1. State Key Laboratory far Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering,Donghua University, Shanghai 201620, China;College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China;2. State Key Laboratory far Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering,Donghua University, Shanghai 201620, China;3. School of Medicine Science, Jiaxing University, Jiaxing 314001, China
Abstract:
Nanomaterials with intense near-infrared (NIR) absorption exhibit effective photon-to-thermal energy transfer capabilities and can generate heat to ablate cancer cells, thus playing a pivotal role in photothermal cancer therapeutics. Herein, hydrophilic flower-like bismuth sulfur (Bi2S3) superstructures with uniform size and improved NIR absorption were controllably synthesized via a facile solvothermal procedure assisted by polyvinylpyrrolidone (PVP), which could adjust the product morphology. Induced by an 808-nm laser, the as-prepared Bi2S3 nanoflowers exhibited much higher photothermal conversion efficiency (64.3%) than that of Bi2S3 nanobelts (36.5%) prepared in the absence of PVP. This can be attributed not only to the Bi2S3 nanoflower superstructures assembled by 3-dimensional crumpled-paper-like nanosheets serving as many laser-cavity mirrors with improved reflectivity and absorption of NIR light but also to the amorphous structures with a lower band gap. Thus, to achieve the same temperature increase, the concentration or laser power density could be greatly reduced when using Bi2S3 nanoflowers compared to when using Bi2S3 nanobelts, which makes them more favorable for use in therapy due to decreased toxicity. Furthermore, these Bi2S3 nanoflowers effectively achieved photothermal ablation of cancer cells in vitro and in vivo. These results not only supported the Bi2S3 nanoflowers as a promising photothermal agent for cancer therapy but also paved an approach to exploit new agents with improved photothermal efficiency.
