Three-dimensional microtissues as an in vitro model for personalized radiation therapy.

This paper describes the use of 3D microtissues as an intermediate model between the 2D cell culture and the animal model to assess radiation-induced cellular and DNA damage in the context of personalized radiation therapy. An agarose microwell array was used to generate 3D microtissues with controlled size and shape. The microtissues were exposed to X-ray radiation of various doses, and the radiation damage to cells was examined using a variety of techniques with different end points. Damage to cell membranes and reduction in metabolic activity were examined with the MTT assay and dye inclusion assay. DNA damage was tested with the micronucleus assay, γ-H2AX immunostaining, and HaloChip assay. 3D microtissues exposed to X-rays are smaller compared to unexposed ones in extended cultures, indicating that X-ray radiation can retard the growth of cells in 3D microtissues, where cells at the outer shells of microtissues can prevent further damage to those inside.