3049 - Liposome-Encapsulated Drug Delivery Inhibits Ferroptosis and Alleviates Radiation Injury
Presenter(s)
Y. Gao, J. He, Y. Chen, and Z. Zeng; Zhongshan Hospital, Fudan University, Shanghai, Shanghai, China
Purpose/Objective(s): The oxidative damage induced by ionizing radiation is closely related to the regulation of iron death, but its mechanism remains to be further explored. Amifostine, as the first FDA-approved radiation protection agent, can protect normal tissues from the toxic and side effects of radiotherapy, but its active metabolites are unstable and need to be used in large doses, resulting in significant side effects. Therefore, it is particularly important to develop new radiation protection agents with low toxicity and high efficiency.
Materials/Methods: (1) Pegylated liposomes coated with Amifostine were synthesized, and the particle size and morphology of liposomes were observed by DLS, XRD, FTIR and transmission electron microscopy. (2) The cell viability of Amifostine liposomes with different concentrations on three cell lines was determined by MTT. (3) BEAS-2B cells were irradiated with 0/2/4/6Gy to detect the damage of BEAS-2B cells and mitochondrial damage. (4) Label Cy5.5 to Amifostine liposomes and observe the distribution in mice by imaging in vivo. (5) Group mice were irradiated and treated with drugs, body weight and behavioral scores were recorded, blood biochemical and histopathological injuries were detected, and Q-PCR, Western-Blot and RNA sequencing were performed.
Results: (1) Characterization: Amifostine liposomes are amorphous spherical nanoparticles, larger than small molecules of Amifostine, with uniform particle size. (2) Biocompatibility: Amifostine liposomes had no effect on the proliferative activity of the three cell lines at 0.2mg/mL concentration. In vivo imaging showed that it mainly distributed in the liver and kidney of mice, the highest content in the liver after 2 hours, the highest content in the kidney after 4 to 12 hours, and the decrease after 24 hours, indicating that it may be cleared by kidney metabolism, and the liver has no accumulation. (3) Radiation protection: MTT and clonal formation experiments showed that Amifostine liposomes could improve cell proliferation activity, reduce DNA damage and ROS levels. Weight changes and behavioral scores of mice showed that amifostine liposomes inhibited weight loss and behavioral abnormalities. Pathological and blood biochemical results also showed remission of tissue damage. (4) Mechanism: In vitro and in vivo experiments have shown that Amifostine liposomes can clear ROS and reduce DNA damage. RNA sequencing and immunohistochemistry showed that it was involved in oxidative stress and metabolic regulation, and regulated GPX4 expression. The morphology of mitochondria was observed by electron microscope. It was found that Amifostine liposomes could protect mitochondria from radiation damage.
Conclusion: A novel nanodrug in the form of liposome coated Amifostine has been developed to improve radiation protection and reduce Amifostine toxicity, which is closely related to iron death in regulatory cell death. This provides a new way to explore the development of radiation protection agents.