Structural Control for Tunable Hyperthermia-Induced Cellular Responses Using 3D-Printed Platforms.

Three-dimensional (3D) printing technologies have revolutionized bioengineering by enabling the fabrication of complex, customized structures with high morphological compatibility for specific functions. Most advances in the materials aspect of 3D printing have focused on developing inks that provide high stability and precise deposition for specific printing techniques. A new generation of printable materials not only ensures structural and mechanical integrity, but also incorporates additional functionalities directly into the material. The integration of rational structural design with functional materials offers powerful tools for biomedical applications. In this study, we developed a platform for investigating thermoresponsiveness in cell culture. By inducing controllable, localized heating, we examined the effects of hyperthermia on cancer cells, an emerging treatment modality gaining increasing attention as a promising anticancer strategy. We demonstrate that structurally controlled 3D-printed objects composed of polymer and iron oxide (IO) can generate defined thermal gradients upon exposure to infrared irradiation, thereby inducing differential cellular responses. Using precise spatial control with Digital Light Processing (DLP) printing, we created hyperthermia models. We demonstrated that the experimental conditions can detect changes in cell sensitivity, showing that pre-exposure of cancer cells to the cryoprotective compound trehalose alters their heat resistance. Moreover, repeated thermal cycles promoted the emergence of a cell subpopulation with enhanced heat resistance and increased aggressiveness, highlighting the platform's ability to drive adaptive cell selection based on thermal tolerance. Our findings indicate that thermal conditioning via 3D-printed platforms can serve as a robust tool for studying cellular responses to hyperthermia and may contribute to optimizing hyperthermia-based cancer therapies.