Molecular Engineering of Conjugated Polymers for Biocompatible Organic Nanoparticles with Highly Efficient Photoacoustic and Photothermal Performance in Cancer Theranostics

Conjugated polymer nanoparticles (CP NPs) are emerging candidates of "all-in-one" theranostic nanoplat-forms with dual photoacoustic imaging (PA) and photothermal therapy (PTT) functions. So far, very limited molecular design guidelines have been developed for achieving CPs with highly efficient PA and PTT performance. Herein, by designing CP1, CP2, and CP3 using different electron acceptors (A) and a planar electron donor (D), we demonstrate how the D A strength affects their absorption, emission, extinction coefficient, and ultimately PA and PTT performance. The resultant CP NPs have strong PA signals with high photo thermal conversion efficiencies and excellent biocompatibility in vitro and in vivo. The CP3 NPs show a high PA signal to background ratio of 47 in U87 tumor-bearing mice, which is superior to other reported PA/PTT theranostic agents. A very small IC50 value of 0.88 mu g/mL (CP3 NPs) was obtained for U87 glioma cell ablation under laser irradiation (808 nm, 0.8 W/cm(2), 5 min). This study shows that CP NP based theranostic platforms are promising for future personalized nanomedicine.

共轭聚合物纳米粒子（CP NPs）是具有光声成像（PA）和光热治疗（PTT）双重功能的“一体化”诊疗纳米平台的新兴候选者。到目前为止，对于实现具有高效PA和PTT性能的CPs，所制定的分子设计准则非常有限。在此，通过使用不同的电子受体（A）和平坦的电子给体（D）设计CP1、CP2和CP3，我们展示了D - A强度如何影响它们的吸收、发射、消光系数，并最终影响PA和PTT性能。所得的CP NPs具有强的PA信号、高光热转换效率以及在体外和体内优异的生物相容性。在荷U87肿瘤小鼠中，CP3 NPs显示出47的高PA信号与背景比，这优于其他已报道的PA/PTT诊疗试剂。在激光照射（808 nm，0.8 W/cm²，5分钟）下，对于U87胶质瘤细胞消融，获得了非常小的半抑制浓度值（IC50）为0.88μg/mL（CP3 NPs）。这项研究表明，基于CP NP的诊疗平台对于未来的个性化纳米医学是有前景的。