Biological effects of (125)I-UdR chitosan nanoparticles on hepatoma cells

Objective To evaluate the internal irradiation biological effects of 125I-UdR chitosan nanoparticles in hepatoma cells. Methods The accumulation and distribution of 125I-UdR-CS-DLN in hepatoma cells HepG2 and human liver tissue cells HL-7702 were observed with a confocal microscopy. The internal irradiation biological effects were evaluated by MTT assay, flow cytometry and single cell gel electrophoresis. The apoptosis of in situ rabbit liver tumor treated with 125I-UdR-CS-DLN was assayed by TUNEL staining technique. Results After 30 min of nano-particle treatment, its accumulation in the cytoplasm of HepG2 cells was significantly greater than that in HL-7702 cells. When the concentrations of 125I-UdR-CS-DLN was higher than 37 kBq/ml, the cell viability of HepG2 was significantly lower than that of HL-7702 at 24 and 48 h post-treatment(t=-4.46-6.31, P<0.05), and the HepG2 cells were arrested at G1 phase and significantly impaired at G2/M phase. In addition, the degrees of DNA double-strand break of both cell lines irradiated by 125I-UdR-CS-DLN were significantly higher than those treated with 125I-UdR, and the DNA repair capacity of HepG2 cells was significantly lower than that of HL-7702 cells(OTM: t=2.94, P<0.05; TDNA%: t=10.64, P<0.01). TUNEL staining showed that cell apoptosis could be induced in the rabbit liver carcinoma by 125I-UdR-CS-DLN but not by 125I-UdR. Conclusions The amount of 125I-UdR-CS-DLN absorbed by hepatoma cells is significantly higher than that of 125I-UdR, which suggests that 125I-UdR-CS-DLN induces more stronger internal radiation biological effects of apoptosis and DNA damage on hepatoma cells. Key words: 125I-UdR-chitosan-nanoparticles; Liver cancer; Passive targeting