RESUMO
Objective To construct 131 I labeled anti?EGFR immunoliposome nanoparticle ( 131 I?Cetuaximab ( C225)?BSA?PCL) , and investigate its inhibitory effect on EGFR?overexpressing cancer cells in vitro. Methods Anti?EGFR liposome nanoparticle C225?BSA?PCL and non?targeted liposomes BSA?PCL were constructed. The products were observed with transmission electron microscopy and dynamic light scat?tering. The EGFR?targeted binding and cellular uptake in EGFR?overexpressing cancer cells were observed with flow cytometry and confocal microscopy. Anti?EGFR and non?targeted liposomes were labeled with 131 I using the chloramine?T method. The targeted cell killing effects of 131 I labeled liposomes were analyzed using MTT assay. The time?dependent cellular uptake analysis was used to evaluate the slow?release effects of the 131 I labeled liposomes. The independent?samples t test was used for data analysis. Results The EG?FR?targeted liposome C225?BSA?PCL and non?targeted liposome BSA?PCL were successfully constructed, and the effective diameters were approximately 130-180 nm. Flow cytometry and confocal microscopy re?vealed significant uptake of C225?BSA?PCL in EGFR?overexpressing tumor cells. BSA?PCL could also bind to cells with minimal and weak tumor retention. The EGFR?targeted radioactive liposome 131I?C225?BSA?PCL showed greater targeted cell killing effect than non?targeted liposome 131I?BSA?PCL,the IC50 values of 131I?C225?BSA?PCL and 131 I?BSA?PCL were 0. 03-1. 32 and 0. 25-12. 19, respectively. The uptakes of 131 I?C225?BSA?PCL was higher than that of 131 I?BSA?PCL ( t=3.03-16.86, all P<0.05) and reached the maxi?mal level at 4 h after incubation. Conclusions The EGFR?targeted liposome C225?BSA?PCL demonstrated superior cellular binding and uptake on EGFR?overexpressing cancer cells compared with BSA?PCL. The EGFR?targeted radioactive liposome 131 I?C225?BSA?PCL had favorable intracellular retention and excellent targeted cell killing effect, and could effectively suppress the growth of EGFR?overexpressing cancer cells.
RESUMO
A spectrophotometric method was developed for the determination of iron(III)-dimethyldithiocarbamate (ferbam) by concerting it into an iron(III)-9-(4-carboxyphenyl)-2,3,7-trihydroxyl-6-fluorone complex. In NH(3)-HAc buffer solution (pH 6.5), the reagent reacts with ferbam to form a blue complex with a maximum absorption peak at 640nm. The reaction can be completed rapidly at room temperature and the absorbance is stable for at least 24h. The apparent molar absorption coefficient, Sandell's sensitivity of the complex, the detection limit and the relative standard deviation were found to be 1.06x10(5)lmol(-1)cm(-1), 3.9ngcm(-2), 2.2ngml(-1) and 1.06%, respectively. From 0 to 75mug of ferbam in 25ml solution the absorbance obeyed Beer's law. The effect of foreign ions and other dithiocarbamates were also studied in detail. The results indicated that all coexisting ions examined can be tolerated in considerable amounts, especially other dithiocarbamates such as ziram and zineb, which always interfere with the determination of ferbam in the literature. The proposed method is very sensitive, selective and simple, it has been applied to determine ferbam in commercial samples.