用于肿瘤光热作用的多功能金纳米颗粒-脂质体杂合系统研究

In this study, we plan to construct a biodegradable gold nanoparticles-liposome hybrid system (AuNP-Lip) to solve the transport and metabolic problems of photothermal nano-materials in the human body and restrain the resistance to hyperthermia in cancer cells. The system consists of a thermal-sensitive liposome core and a gold shell composed of small gold nanoparticles covered on its surface. It has the plasma absorption at 800 nm and the photothermal effect in the tissue absorption window. As meanwhile, a chemotherapy drug norcantharidin was encapsulated in the lipsome core to inhibit the heat shock response of cancer cells. During the anti-tumor photothermal therapy，the gold shell assembled on the surface of AuNP-Lip could be broken into small particles which can be bio-metabolized through the liver and kidney irradiation upon NIR laser irradiation. At the same time, norcantharidin encapsulated in liposome core could be released into cytoplasma and restrain the resistance to hyperthermia in cancer cells. We establish a fluorescence microscopic controllable irradiation platform to study light-controlled release effect of AuNP-Lip in tumor cells and in vitro cell and in vivo animal experiments are conducted to evaluate the effect of multi-functional synergistic photothermal effects and the mechanism of AuNP-Lip, providing a new tool for anti-tumor photothermal therapy and its clinical application.

本研究拟构建一种人体可代谢的纳米金-脂质体杂合系统(AuNP-Lip)，尝试解决肿瘤光热治疗中光热纳米材料在人体内的输运和代谢问题，同时通过削弱肿瘤细胞热休克反应以增强光热作用效果。该系统由温敏脂质体核心和其表面包覆的金纳米壳层组成，具备在800nm处的等离子吸收特性和组织吸收窗口内的光热作用。同时温敏脂质体核心中包裹一种能够抑制肿瘤细胞热休克效应的化疗药物去甲斑蝥素。在近红外激光照射下，AuNP-Lip表面的金纳米壳层产生光热作用使温敏脂质体核心破裂自身重新分解为能够通过肝肾功能排出体外的小粒径金纳米颗粒，脂质体核心中包裹的去甲斑蝥素也可释放到肿瘤细胞胞浆中以协同增强光热作用效果。研究中通过搭建荧光显微可控光照平台研究肿瘤细胞中AuNP-Lip的光控释放效果，通过细胞和动物模型评估其多效协同光热作用效果及机制，为肿瘤光热治疗研究和临床应用提供新的工具。

光热疗法与普通抗癌药物治疗相比能够独立于肿瘤类型，可以克服肿瘤细胞的多重耐药性，且仅在光照区域内触发治疗效果而没有全身毒性，因此是一种极具潜力皮肤癌等浅表肿瘤的治疗方法。但由于目前所研制的光热纳米材料存在所须光照阈值能量高易损伤正常皮肤组，同时体内代谢不可控的问题而难以获得临床应用。本项目构建了一种可代谢的纳米金-脂质体杂合系统(简称AuNP-Lip)尝试解决肿瘤光热治疗中光热纳米材料在人体内的输运和代谢问题并削弱肿瘤细胞对热疗的抵抗反应以降低所须光照阈值能量。该系统由温敏脂质体核心和其表面包覆的由小粒径金纳米颗粒组成的金纳米壳层组成，且具备在800nm处的等离子吸收特性和组织吸收窗口内的光热作用。同时温敏脂质体核心中包裹一种能够抑制肿瘤细胞热休克效应的化疗药物去甲斑蝥素。实验证实了AuNP-Lip表面的金纳米壳层能够在810nm近红外激光200mW/cm2的皮肤可承受的光照阈值照射下20min内达到42℃左右，使温敏脂质体核心破裂自身重新分解为能够通过肝肾功能排出体外的5-6nm左右的小粒径金纳米颗粒，脂质体核心中包裹的去甲斑蝥素也可释放到肿瘤细胞胞浆中以显著削弱低热环境诱导下的肿瘤细胞的热休克效应并进一步诱导肿瘤细胞的凋亡，从而既可以实现低光照剂量下的显著光热作用效果也能够确保纳米材料治疗后的有效排出。研究中通过微区表征，光谱和光热检测等手段对制备的AuNP-Lip进行了详细的微观形貌、结构及光热性能等参数的表征，搭建了荧光显微可控光照平台研究了其在肿瘤细胞中的光热控释效果，通过分子生物学方法证明和阐释了其对肿瘤细胞热休克保护机制的削弱作用和机理，并通过细胞和裸鼠荷瘤模型评估其多效协同光热作用效果及体内代谢机制。为肿瘤光热治疗研究提供新工具，推动光热疗法的实际临床应用。