Construction of 2D Antimony(III) Selenide Nanosheets for Highly Efficient Photonic Cancer Theranostics

Photonic cancer hyperthermia has been considered to be one of the most representative noninvasive cancer treatments with high therapeutic efficiency and biosafety. However, it still remains a crucial challenge to develop efficient photothermal nanoagents with satisfactory photothermal performance and biocompatibility, among which two-dimensional (2D) ultrathin nanosheets have recently been regarded as the promising multifunctional theranostic agents for photothermal tumor ablation. In this work, we report, for the first time, on the construction of a novel kind of photothermal agents based on the intriguing 2D antimony(III) selenide (Sb₂Se₃) nanosheets for highly efficient photoacoustic imaging-guided photonic cancer hyperthermia by near-infrared (NIR) laser activation. These Sb₂Se₃ nanosheets were easily fabricated by a novel but efficiently combined liquid nitrogen pretreatment and freezing-thawing approach, which were featured with high photothermal-conversion capability (extinction coefficient: 33.2 L g^-1 cm^-1; photothermal-conversion efficiency: 30.78%). The further surface engineering of these Sb₂Se₃ ultrathin nanosheets with poly(vinyl pyrrolidone) (PVP) substantially improved the biocompatibility of the nanosheets and their stability in physiological environments, guaranteeing the feasibility in photonic antitumor applications. Importantly, 2D Sb₂Se₃-PVP nanosheets have been certificated to efficiently eradicate the tumors by NIR-triggered photonic tumor hyperthermia. Especially, the biosafety in vitro and in vivo of these Sb₂Se₃ ultrathin nanosheets has been evaluated and demonstrated. This work meaningfully expands the biomedical applications of 2D bionanoplatforms with a planar topology through probing into new members (Sb₂Se₃ in this work) of 2D biomaterials with unique intrinsic physiochemical property and biological effect.