To improve the inherent defects of chemotherapy and photothermal therapy (PTT), we design a novel thermochromism-induced temperature self-regulation and alternating photothermal system based on iodine (I2)-loaded acetylated amylose nanohelix clusters (ILAA NHCs) under the guidance of molecular dynamic simulation in which I2 is loaded into the helical cavity of acetylated amylose (AA) by hydrophobic interaction. ILAA NHCs perform versatile photothermal conversion through their unique reversible thermochromism. Upon irradiation, I2 is gradually released and the ILAA NHCs turn into colorless. The laser is then penetrated deeply into the tissue for deep-seated heating, and the ILAA NHCs' color can be recovered by reversible thermochromism because of I2 reloading into the ILAA NHCs. When the process is repeated, the temperature can be controlled in a certain range. This alternating light-to-heat conversion significantly improve the effect of PTT. Meanwhile, I2 efficiently acts dual functions of chemotherapy and PTT. Results show that the photothermal depth by ILAA NHCs is 2.1-fold than other common photothermal agents (PTAs), and the irradiated region exhibits a lower surface temperature. In vitro and in vivo experiments both provide ILAA NHCs an excellent comprehensive antitumor effect with synergistic chemo/PTT, indicating versatile potential for tumor chemo/PTT.

中文翻译：

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热致变色诱导的温度自我调节和交替的光热纳米螺旋簇用于协同肿瘤化学/光热疗法。

为了改善化学疗法和光热疗法（PTT）的固有缺陷，我们在分子的指导下，基于负载碘（I2）的乙酰化直链淀粉纳米螺旋簇（ILAA NHC），设计了一种新的热致变色诱导的温度自调节和交替光热系统。动态模拟，其中I2通过疏水相互作用加载到乙酰化直链淀粉（AA）的螺旋腔中。ILAA NHC通过其独特的可逆热致变色性能可进行多种光热转换。照射后，I2逐渐释放，ILAA NHC变成无色。然后将激光深深地穿透到组织中，以进行深层次加热，并且由于I2重新加载到ILAA NHC中，可通过可逆的热致变色恢复ILAA NHC的颜色。重复此过程后，温度可以控制在一定范围内。这种交替的光热转换显着提高了PTT的效果。同时，I2有效地发挥了化疗和PTT的双重功能。结果表明，ILAA NHC的光热深度是其他常见光热剂（PTA）的2.1倍，并且受辐照区域的表面温度较低。体外和体内实验均为ILAA NHC提供了出色的综合抗肿瘤作用，并具有协同化学/ PTT的作用，表明肿瘤化学/ PTT具有广泛的潜力。照射区域的表面温度低。体外和体内实验均为ILAA NHC提供了优异的综合抗肿瘤作用，并具有协同化学/ PTT的作用，表明肿瘤化学/ PTT具有广泛的潜力。照射区域的表面温度低。体外和体内实验均为ILAA NHC提供了优异的综合抗肿瘤作用，并具有协同化学/ PTT的作用，表明肿瘤化学/ PTT具有广泛的潜力。