The visualization of the treatment process in situ could facilitate to accurately monitor cancer photothermal therapy (PTT), and dramatically decrease the risk of thermal damage to normal cells and tissues, which represents a major challenge for cancer precision therapy. Herein, we prepare theranostic nanoprobes (NPs) for Förster resonance energy transfer (FRET)-based dual-modal imaging-guided cancer PTT, and clear visualization of the therapeutic process. The FRET-based theranostic NPs exhibit high FRET efficiency (88.2%), good colloidal stability, and tumor-targeting ability. Tumor tissue and surrounding blood vessels are visualized clearly by FRET-based NIR fluorescence imaging with a high signal-to-background ratio (14.5) and photoacoustic imaging with an excellent resolution at 24 h post injection of NPs. Under the guidance of dual-modal imaging, the NPs-induced photothermal effect selectively destructs cancer cells, simultaneously decreasing the FRET efficiency and leading to fluorescence and photoacoustic signal changes. The sensitive self-feedback process enables the in situ visualization of therapeutic process and precision guidance of in vivo cancer PTT. A high therapeutic efficacy and minimum side effects are achieved in C6 tumor-bearing nude mice, holding great promise for precision therapy and cancer theranostics.

中文翻译：

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基于福斯特共振能量转移的双模态治疗学纳米探针用于癌症光热疗法的原位可视化

现场治疗过程的可视化可以促进准确地监测癌症光热疗法（PTT），并显着降低对正常细胞和组织造成热损伤的风险，这代表了癌症精确疗法的主要挑战。在这里，我们准备用于基于福斯特共振能量转移（FRET）的双模态成像指导的癌症PTT的治疗诊断纳米探针（NPs），并清晰显示治疗过程。基于FRET的治疗性NP表现出较高的FRET效率（88.2％），良好的胶体稳定性和肿瘤靶向能力。NPs注射后24小时，通过具有高信噪比（14.5）的基于FRET的NIR荧光成像和具有出色分辨率的光声成像，可以清晰地看到肿瘤组织和周围血管。在双模式成像的指导下，NPs诱导的光热效应选择性破坏癌细胞，同时降低FRET效率并导致荧光和光声信号变化。灵敏的自我反馈过程可实现治疗过程的原位可视化和精确的指导体内癌症PTT。在带有C6肿瘤的裸鼠中实现了很高的治疗效果和最小的副作用，这为精密治疗和癌症治疗提供了广阔的前景。