Tissue-Cultured Chondrocytes Survive After Irradiation in 1300 Gy Dose

Background/Objectives: Radiobiology has shown heterogeneity in the sensitivity of cells to ionizing radiation, depending on a variety of conditions. The presence of an extracellular matrix (ECM) appears to confer a radioprotective effect on cells and can influence the cellular microenvironment by modulating the availability of oxygen and nutrients, which can affect cellular metabolism and stress responses. A three-dimensional cell culture allows the synergistic effect on cell survival to be obtained based not only on the radioprotective properties of the extracellular matrix but also on the stress-resistant endogenous properties of the cell culture. The aim of this study was to investigate the survival of chondrocytes in a 3D cell culture during high-dose ionizing irradiation. Methods: The properties of nasal chondrocytes were evaluated using a pellet culture model in which the cells were surrounded by a de novo synthesized extracellular matrix. Tissue cultures were exposed by gamma radiation at doses of 10, 100, and 1300 Gy. Cell viability was assessed after 2 days of irradiation by live/dead staining using confocal scanning laser microscopy. Results: Tissue-cultured chondrocytes survive after gamma-irradiation of low (10 Gy), medium (100 Gy), and high (1300 Gy) dosages; however, after irradiation of 1300 Gy, the percentage of surviving cells was lower. The average percentages of viable cells were evaluated as 82%, 79%, and 63% in low-, medium-, and high-dose groups, respectively. Conclusions: Under determined conditions, human cells are able to survive at doses of ionizing radiation that are significantly higher than the current limits.