Wang Jie, Lin Fuxing, Chen Jinxing, Wang Mozhen, Ge Xuewu
CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
J Mater Chem B. 2015 Dec 21;3(47):9186-9193. doi: 10.1039/c5tb01314c. Epub 2015 Nov 11.
The combination of NIR photothermal therapy and chemotherapy is considered as the promising technique for future cancer therapy. The key point of this technique is the design and synthesis of photothermal agents with high-efficiency photothermal effects and high chemical drug loading capacity. Herein, submicron-sized raspberry-like hollow-structured polypyrrole microspheres (H-PPy) were facilely prepared through in situ polymerization of pyrrole on monodispersed polystyrene (PS) template microspheres with a diameter of 220 nm, followed by the chemical etching of PS templates. The prepared H-PPy microspheres show rapid and remarkable photothermal effects in water under NIR laser irradiation (808 nm) only for 5 min. Further, a model small molecular drug, (S)-(+)-camptothecin (CPT), was loaded into the void core by a simple dispersion-permeation process through the micro-pores on the raspberry-like PPy shell, with a loading capacity of 0.14 mg/(mg H-PPy). The MTT assay and the in vitro NIR-laser triggered release behavior indicated that pure H-PPy microspheres have good biosafety, but the release of loaded CPT into H-PPy microspheres can be achieved with remarkable spatial/temporal resolution after NIR laser irradiation, which results in excellent synergistic effect of photothermal and chemical ablation on HeLa cells, as proved by fluorescence microscopy. This work provides convenient synthesis of a promising cancer therapy agent with high drug-loading capacity and efficient NIR light photothermal effects, which can perfectly achieve the synergistic NIR photothermal therapy and chemotherapy of PPy microspheres.
近红外光热疗法与化疗相结合被认为是未来癌症治疗的一种有前景的技术。该技术的关键在于设计和合成具有高效光热效应和高化学药物负载能力的光热剂。在此，通过在直径为220nm的单分散聚苯乙烯（PS）模板微球上原位聚合吡咯，随后化学蚀刻PS模板，简便地制备了亚微米级树莓状中空结构聚吡咯微球（H-PPy）。所制备的H-PPy微球在808nm近红外激光照射下仅5分钟就能在水中显示出快速且显著的光热效应。此外，通过一个简单的分散渗透过程，将模型小分子药物（S）-（+）-喜树碱（CPT）通过树莓状PPy壳上的微孔负载到中空核中，负载量为0.14mg/（mg H-PPy）。MTT试验和体外近红外激光触发释放行为表明，纯H-PPy微球具有良好的生物安全性，但负载到H-PPy微球中的CPT在近红外激光照射后能够以显著的时空分辨率实现释放，这导致对HeLa细胞的光热和化学消融具有优异的协同效应，荧光显微镜证实了这一点。这项工作提供了一种方便的合成方法，制备出一种有前景的癌症治疗剂，具有高药物负载能力和高效的近红外光光热效应，能够完美实现PPy微球的协同近红外光热疗法和化疗。
