Photothermal therapy (PTT) is a promising approach for effective cancer treatment because of its non-invasive procedure, low toxicity to normal tissues, and high tumour ablation efficiency. Developing a PTT agent with precise tumour imaging capabilities is an essential prerequisite for effective PTT. In this study, we developed a bifunctional near-infra-red (NIR) fluorescent conjugate consisting of chitosan oligosaccharide lactate (COL) and the ZW800-1 NIR fluorophore (COL-ZW). We demonstrate that this conjugate is easy to use and that it is an effective theranostic agent for fluorescence-guided photothermal treatment. The temperature of COL-ZW increased by 62.3 °C after NIR laser irradiation (1.1 W/cm2) for 5 min in HT-29 tumour-bearing mice. The HT-29 tumours targeted by COL-ZW showed a remarkable decrease in tumour volume until a week after photothermal treatment. These in vivo results demonstrate that the bifunctional COL-ZW generates strong fluorescence and light-triggered PTT in tumour sites, indicating successful fluorescence-guided PTT. Importantly, no tumour recurrence or treatment-induced toxicity was observed after a single dose of COL-ZW with laser irradiation. Therefore, a combinatorial treatment with COL-ZW and NIR laser irradiation could serve as a promising strategy for photothermal cancer therapy.

中文翻译：

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近红外荧光壳聚糖寡糖乳酸盐，用于靶向癌症成像和光热疗法。

光热疗法（PTT）由于其非侵入性程序，对正常组织的低毒性以及高的肿瘤消融效率，是一种有效的癌症治疗方法。开发具有精确肿瘤成像功能的PTT剂是有效PTT的必要前提。在这项研究中，我们开发了一种由壳聚糖寡糖乳酸（COL）和ZW800-1 NIR荧光团（COL-ZW）组成的双功能近红外（NIR）荧光共轭物。我们证明了这种共轭物易于使用，并且它是用于荧光引导的光热处理的有效治疗剂。在HT-29荷瘤小鼠中，NIR激光照射（1.1 W / cm2）5分钟后，COL-ZW的温度升高了62.3°C。用COL-ZW靶向的HT-29肿瘤显示出明显的肿瘤缩小，直到光热治疗后一周。这些体内结果表明，双功能COL-ZW在肿瘤部位产生强荧光和光触发的PTT，表明成功的了荧光引导的PTT。重要的是，在单剂量的COL-ZW激光照射后，未观察到肿瘤复发或治疗引起的毒性。因此，采用COL-ZW和NIR激光照射的组合治疗可以作为光热癌治疗的有前途的策略。单剂量COL-ZW激光照射后未观察到肿瘤复发或治疗诱导的毒性。因此，采用COL-ZW和NIR激光照射的组合治疗可以作为光热癌治疗的有前途的策略。单剂量COL-ZW激光照射后未观察到肿瘤复发或治疗诱导的毒性。因此，采用COL-ZW和NIR激光照射的组合治疗可以作为光热癌治疗的有前途的策略。