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.
Hao Xu,Songsong Li,Lei Ge,Changcun Han,Yangqin Gao,Dongsheng Dai
Efficient separation of photo-generated electrons and holes is a crucial aspect for photocatalytic hydrogen evolution . Herein, novel plate-like Co(OH) 2 decorated TiO 2 nanosheets for photocatalytic water splitting were synthesized by a facile in-situ synthetic method. The results of X-ray diffractometry (XRD), transmission electron microscope (TEM), UV–Vis diffusion reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS) indicate the successfully incorporation of Co(OH) 2 co-catalysts onto the surface of TiO 2 nanosheet photocatalysts . Further photocatalytic hydrogen evolution experiments illustrate that all Co(OH) 2 decorated TiO 2 samples show higher rate of hydrogen production performance than pure TiO 2 sample and the composite sample with Co(OH) 2 loading amount of 0.5mol% presents the highest photocatalytic hydrogen production activity of 746.93 μmol g −1 ·h −1 . It is indicated that plate-like Co(OH) 2 particle act as an electron collector, which leads to photo-generated electrons transfer from TiO 2 to Co(OH) 2 , and therefore enhance the photocatalytic activity . Based on above results, a possible mechanism is proposed and further verified by surface photovoltage spectra (SPV).
Jianghao Xing,Yuqi Yang,Wei Zhang,Jianqin Yan,Haisheng Qian,Jiqing Hao,Liang Cheng,Xianwen Wang
Tumors have become the biggest obstacle to human health, and there are various treatment methods at present. Photothermal therapy (PTT) is usually ineffective and does not inhibit tumor progression due to the inability of the lasers to penetrate deeply. Therefore, most existing studies chose a 1064 nm laser with stronger penetrating power; meanwhile, studies have shown that the inclusion of harmful free radicals can significantly improve the antitumor efficacy. Herein, TiO nanosheets (NSs) were creatively prepared and encapsulated with an alkyl radical generator {2,2′-azobis[2-(2-imidazoline-2-yl)propane] dihydrochloride, [AIPH]} in sodium alginate (ALG) hydrogel for effective tumor killing by PTT and pairing with dangerous free radicals. TiO NSs were obtained by the liquid-phase exfoliation method, together with AIPH, which were in situ coencapsulated multifunctional hydrogels formed by the combination of Ca2+ and ALG. This ALG hydrogel could enrich TiO NSs and AIPH at the tumor site for a long time, and through the excellent photothermal properties of TiO NSs, AIPH could slowly and effectively generate alkyl radicals at the tumor site, which, in turn, gave it a better antitumor effect compared with that of TiO NSs in the deep hypoxic environment of the tumor. The AIPH + TiO + ALG hydrogel has distinctive anticancer capabilities based on the results of both in vivo and in vitro experiments. This material also has good biosafety. By combining PTT and free radical treatment, this work provides a novel therapeutic method to achieve oxygen-independent free radical production and enhance therapeutic efficacy.
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