MRI活体示踪PEG/PEI-SPIO标记脂肪源性干细胞移植治疗AD大鼠模型

目的 观察采用聚乙二醇/聚乙烯亚胺修饰超顺磁性氧化铁（PEG/PEI-SPIO）MRI活体示踪脂肪源性干细胞（ADSC）移植治疗阿尔茨海默病（AD）的可行性。方法 将48只AD模型大鼠随机均分为标记组、未标记组和磷酸缓冲盐溶液（PBS）组，分别向侧脑室内注入PEG/PEI-SPIO标记或未标记ADSC及PBS液；另取16只大鼠作为假手术组。分别于第7、14、21、28天行头部MRI，检测海马、颞顶叶皮质、小脑T2值及脑组织铁含量。结果 移植后各时间点标记组海马区及皮质区T2值均较其余3组缩短（P均<0.05）；第7、14天其皮质区T2值小于海马及小脑，第21、28天海马区T2值小于皮质及小脑（P均<0.05）。相同时间点标记组各脑区铁含量均较其余3组增加（P均<0.05）；移植第7、14天，标记组颞顶叶皮质区铁含量较海马及小脑增加（P均<0.05），第21、28天海马区铁含量较颞顶叶皮质及小脑增加（P均<0.05）。结论 PEG/PEI-SPIO标记ADSC可反映其在AD模型鼠脑内的分布及迁移，并可通过MRI进行活体示踪。

In vivo MRI tracking after transplantation of PEG/PEI-SPIO labeled adipose derived stem cells in AD rats models

Objective To explore the feasibility of tracking the transplantation of adipose derived stem cells (ADSC) for Alzheimer disease (AD) with polyethylene glycol/polyethyleneimine modified superparamagnetic iron oxide (PEG/PEI-SPIO) with in vivo MRI. Methods Totally 48 AD rat models were randomly divided into labeled group, unlabeled group and phosphate buffer saline (PBS) group (each n=16). PEG/PEI-SPIO labeled or unlabeled ADSC and PBS were injected into the ventricle of rats, respectively. Other 16 rats were taken as the sham operation group. On the 7th, 14th, 21st and 28th day after transplantation, T2 value of temporal parietal cortex, hippocampus and cerebellum were measured with cranial MRI, and the iron content of brain tissue were measured on the above-mentioned brain areas. Results T2 values of the hippocampus and the cortex were shorter in labeled group than in other groups after transplantation (all P<0.05), and of the cortex were shorter than of the hippocampus and cerebella on the 7th and 14th day, of the hippocampus were shorter than of cortex and cerebella on the 21st and 28th day in the labeled group (all P<0.05). At the same time point, the iron content of the labeled group was higher than that of the other groups in each brain region (all P<0.05). The iron content of the cortex was higher than of other regions in the labeled group on the 7th and 14th day (all P<0.05), and the iron content of the hippocampus was higher than of other regions in the labeled group on the 21st and 28th day (all P<0.05). Conclusion Being labeled with PEG/PEI-SPIO, the distribution and migration of ADSC in the brain of rat AD models could be tracked with in vivo MRI.