这项研究旨在首次证明用皮秒级电子束单次爆发提供的戈伊级剂量照射生物细胞的可能性，从而产生前所未有的 1010 - 1011 Gy/s 的剂量率。癌症干细胞和人类皮肤成纤维细胞受到激光驱动源的 MeV 级电子束照射。每个脉冲的剂量高达 3 Gy，具有高空间均匀性（方差系数 3-6%），时间尺度在 10 - 20 ps 范围内。在照射过程中对剂量进行了表征，发现与蒙特卡罗模拟一致。使用克隆形成测定和 53BP1 病灶形成研究了两种细胞系的细胞存活和 DNA 双链断裂修复动力学，并将结果与​​剂量率为 的参考 X 射线进行了比较0.49 Gy/min。高达 3 Gy 的两种细胞系的克隆形成测定结果均符合线性二次模型，其中人体皮肤的 α=(0.68±0.08) Gy-1 和 β=(0.01±0.01) Gy-2对于成纤维细胞，对于癌症干细胞，α=（0.51±0.14）Gy-1和β=（0.01±0.01）Gy-2。与 0.49 Gy/min 的照射相比，我们的实验结果表明，尽管观察到 α 参数显着增加，但高达 3 Gy 的剂量的细胞存活率没有统计学上的显着差异，这可能暗示更复杂的损伤。焦点测量显示 1011 Gy/s 和 0.49 Gy/min 的照射之间没有显着差异。这项研究证明了使用皮秒级激光产生的电子束和 1010-1011 Gy/s 超高剂量率进行放射生物学研究的可能性。初步结果表明，在统计不确定性范围内，α 参数显着增加，可能表明更高密度的电离轨道会引起更复杂的损伤。版权所有 © 2023。由 Elsevier Inc. 出版。

This study aims to demonstrate, for the first time, the possibility of irradiating biological cells with Gy-scale doses delivered over single bursts of picosecond-scale electron beams, resulting in unprecedented dose rates of 1010 - 1011 Gy/s.Cancer stem cells and human skin fibroblasts were irradiated with MeV-scale electron beams from a laser-driven source. Doses up to 3 Gy per pulse with a high spatial uniformity (coefficient of variance 3-6%) and in a timescale in the range of 10 - 20 ps were delivered. The dose was characterised during irradiation and found in agreement with Monte Carlo simulations Cell survival and DNA double strand break repair dynamics were studied for both cell lines using clonogenic assay and 53BP1 foci formation and results were compared with reference x-rays at a dose rate of 0.49 Gy/min.Results from clonogenic assays of both cell lines up to 3 Gy are well fitted by a linear quadratic model with α = (0.68±0.08) Gy-1 and β = (0.01±0.01) Gy-2 for human skin fibroblasts and α = (0.51 ± 0.14) Gy-1 and β = (0.01 ± 0.01) Gy-2 for cancer stem cells. Compared to irradiation at 0.49 Gy/min, our experimental results indicate no statistically significant difference in cell survival rate for doses up to 3 Gy, even though a significant increase in the α parameter is observed, possibly hinting at more complex damages. Foci measurements show no significant difference between irradiations at 1011 Gy/s and 0.49 Gy/min.This study demonstrates the possibility of performing radiobiological studies with picosecond-scale laser-generated electron beams and ultra-high dose rates of 1010-1011 Gy/s. Preliminary results indicate, within statistical uncertainties, a significant increase of the α parameter, possible indication of the occurrence of more complex damage induced by a higher density of ionising tracks.Copyright © 2023. Published by Elsevier Inc.