Abstract：
Artificial colloidal motors capable of converting various external energy into mechanical motion, have emerged as attractive photosensitizer (PS) nanocarriers with good deliverability for photodynamic therapy. However, photoactivated 3O2-to-1O2 transformation as the most crucial energy transfer of the photodynamic process itself is still challenging to convert into autonomous transport. Herein, we report on PS-loaded thiophane-containing semiconducting conjugated polymer (SCP)-based polymer colloidal motors with asymmetric geometry for photodynamic-regulated propulsion in the liquid. The asymmetrical presence of the SCP phases within the colloidal motors would lead to significant differences in the 3O2-to-1O2 transformation and 1O2 release manners between asymmetrical polymer phases, spontaneously creating asymmetrical osmotic pressure gradients across the nanoparticles for powering the self-propelled motion under photodynamic regulation. This photoactivated energy-converting behavior can be also combined with the photothermal conversion of the SCP phases to create two energy gradients exerting diffusiophoretic/thermophoretic force on the colloidal motors for achieving multimode synergistic propulsion. This unique motile feature endows the light-driven PS nanocarriers with good permeability against various physiological barriers in the tumor microenvironment for enhancing antitumor efficacy, showing great potential in phototherapy.
摘要：
能够将各种外部能量转化为机械运动的人造胶体马达，已成为有吸引力的光敏剂（PS）纳米载体，具有良好的光动力疗法的可输送性。然而,光活化的3O2到1O2的转化作为光动力学过程本身最关键的能量转移仍然具有挑战性，要转化为自主运输。在这里，我们报告了带有PS负载的含硫烷的半导体共轭聚合物（SCP）的基于聚合物的胶体马达，其几何形状不对称，可在液体中进行光动力调节推进。胶体马达内SCP相的不对称存在将导致不对称聚合物相之间3O2到1O2转化和1O2释放方式的显著差异。自发地在纳米粒子上产生不对称的渗透压梯度，以在光动力调节下为自推进运动提供动力。这种光活化的能量转换行为也可以与SCP相的光热转换相结合，以产生两个能量梯度，在胶体马达上施加扩散泳动/热泳力，以实现多模协同推进。这种独特的运动特征赋予光驱动PS纳米载体对肿瘤微环境中的各种生理屏障具有良好的渗透性，以增强抗肿瘤功效。在光疗中显示出巨大的潜力。
