Abstract

Introduction

Metastatic colorectal cancer (CRC) is complicated by chemotherapy-resistant cell populations. Oxaliplatin is used in heated intraperitoneal hyperthermic chemoperfusion (HIPEC) for treatment of disseminated CRC. Photothermal nanoparticles can provide focal heating to improve the response of CRC cells to oxaliplatin, by confining heating near individual cells. Reduction in cellular luciferase signal may allow single-cell-resolution recording of thermal dosimetry.

Methods

Oxaliplatin resistant (OxR) variants of luciferase-expressing CT26.WT-Fluc-Neo CRC cells were developed and their sensitivity to hyperthermia was evaluated. Polymer-based photothermal nanoparticles were developed, characterized and used to explore their potential for imparting a thermal dose to improve cell response to oxaliplatin. A correlation of thermal dose to intracellular luciferase activity was established using quantitative luminescence monitoring and microscopy.

Results

Luciferase-based monitoring of thermal dose within CT26 cell lines was validated within the ranges of 0.04–8.33 CEM43 for parental cells and 0.05–9.74 CEM43 for OxR CT26 cells. This was further confirmed using nanoparticle-induced hyperthermia, where the single-cell resolution of the thermal dose can be achieved. The nanoparticles enhance cell killing of resistant cells when combined with oxaliplatin and stimulated to generate heat.

Conclusion

Nanoparticle-based hyperthermia is effective for augmenting chemotherapy and can be coupled with reductions in CT26 luciferase expression to monitor thermal dose at single-cell resolution. The development of OxR CT26.WT-Fluc-Neo CRC cells sets the stage for pre-clinical evaluations to measure nanoparticle-induced hyperthermia to augment chemotherapy (Nano-HIPEC) in a chemotherapy-resistant model of disseminated CRC.

中文翻译：

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耐奥沙利铂的结直肠癌纳米热模型

摘要

介绍

转移性结直肠癌（CRC）伴随着化疗耐药细胞群的出现。奥沙利铂用于加热的腹膜内高温化学灌注（HIPEC），用于治疗弥散性CRC。通过限制单个细胞附近的加热，光热纳米颗粒可以提供聚焦加热，从而改善CRC细胞对奥沙利铂的反应。细胞荧光素酶信号的减少可以允许单剂量分辨率记录热剂量。

方法

开发了表达萤光素酶的CT26.WT-Fluc-Neo CRC细胞的奥沙利铂抗性（OxR）变体，并评估了其对热疗的敏感性。研发了基于聚合物的光热纳米颗粒，对其进行了表征并用于探索其赋予热剂量以改善细胞对奥沙利铂的反应的潜力。使用定量发光监测和显微镜建立了热剂量与细胞内荧光素酶活性的相关性。

结果

在外源细胞的0.04-8.33 CEM43和OxR CT26细胞的0.05-9.74 CEM43的范围内，验证了基于荧光素酶的CT26细胞系热剂量监测。使用纳米粒子诱导的高温进一步证实了这一点，其中可以实现热剂量的单细胞分辨率。当与奥沙利铂组合并被刺激产生热量时，纳米颗粒可增强耐药细胞的细胞杀伤力。

结论

基于纳米粒子的热疗可有效增强化疗效果，并可与CT26荧光素酶表达的降低相结合，以单细胞分辨率监测热剂量。OxR CT26.WT-Fluc-Neo CRC细胞的发展为在弥散性CRC耐药的化疗模型中测量纳米颗粒诱导的高热以增强化疗（Nano-HIPEC）奠定了临床前评估的舞台。