Anti-radiation damage effect of polyethylenimine as a toll-like receptor 5 targeted agonist

Hu, Zhiqiang; Xing, Yaling; Qian, Yuanyu; Chen, Xiaojuan; Tu, Jian; Ren, Lening; Wang, Kai; Chen, Zhongbin

The maximum non-toxic dose of PEI was first determined in vivo to be70 mg/kg. Without γ radiation, C57BL/6J mice received an intra-peritoneal injection of 70 mg/kg PEI causing no sign of stress or body weight loss, and zero mortality (data not shown). The potential in vivo effect of PEI against ionizing radiation damage was assessed in C57BL/6J mice at a single dose of 8-Gy 60 Co γ-ray total body irradiation (TBI). The animal survival rate and survival time over a period of 30 days are shown in Fig. 3A . No mice in the irradiation control (IR mock) survived beyond 17 days post-irradiation. The final survival rates of mice that received a low dose of PEI, a high dose of PEI or AMI (the radiation protection positive control), on Day 30 were 50%, 64% and 80%, respectively. Compared with the irradiation control (IR mock), both animal survival time and survival rate significantly improved in mice that received a low dose of PEI (P = 0.019), or high dose of PEI (P < 0.001). Compared with the radiation protection positive control (150 mg/kg of AMI, 8.8 ± 0.9), the animal survival rate was higher in mice that received a high dose of PEI (9.1 ± 1.8), but lower for the low dose PEI group (6.7 ± 2.2, P < 0.001).