ABSTRACT
Objective To study the potential and value of ultrasmall superparamagnetic iron oxide (USPIO) conjugated by mesothelin antibody as MRI targeting contrast agent for diagnosis of implanted human pancreatic carcinomas in nude mouse.Methods Nude mouse tumor models bearing multiple human pancreatic carcinomas at different time points was established and they were randomized into two groups,and USPIO or MSLN-USPIO were used as contrast enhanced agents in the 3.0T MRI scan,respectively,then the positive detection rates for smallest tumors,and the signal intensity of tumors in T2 mapping images of both unenhanced and contrast enhanced scanning and the negative enhancement rate were measured,then Prussian blue staining was performed in alI the tumor specimens to observe the difference of Fe3 + ion deposition.Results There was no statistical significance between USPIO group and MSLN-USPIO group in the positive detection rates for smallest tumors.In USPIO group,the negative enhancement rate of left or right axilla tumors was (12.29 ±7.45)％ and (11.06 ±5.91)％,and they were (33.88 ±6.09)％ and (43.29 ± 11.64)％ in MSLN-USPIO group.There was statistical significance in the difference of signal intensity between unenhanced and contrast enhanced in left or right axilla tumors (P ＜ 0.05),and the negative enhancement rate in MSLN-USPIO group was significantly higher than that in USPIO group (P ＜0.05).The Fe3+ ion deposition in tumors' tissue in MSLN-USPIO group was significantly more than that in USPIO group.Conclusions The enhanced effect of MSLN-USPIO is superior to USOPIO,and it can be a tumor targeted MR contrast enhanced agent for the diagnosis of pancreatic carcinoma in nude mouse.