调控供电子策略简易制备近红外二区有机小分子光学诊疗试剂

有机小分子凭借着明确的化学结构、出色的生物相容性、优异的可重复性等诸多优势被广泛应用于光学诊疗领域. 然而, 目前报道的有机小分子存在合成步骤复杂、成像波长位于近红外一区(NIR-I)、光热转换效率及单线态氧产率低等缺陷, 严重限制了其诊疗效果. 基于此, 本工作以吡咯并吡咯二酮作为缺电子单元、分别以苯、苯胺、邻苯二胺作为供电子单元, 通过一步偶联反应简易制备得到三种有机小分子DPP-0、DPP-2、DPP-4, 进一步利用纳米沉淀法制备得到对应的水溶性纳米粒子DPP-0 NPs、DPP-2 NPs和DPP-4 NPs. 研究发现, 随着氨基数量的增加, 纳米粒子吸收/发射均发生了红移, 其中DPP-4 NPs具有良好的NIR-I吸收能力且其最大荧光发射达到了近红外二区(NIR-II)区域, 表明可以通过改变供电子单元策略实现光学性能的调控. 在单一激光照射下, DPP-4 NPs可以同时产生NIR-II荧光信号、过高热及单线态氧, 其光热转换效率和单线态氧产率分别高达40.2%及34.3%, 可成功应用于肿瘤深层次NIR-II荧光成像诊断及高效光热/光动力联合治疗.     

荧光碳点的合成、性质和应用

与传统半导体发光材料相比,荧光碳点作为一种新型的碳纳米发光材料,因其优异的生物相容性、良好的发光性能、简单的合成工艺、低廉的成本等优点而备受关注。荧光碳点在生物荧光标定、医学传感器、光诊疗剂以及发光器件等方面具有广阔的应用潜力。本文重点阐述了荧光碳点的合成方法、显微结构分析、荧光机理及应用的最新成果,希望为荧光碳点合成与应用研究的发展提供参考。     

聚合物纳米光诊疗剂的制备与应用新进展

共轭聚合物纳米颗粒是由π-共轭有机聚合物组成的尺寸在1~100nm范围内的新型有机纳米材料。与传统的有机小分子、半导体量子点和无机纳米材料相比,聚合物纳米颗粒具有光学性质特殊、结构多样、表面易修饰和生物相容性好等优点,因而被广泛应用于生物成像、传感与检测、载药和治疗等领域。本文主要围绕聚合物纳米颗粒的制备方法、性质结构和生物相容性等方面,重点介绍了聚合物纳米颗粒作为光诊疗剂在荧光成像、光声成像,以及光动力和光热治疗领域的研究进展,并对聚合物纳米颗粒的发展前景和未来面临的挑战进行了探讨。     

Upconverting Carbon Nanodots from Ethylenediaminetetraacetic Acid (EDTA) as Near-Infrared Activated Phototheranostic Agents

This work describes the synthesis of nitrogen-doped carbon nanodots (CNDs) synthesized from ethylenediaminetetraacetic acid (EDTA) as a precursor and their application as luminescent agents with a dual-mode theranostic role as near-infrared (NIR) triggered imaging and photodynamic therapy agents. Interestingly, these fluorescent CNDs are more rapidly and selectively internalized by tumor cells and exhibit very limited cytotoxicity until remotely activated with a NIR illumination source. These CNDs are excellent candidates for phototheranostic purposes, for example, simultaneous imaging and therapy can be carried out on cancer cells by using their luminescent properties and the in situ generation of reactive oxidative species (ROS) upon excitation in the NIR range. In the presence of CNDs, NIR remote activation induces the in vitro killing of U251MG cells. Through the use of flow imaging cytometry, we have been able to successfully map and quantify the different types of cell deaths induced by the presence of intracellular superoxide anions ( ^. O₂⁻) and hydrogen peroxide (H₂O₂) ROS generated in situ upon NIR irradiation.