Key Laboratory of Photochemical Conversion and Optoelectronic Materials and City U-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Zhongguancun east road 29#, Beijing, 100190, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Chem Asian J. 2019 Jun 14;14(12):2162-2168. doi: 10.1002/asia.201900416. Epub 2019 May 28.
Carbon dots (CDs), a kind of phototheranostic agent with the capability of simultaneous bioimaging and phototherapy [i.e., photodynamic therapy (PDT) or photothermal therapy (PTT)], have received considerable attention because of their remarkable properties, including flexibility for surface modification, high biocompatibility, low toxicity and photo-induced activity for malignant tumor cells. Among numerous carbon sources, it has been found that natural biomass are good candidates for the preparation of CD phototheranostic agents. In this study, pheophytin, a type of Mg-free chlorophyll derivative and also a natural product with low toxicity, was used as a raw carbon source for the synthesis of CDs by using a microwave method. The obtained hydrophobic CDs exhibited a maximum near-infrared (NIR) emission peak at approximately 680 nm, and high singlet oxygen ( O ) generation with a quantum yield of 0.62. The self-assembled CDs from the as-prepared CDs with DSPE-mPEG2000 retained efficient O generation. The obtained carbon dot assembly was not only an efficient fluorescence (FL) imaging agent but also a smart PDT agent. Our studies indicated that the obtained hydrophilic CD assembly holds great potential as a new phototheranostic agent for cancer therapy. This work provides a new route for synthesis of CDs and proposes a readily available candidate for tumor treatment.
碳点（CDs）是一种同时具有生物成像和光疗（即光动力疗法（PDT）或光热疗法（PTT））能力的光疗试剂，由于其具有显著的特性，包括表面修饰的灵活性、高生物相容性、低毒性和对恶性肿瘤细胞的光诱导活性，因此受到了相当大的关注。在众多的碳源中，已经发现天然生物质是制备 CD 光疗试剂的良好候选物。在本研究中，脱镁叶绿酸，一种无镁叶绿素衍生物，也是一种具有低毒性的天然产物，被用作通过微波法合成 CD 的原始碳源。所得的疏水性 CDs 在大约 680nm 处表现出最大的近红外（NIR）发射峰，并且具有 0.62 的高单线态氧（ O ）生成量子产率。用 DSPE-mPEG2000 自组装所得的 CDs 保留了有效的 O 生成。所得的碳点组装物不仅是一种高效的荧光（FL）成像剂，也是一种智能 PDT 剂。我们的研究表明，所得的亲水性 CD 组装物作为癌症治疗的新型光疗试剂具有很大的潜力。这项工作为 CDs 的合成提供了一条新途径，并提出了一种用于肿瘤治疗的易得候选物。
