Bioprintable and injectable TiO-loaded hydrogels for photothermal therapy of glioma

Photothermal treatment (PTT) of glioma often requires a large number of animal models to enter the clinical stage, but the individual differences in animal models make the experimental results poor reproducibility. 3D bioprinting in vitro tumors made from hydrogels can provide efficient and accurate research models without sacrificing animals and avoiding species diversity. In this study, bioprintable and injectable TiO-loaded hydrogels were reported, which could be used for studying TiO NSs photothermal treatment of glioma. Results from the MTT kit showed that after photothermal treatment with TiO NSs, the survival rate of tumor cells in the 2D model was reduced to 35 ± 3. Rheological tests showed that the TiO-loaded hydrogels had good printability and injectability. 14 consecutive days of in vitro culture confirmed the feasibility of constructing in vitro tumors using bioinks composed of TiO-loaded hydrogels. In addition, in the photothermal therapy experiment of 3D bioprinting tumor models, the effective killing of tumor cells by TiO NSs confirmed the possibility of combining 3D bioprinted tumor models with photothermal therapy. After injecting TiO-loaded hydrogel in vivo, TiO NSs could effectively kill tumor cells by raising the temperature to 55 °C under near-infrared light irradiation for a short time. Bioprintable and injectable TiO-loaded hydrogel models are good for studying photothermal treatment of glioma, and 3D bioprinting tumor models have promising applications in photothermal therapy research for glioma.