Single-Layer MoS₂ Nanosheets with Amplified Photoacoustic Effect for Highly Sensitive Photoacoustic Imaging of Orthotopic Brain Tumors

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• 作者：Jingqin Chen ; Chengbo Liu ; Dehong Hu ; Feng Wang ; Haiwei Wu ; Xiaojing Gong ; Xin Liu ; Liang Song ; Zonghai Sheng and Hairong Zheng
• 刊名：Advanced Functional Materials
• 出版年：2016
• 出版时间：December 20, 2016
• 年：2016
• 卷：26
• 期：47
• 页码：8715-8725
• 全文大小：2274K
• ISSN：1616-3028

文摘

Photoacoustic (PA) imaging, as a fast growing technology that combines the high contrast of light and large penetration depth of ultrasound, has demonstrated great potential for molecular imaging of cancer. However, PA molecular imaging of orthotopic brain tumors is still challenging, partially due to the limited options and insufficient sensitivity of available PA molecular probes. Here, the direct formation of single-layer (S-MoS₂), few-layer (F-MoS₂), and multi-layer (M-MoS₂) nanosheets by the albumin-assisted exfoliation without further surface modifications is reported. It is demonstrated that the PA effect of the MoS₂ nanosheets is highly dependent on their layered nanostructures. Decreasing the number of nanosheet layers from M-MoS₂ to S-MoS₂ can both significantly enhance the near-infrared light absorption and improve the elastic properties of the nanomaterial, resulting in greatly amplified PA effect. The in vitro experiments demonstrate that the prepared S-MoS₂ with excellent biocompatibility can be efficiently internalized into U87 glioma cells, producing strong PA signals for highly sensitive detection of brain tumor cells, with a detection limit of ≈100 cells. Intravenous administration of S-MoS₂ to both U87 subcutaneous and orthotopic tumor-bearing mice shows highly efficient tumor retention and significantly enhanced PA contrast. Tumor tissue ≈1.5 mm below the skull can still be clearly visualized in vivo. Previous studies suggest that the fabricated S-MoS₂ with amplified PA effect have high potential to serve as an efficient nanoplatform for sensitive PA molecular imaging and hold promising prospect for translational medicine.