Jiang Yu, Duan Xingchen, Bai Junhua, Tian Hongkun, Ding Dan, Geng Yanhou
Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China; School of Materials Science and Engineering and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, Tianjin, 300072, PR China.
State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials, Ministry of Education and College of Life Sciences, Nankai University, Tianjin, 300071, China.
Biomaterials. 2020 Oct;255:120179. doi: 10.1016/j.biomaterials.2020.120179. Epub 2020 Jun 10.
Photothermal conversion nanoagents based on conjugated polymers (CPs) are attracting increasing attention for in vivo disease theranostics and high-performing ones are in urgent pursuit. Herein, we report a new and non-donor-acceptor approach to photothermal conversion CPs that combine several merits including low bandgaps, strong near-infrared absorption, low intersystem crossing rate and non-emissive nature. Three CPs based on 6,7; 6',7'-fused isoindigos (nIIDs), i.e., P2IIDV, P3IIDV and P4IIDV that have optical bandgaps of 1.30, 1.22 and 1.17 eV, respectively, are synthesized. The nanoparticles (NPs) of the CPs in water are prepared via nanocoprecipitation, which are non-fluorescent due to the rapid intramolecular twisting in the CP backbone within NPs, enabling most of the excitation energy flow to generate heat. The photothermal conversion efficiencies of the NPs as measured under irradiation at 808, 880 and 980 nm are 62.4%, 40.5% and 15.8% for P2IIDV, 65.1%, 41.0% and 38.9% for P3IIDV and 71.5%, 48.9% and 41.7% for P4IIDV, which are significantly higher than indocyanine green and many popularly reported photothermal conversion materials. In vivo studies using xenograft 4T1 tumor-bearing mouse model demonstrate that the P4IIDV NPs can serve as a rather effective photothermal conversion nanoagent for enhanced photoacoustic imaging and photothermal therapy of tumors.
基于共轭聚合物（CPs）的光热转换纳米剂在体内疾病诊疗方面正吸引着越来越多的关注，人们迫切需要高性能的此类纳米剂。在此，我们报道了一种新型的、非供体-受体型的光热转换CPs方法，该方法兼具多种优点，包括低带隙、强近红外吸收、低系间窜越率和非发光特性。合成了三种基于6,7；6',7'-稠合异吲哚酮（nIIDs）的CPs，即P2IIDV、P3IIDV和P4IIDV，它们的光学带隙分别为1.30、1.22和1.17 eV。通过纳米共沉淀法制备了CPs在水中的纳米颗粒（NPs），由于NPs内CP主链中分子内的快速扭曲，这些纳米颗粒无荧光，使得大部分激发能用于产热。在808、880和980 nm照射下测得的P2IIDV NPs的光热转换效率分别为62.4%、40.5%和15.8%，P3IIDV NPs的分别为65.1%、41.0%和38.9%，P4IIDV NPs的分别为71.5%、48.9%和41.7%，这些效率显著高于吲哚菁绿和许多已报道的光热转换材料。使用异种移植4T1荷瘤小鼠模型进行的体内研究表明，P4IIDV NPs可作为一种相当有效的光热转换纳米剂，用于增强肿瘤的光声成像和光热治疗。
