Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications , 9 Wenyuan Road, Nanjing 210023, China.
School of Chemical and Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, 637457 Singapore.
ACS Nano. 2017 Apr 25;11(4):4174-4182. doi: 10.1021/acsnano.7b01092. Epub 2017 Mar 21.
Upregulation of highly reactive oxygen species (ROS) such as hypochlorite (ClO) is associated with many pathological conditions including cardiovascular diseases, neuron degeneration, lung injury, and cancer. However, real-time imaging of ClO is limited to the probes generally relying on fluorescence with shallow tissue-penetration depth. We here propose a self-assembly approach to develop activatable and degradable photoacoustic (PA) nanoprobes for in vivo imaging of ClO. A near-infrared absorbing amphiphilic oligomer is synthesized to undergo degradation in the presence of a specific ROS (ClO), which integrates a π-conjugated but ClO oxidizable backbone with hydrophilic PEG side chains. This molecular architecture allows the oligomer to serve as a degradable nanocarrier to encapsulate the ROS-inert dye and self-assemble into structurally stable nanoparticles through both π-π stacking and hydrophobic interactions. The self-assembled nanoprobe exhibits sensitive and specific ratiometric PA signals toward ClO, permitting ratiometric PA imaging of ClO in the tumor of living mice.
活性氧（ROS）如次氯酸根（ClO）的上调与许多病理状况有关，包括心血管疾病、神经元变性、肺损伤和癌症。然而，ClO 的实时成像仅限于通常依赖于组织穿透深度较浅的荧光的探针。我们在这里提出了一种自组装方法，开发用于 ClO 体内成像的激活和可降解的光声（PA）纳米探针。合成了一种近红外吸收的两亲性低聚物，在特定 ROS（ClO）的存在下进行降解，该低聚物将共轭但可被 ClO 氧化的主链与亲水性 PEG 侧链集成在一起。这种分子结构允许低聚物作为可降解的纳米载体来封装 ROS 惰性染料，并通过π-π 堆积和疏水相互作用自组装成结构稳定的纳米颗粒。自组装的纳米探针对 ClO 表现出敏感和特异性的比率型 PA 信号，允许在活小鼠的肿瘤中进行 ClO 的比率型 PA 成像。
