The biomedical sensor Cell-Fit-HD^4D, reveals individual tumor cell fate in response to microscopic ion deposition

Abstract

Here we present the biomedical sensor cell-fluorescent ion track hybrid detector4D (Cell-Fit-HD4D) to reveal individual tumor cell fate in response to microscopic ion deposition in ion beam therapy. The sensor enables long-term monitoring of single tumor cells after clinical ion beam irradiation in combination with single-cell dosimetry. Cell-Fit-HD4D is read out in-situ by conventional optical microscopy. Direct visualization of a clinical ion beam is hereby possible for the first time. The possibility to reveal fate of individual cells from a cell cohort demonstrates that our biomedical sensor clearly differs from conventional experiments that characterize cellular response after radiation on a population level. Cell-Fit-HD4D is therefore used to mimics the clinical situation of a defined tumor depth during tumor treatment by ion beam therapy. Our biomedical sensor is able to provide crucial input for current mechanistic approaches to biophysical modelling of the effect of ionizing radiation on biological matter. In the clinical context, obtaining multi-dimensional physical and biological information on individual tumor cells is an important step to further transform ion beam therapy into a highly precise discipline within oncology.

Carbon ion dosimetry on a fluorescent nuclear track detector using widefield microscopy

“…Irradiation setup was similar to the setup used in [15]. The irradiated FNTD was the physical compartment of the biomedical sensor Cell-Fit-HD 4D introduced in [12]: Briefly, the bottom of a conventional 6 well glass bottom dish (MatTek) was replaced by a disk-shaped FNTD (diameter: 19 mm, thickness: 100µm, Fig.1). The resulting irradiated FNTDs were then stored in the dark until further analysis.…”

“…Cells expressing genetically encoded DNA damage markers such as 53BP1 growing on an FNTD can then be imaged after irradiation to asses the relation of ion hits to DNA foci [10,11]. Furthermore live cell imaging approaches after ionizing radiation can be used to determine the individual cell fate [12]. The current standard for the dosimetric readout method for the Landauer Al2O3:C,Mg FNTD is confocal laser scanning microscopy (CLSM) [9,13].…”

“…The experimental procedure of Cell-FIT-HD requires cells to be plated on an FNTD which is irradiated at the Heidelberg Ionenstrahl Therapiezentrum (HIT), then within 5-10 minutes, transferred to the widefield microscope where an initial image for cell position and ion traversal cross-referencing is captured. Then the cells are observed for up to 4 days using a variety of imaging methods to analyse the individual cells response to heavy ion irradiation [12]. After the live cell imaging the FNTD is transferred to the LSM where the fluorescent colour centres caused by the traversing ions can be detected.…”

“…The three diagrams in the centre and the two corresponding micrographs depict the process of irradiation (Left), live cell imaging of cells (Centre) and trackspot imaging (including image registration, Right). Overview of workflow of Cell-FIT-HD was adapted from Manuscript bioarchive, representations of FNTD adapted from[12]. Scale bars represent 10 µm.…”

Carbon ion dosimetry on a fluorescent nuclear track detector using widefield microscopy

“…Cells expressing genetically encoded DNA damage markers such as 53BP1 growing on an FNTD can then be imaged after irradiation to assess the relation of ion hits to DNA foci [10,11]. Furthermore live cell imaging approaches after ionizing radiation can be used to determine the individual cell fate [12]. The current standard for the dosimetric readout method for the Landauer Al2O3:C,Mg FNTD is confocal laser scanning microscopy (LSM) [9,13].…”