摘要
以聚乙烯亚胺(PEI)为添加剂,在聚乙二醇(PEG)中高温热解乙酰丙酮铁(Fe(acac)3)合成超顺磁性氧化铁纳米粒子(PEI/PEG-SPIONs),再与钙离子螯合剂EGTA分别通过物理混合法和EDC/sulfo-NHS化学法合成了对钙离子敏感的磁共振成像(MRI)造影剂EGTA-SPIONs/P(物理混合)和EGTA-SPIONs/C(化学法)。PEI/PEGSPIONs、EGTA-SPIONs/P和EGTA-SPIONs/C分散于HEPES缓冲液中的电泳粒度分别为27.6±3.2 nm、32.1±5.2 nm和36.1±4.8 nm;加入Ca2+后EGTA-SPIONs/P和EGTA-SPIONs/C的平均电泳粒度均趋于变大,呈双峰分布,再加入EDTA后,平均电泳粒度又都趋于减小。MRI测试结果表明,当Ca2+浓度从0.8 mmol/L增加到1.2mmol/L时,EGTA-SPIONs/P和EGTA-SPIONs/C样品的T2值分别增加了33%和33.5%;将0.8 mmol/L EDTA加入混合0.8 mmol/L Ca2+的EGTA-SPIONs/P和EGTA-SPIONs/C的分散液中,其T2值分别降低了14%和42%。EGTA-SPIONs/P及EGTA-SPIONs/C对Ca2+浓度的增加均有反映,但Ca2+@EGTA-SPIONs/P的EDTA逆转效果不如Ca2+@EGTA-SPIONs/C的明显,化学法合成的EGTA-SPIONs/C更适合作为钙离子敏感剂。
Superparamagnetic iron oxide nanoparticles were synthesized by the thermal decomposition of iron（III） acetylacetonate（Fe（acac）3） in the mixture of poly（ethylene glycol）（PEG） and polyethyleneimine（PEI）（PEI/PEG-SPIONs）.EGTA was conjugated onto PEI/PEG-SPIONs using physical mixing（EGTA-SPIONs/P） and EDC/sulfo-NHS methods（EGTA-SPIONs/C）.The hydrodynamic sizes of PEI/PEG-SPIONs,EGTA-SPIONs/P and EGTA-SPIONs/C dispersed in HEPES solution were 27.6 ± 3.2,32.1 ± 5.2,36.1 ± 4.8 nm,respectively,after Ca2 ＋added,the average hydrodynamic sizes of EGTA-SPIONs/C and EGTA-SPIONs/P were all increased and were in bimodal distributions.After EDTA being further added,their average hydrodynamic sizes were all decreased.MRI measurements showed that,when Ca2 ＋concentration changed from 0.8 mmol/L to 1.2 mmol/L,the T2 values of EGTA-SPIONs/P and EGTA-SPIONs/C increased 33% and 33.5%,respectively.When 0.8 mmol/L EDTA was further added to the EGTA-SPIONs/C and EGTA-SPIONs/P solution at the presence of 0.8 mmol/L of Ca2 ＋,the T2 values decreased 14% and 42%,respectively.This work demonstrates that EGTA-SPIONs/C is better than EGTA-SPIONs/P as calcium-sensitive MRI contrast agents.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2016年第5期1335-1341,共7页
Journal of Synthetic Crystals
基金
国家自然科学基金(51562007)
