| 一Investigations of labeling insulin-like growth factor 1 analogue with 99TcmThe insulin-like growth factor 1 contributes to the development and progression of many tumours such as pancreatic cancer and rectal cancer.The insulin-like growth factor 1 analogue can combine with the insulin-like growth factor 1 receptor that overpressed on the surface of the cancer cells,and then can induce the cancer cells apoptosis.So the IGF-1A can be used in the control of tumor growth .Objective: To establish a useful and stable method for labeling insulin-like growth factor 1 analogue (IGF-1A) with 99Tcm and study on the radioreceptor imaging of IGF-1.Methods:﹙1﹚The directly labeling method was adopted to label IGF-1A. Several labeling conditions were tested. The volume of Tween80 was from 0 to 10μL; the labeling efficiency was determined from 5min to 6 h after labeling; the concentration of SnCl2.2H2O from 0.75g/L to 4g/L; the amount of IGF-1A from 20 to 100μg; the volume of 99Tcm perrhenate was from 10 to 200μL.﹙2﹚To make use of 99Tcm -IGF-1A to combine with human pancreatic cancer line 8988, different concentration of human pancreatic cancer cells line 8988 were tested to have special binding and none-special binding with the 99Tcm -IGF-1A. Being labelled With 99Tcm, IGF-1A was used to make experiment of radioreceptor imaging trial and study on the distributions of 99Tcm -IGF-1A in pancreatic carcinoma-bearing nude mice and normal nude mice. 25 normal nude Mice and 25 nude Mice bearing human pancreatic carcinoma xenograft were used when xenograft were as big as almost 2 cm3 after 8 Weeks of growing were used to study on the distributions of 99Tcm -IGF-1A on different time-points. 99Tcm -IGF-1A was injected into peritoneal cavity. 15min,30min,1h,2h, 4h, 6h,7h later,the pancreatic carcinoma-bearing nude mice were examined with SPECT to measure the radioactivity of tumor xenograft and the normal organs.Results:﹙1﹚The labeling efficiency of 99Tcm -IGF-1A could reach (94.43±0.75)% and the amount of radiocolloid was (3.47±0.71)%.①When degraded the amount of Tween80, the labeling efficiency of 99Tcm -IGF-1A would increase, when this reaction had none Tween80, the labeling efficiency of 99Tcm -IGF-1A would obviously decrease.②When keeping time of reaction was 15 min, the labeling efficiency of 99Tcm -IGF-1A would reach (91.93±2.89)%,and the labeling efficiency of 99Tcm -IGF-1A would not change with time extended.③The labeling efficiency of 99Tcm -IGF-1A was related with the amount of SnCl2.2H2O,when degraded the amount of SnCl2.2H2O, the labeling efficiency of 99Tcm -IGF-1A would decrease.when the amount of SnCl2.2H2O was 3 g/L, the labeling efficiency was(91.90±1.15)%.④The labeling efficiency was high when the amount of IGF-1A increased.The top labeling efficiency was (92.77±0.99)%.⑤When the volume of 99Tcm perrhenate was 50μL, the labeling efficiency of 99Tcm -IGF-1A was (93.43±0.55)%.﹙2﹚The special binding efficiency of this reaction was 19.65%,19.35%,19.26%,17.03%,14.72%. Radioreceptor imaging results showed that 15min later the imaging of xenograft pancreatic cancer became increasingly distinct with the nonspecific background fading after intraperitoneal injection of 99Tcm -IGF-1A into tumor-bearing nude mice.The radioactivity ratio of tumor to non-tumor tissue such as muscle and blood increased as time prolonged.Conclusion: 99Tcm -IGF-1A can specificly bind with human pancreatic cancer line 8988.Imaging of 99Tcm labeled IGF-1A in human pancreatic carcinoma xenografts showed that 99Tcm -IGF-1A perhaps has some value in tumor diagnosis. 二Investigations of Labeling a Monoclonal Antibody against human pancreatic cancer with Rhenium-188Objective: To establish a useful and stable method for labeling a monoclonal antibody (McAb) of human pancreatic cancer with Rhenium-188.Methods: The directly labeling method was adopted to label the monoclonal antibody 2F4-2 C9 with 188Re.Several labeling conditions were tested:①the concentration of SnCl2 from 12 g/L to 20 g/L;②the labeling efficiency was determined from 30min,1h,,2h,3h,5h,7h after labeling;③the volume of 188Re perrhenate was from 50μLto 250μL.Results: (1) The optimum labeling method of 188Re-2F4-2 C9 was :200μL 0.2mol/L acetate buffer (pH 6.0), 100μL 2F4-2 C9 (0.6g/L); 200μL stannous chloride (20g/L) dissolved in sodium gluconate, 100μL 188Re perrhenate, incubation 1h at room temperature, then mixed with the other,followed by gel filtration to remove free radiolabel.(2) The labeling efficiency of 188Re- 2F4-2 C9 was 66%～75%,after purification, radiochemical purity was 85%～88%.As to the labeling condition:①the concentration of SnCl2 was 20g/L , the labeling efficiency of 88Re-2F4-2 C9 was (70.70±1.76)%;②the labeling efficiency of 88Re-2F4-2C9 would increse as time extended,the top labeling efficiency was (71.57±0.91)% ;③when the volume of 188Re perrhenate was 100μL , the labeling efficiency of 88Re-2F4-2 C9 was (70.95±1.94)%.Conclusion: Using the directly labeling method and after purification,we can get higher radiochemical purity of 88Re-2F4-2 C9 . |
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