ABSTRACT
The development from single shot basic laser plasma interaction research toward experiments in which repetition rated laser-driven ion sources can be applied requires technological improvements. For example, in the case of radio-biological experiments, irradiation duration and reproducible controlled conditions are important for performing studies with a large number of samples. We present important technological advancements of recent years at the ATLAS 300 laser in Garching near Munich since our last radiation biology experiment. Improvements range from target positioning over proton transport and diagnostics to specimen handling. Exemplarily, we show the current capabilities by performing an application oriented experiment employing the zebrafish embryo model as a living vertebrate organism for laser-driven proton irradiation. The size, intensity, and energy of the laser-driven proton bunches resulted in evaluable partial body changes in the small (<1 mm) embryos, confirming the feasibility of the experimental system. The outcomes of this first study show both the appropriateness of the current capabilities and the required improvements of our laser-driven proton source for in vivo biological experiments, in particular the need for accurate, spatially resolved single bunch dosimetry and image guidance.
Subject(s)
Acceleration , Embryo, Nonmammalian/radiation effects , Lasers , Protons , Radiobiology/methods , Zebrafish/embryology , Animals , Feasibility StudiesABSTRACT
Translational research in radiation oncology is important for the detection of adverse radiation effects, cellular responses, and radiation modifications, and may help to improve the outcome of radiation therapy in patients with cancer. The present study aimed to optimize and validate a realtime labelfree assay for the dynamic monitoring of cellular responses to ionizing radiation. The xCELLigence system is an impedancebased platform that provides continuous information on alterations in cell size, shape, adhesion, proliferation, and survival. In the present study, various malignant human primary fibroblast cells (U251, GBM2, MCF7, A549, HT29) were exposed to 0, 5 and 10 Gy of Cobalt60 radiation. As well as the xCELLigence system, cell survival and proliferation was evaluated using the following conventional endpoint cellbased methods: Clonogenic, MTS, and lactate dehydrogenase assays, and apoptosis was detected by fluorescenceactivated cell sorting. The effects of ionizing radiation were detected for each cell line using impedance monitoring. The realtime data correlated with the colony forming assay results. At low cell densities (1,0002,000 cells/well) the impedancebased method was more accurate at monitoring dosedependent changes in the malignant human primary fibroblast cell lines, as compared with the endpoint assays. The results of the present study demonstrated that the xCELLigence system may be a reliable and rapid diagnostic method for the monitoring of dynamic cell behavior following radiation. In addition, the xCELLigence system may be used to investigate the cellular mechanisms underlying the radiation response, as well as the timedependent effects of radiation on cell proliferation and viability.