ABSTRACT
Objective To evaluate the therapeutic effects of poly(N-isopropylacrylamide)adriamycin magnetic nanoparticles(ADM-PNIPAM-Fe_3O_4)on liver VX2 tumor in rabbits via transcatheter arterial chemoembolization.Methods VX2 tumor pieces were successfully implanted into liver lobes of rabbits with liver tumors formation.All the animals were randomly divided into 4 groups of 8 each.Group A(control group)injected with 10 ml physiologic saline,Group B(ADM group)treated with free adriamycin (1 mg/kg)via arterial infusion,Group C(ADM-PNIPAM group)ADM-PNIPAM(1.5 mg/kg)was infused through arterial route,Group D(ADM-PNIPAM-Fe_3O_4+M group)ADM-PNIPAM-Fe_3O_4(2 mg/kg)was infused through arterial route;all were in individual doses,respectively;meanwhile an persistant magnet with intensity of 0.4 T was stabilized at the tumor region.Spiral CT scans were performed to measure size of liver tumors and evaluate lung metastasis at 1 day before operation and 14 days after operation.All experimental animals were sacrficed on the 15th days after operation and followed by pathologic and histologic examination of the tumor and lung specimens including changes befor and after the operation with correlative comparisons.Results There were no significant difference in volumes of tumors among 4 groups at 1 day before operation.The average tumor volume in the group A was(23.87?7.02)cm~3 at 14 days after operation;(7.70?1.53)cm3 in group B;(4.29?0.25)cm~3 in group C;(2.05?0.18)cm~3 in group D. The average tumor volumes in the group B,group C and group D were significantly smaller than that in the control group A at same time after operation and there was significant difference among the three experimental groups.According to the order of tumor sizes from small to large was as follows:group D＜group C＜group B＜group A.It showed that the average size of group D(ADM-PNIPAM-Fe_3O_4+M group) was the smallest among the 4 groups.Lung metastatic rates were 100%,66.7%,37.5% and 12.5% in group A,group B,group C and group D at 14 days after operation,respectively.Lung metastatic rates of group D was lower than that of group A,but there were no significant differences among group A,B and C.But pathological examination showed that there were lesser number of lung metastatic tumors in group B and C than that of group A .The intratumoral necrotic degrees showed as group D＞group C＞group B＞group A. Conclusions ADM-PNIPAM-Fe_3O_4 treatment for liver tumor via vascular interventional method combined with magnetic field localized in the lesion possesses significant inhibitory effect on tumor growth of liver VX2 tumor in rabbits.ADM-PNIPAM-Fe_3O_4 is thus initially confirmed as a kind of effective praeputium in interventional chemoembolization.