Multifunctional TiO2/C nanosheets derived from 3D metal-organic frameworks for mild-temperature-photothermal-sonodynamic-chemodynamic therapy under photoacoustic image guidance

The sythesis of composite nanosheets with multiple functions remains signifcantly challenging. In this study, we developed multifunctional H-TiO2/C-PEG nanosheets as theranostic agents combining sonodynamic therapy and a low-power-mild-photothermal-enhanced Fenton effect. The two-dimensional HTiO2/C composite nanosheets were synthesized by reducing metal-organic frameworks (MOF)-derived from H-TiO2/C composite nanoparticles (NPs) by hydrogen. The resulting H-TiO2/C was introduced into polyethylene (PEG) to improve water solubility and increase the size of the particles to allow a higher level of H-TiO2/C accumulation at the tumor site through the enhanced permeability and retention effect. The H-TiO2/C nanosheets had excellent sonodynamic therapy (SDT) effects and could also achieve lowpower mild photothermal therapy guided by photoacoustic imaging with high photothermal conversion efficiency (g = 56.2 %). Also, a strong photothermal effect accelerated the rate of the Fenton reaction to enhance the efficacy of chemodynamic therapy (CDT). Importantly, combination therapy can achieve signifcant antitumour efficacy whilst the strong biocompatibility of the particles minimising adverse effects in normal cells. This study provides a promising strategy for the development of novel two-dimensional composite materials that are safe and have multifunctional diagnostic and therapeutic properties. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

In this study, the authors developed multifunctional H-TiO2/C-PEG nanosheets for theranostic applications. The nanosheets exhibited excellent sonodynamic therapy and low-power mild photothermal therapy. They also enhanced the efficacy of chemodynamic therapy through a strong photothermal effect. This study provides a promising strategy for the development of safe and multifunctional composite materials with diagnostic and therapeutic properties.