs)配制成15种浓度(0.001～0.1 mol/L)的悬液为实验组,相同浓度的非离子型碘造影剂(Omnipaque)为对照组,离体CT扫描比较相同浓度Au DENPs与Omnipaque的CT值差异.根据离体实验结果将6种浓度(0.006～0.02 mol/L)的Au DENPs 10 μl注射至BALB/C小鼠背部皮下行microCT扫描,观察其显影效果.结果 (1)离体实验发现当浓度≤0.01mol/L时,Au DENPs的CT值略低于相同浓度的非离子碘造影剂;当浓度>O.02mol/L时,Au DENPs的CT值高于相同浓度的非离子碘造影剂.(2)动物体内显像实验证实,当浓度≥0.009 mol/L时,经mieroCT成像可以清晰的显示注入小鼠皮下软组织的Au DENPs,而浓度≤0.008 mol/L时,注入小鼠体内的Au DENPs未被检出.结论 Au DENPs具有比现有CT造影剂更优秀的固有显影特性,具备成为CT分子探针的首要条件.

Preliminary research on dendrimer-entrapped gold nanoparticles as a CT molecular probe

Objective To study the feasibility of dendrimer-entrapped gold nanoparticles (Au DENPs) as a CT molecular probe. Methods Fifteen concentrations (0.001 to 0.1 mol/L) of gold nanoparticles were entrapped by amine-terminated polyamidoamine dendrimers of generation 5 in experiment groups. Same concentrations of non-ionic iodine contrast agent (Omnipaque) were set as control groups. The CT value of each concentrations of contrast agents in two groups were detected and compared in vitro. Six concentrations (0.006 ～ 0.02 mol/L) of Au DENPs at a dose of 10 μl were injected into the subcutaneous soft tissue of BALB/C mice back according to the experiment in vitro, then the experiment mice were scanned by a micro CT system to evaluate the development effect. Results (1) The CT values of Au DENPs were lower than those of non-ionic iodine contrast agent, when the concentration was 0.01 mol/L or lower in vitro. However, when the concentration exceeded 0.02 mol/L, the CT values of Au DENPs were higher than those of non-ionic iodine contrast agent. (2) Au DENPs at a dose of 10 μl injected into the subcutaneous soft tissue of mice could be detected by microCT, when the concentration of these particles was not less than 0.009 mol/L in vivo. At concentrations less than 0.008 mol/L, Au DENPs were undetectable in vivo. Conclusions Au DENPs show better inherent character for imaging than existing CT contrast agents, which preliminarily qualifies its use as a CT molecular probe.