The State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
The State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Carbohydr Polym. 2020 Aug 1;241:116224. doi: 10.1016/j.carbpol.2020.116224. Epub 2020 Apr 28.
Polypyrroles have shown great potential in photoacoustic imaging and photothermal therapy owing to its excellent photothermal conversion capabilities. However, the synthesis of polypyrrole-based nano-assemblies which have colloidal stability in biological buffers requires a number of steps, including the polymerization of pyrrole monomers, self-assembly of polypyrrole-based copolymers, and even an additional step to increase the biocompatibility of the nano-assemblies. Herein, a "polymerization/assembly" two-in-one synthesis is proposed for the first time to achieve the one-step synthesis of a new family of polypyrrole-based nano-assemblies, dextran-polypyrrole nano-assemblies (Dex-PPy NAs), under ambient conditions and in aqueous media. In addition, the approach employs tetravalent cerium ions as initiators which can initiate the polymerization of pyrrole monomers through the initiation of free radicals from dextran molecular chains. The resultant Dex-PPy NAs have a photothermal conversion efficiency reaching as high as 41 % and an excellent photostability. More importantly, the NAs with controllable nanoscale dimensions display no signs of cytotoxicity in both in vitro and in vivo studies owing to their biocompatible dextran "shell". An in vivo study further confirmed that the Dex-PPy NAs have excellent real-time photoacoustic imaging and photothermal therapy capabilities for malignant tumors. Therefore, this study represents an important step towards the scalable synthesis of polypyrrole-based nano-assemblies with photothermal/photoacoustic dual capabilities and enhanced biocompatibility.
聚吡咯因其优异的光热转换能力，在光声成像和光热治疗方面显示出巨大的潜力。然而，合成具有胶体稳定性的基于聚吡咯的纳米组装体需要多个步骤，包括吡咯单体的聚合、基于聚吡咯的共聚物的自组装，甚至需要增加纳米组装体的生物相容性的额外步骤。在此，首次提出了“聚合/组装”二合一的合成方法，以在环境条件下和水介质中一步合成一系列新型的基于聚吡咯的纳米组装体，葡聚糖-聚吡咯纳米组装体（Dex-PPy NAs）。此外，该方法采用四价铈离子作为引发剂，通过葡聚糖分子链上自由基的引发，引发吡咯单体的聚合。所得的 Dex-PPy NAs 的光热转换效率高达 41%，具有优异的光稳定性。更重要的是，由于其具有生物相容性的葡聚糖“壳”，具有可控纳米尺寸的纳米组装体在体外和体内研究中均没有显示出细胞毒性的迹象。体内研究进一步证实，Dex-PPy NAs 具有优异的实时光声成像和光热治疗恶性肿瘤的能力。因此，这项研究代表了朝着可扩展合成具有光热/光声双重功能和增强生物相容性的基于聚吡咯的纳米组装体迈出的重要一步。
