Department of Chemical Engineering, National Taiwan University of Science and Technology , Taipei 10607, Taiwan, Republic of China.
Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan, Republic of China.
ACS Appl Mater Interfaces. 2017 Apr 26;9(16):13887-13899. doi: 10.1021/acsami.7b01599. Epub 2017 Apr 14.
We propose a one-pot microwave-assisted pyrolysis method for fabrication of magnetofluorescent carbon quantum dots (MFCQDs), using a combination of waste crab shell and three different transition-metal ions, Gd, Mn, and Eu, referred to as Gd@CQDs, Mn@CQDs, and Eu@CQDs, respectively. Chitin from waste crab shell acted not only as a carbon source but also as a chelating ligand to form complexes with transition-metal ions. Gd@CQDs exhibited a high r relaxivity of 4.78 mM·s and a low r/r ratio of 1.33, suggesting that they show excellent potential as a T contrast agent. Mn@CQDs and Eu@CQDs showed high r relaxivity values of 140.7 and 28.32 mM·s, respectively, suggesting their potential for use as T contrast agents. Further conjugation of Gd@CQDs with folic acid (FA) enabled specific targeting to folate receptor-positive HeLa cells, as confirmed via in vitro magnetic resonance and fluorescence imaging. Doxorubicin (DOX) was selected as a model drug for conjugation with FA-Gd@CQDs. The as-prepared nanocomposites showed significantly higher cytotoxicity toward HeLa cells than free DOX. No apparent cytotoxicity was observed in vivo (zebrafish embryos) or in vitro (cell viability), suggesting that MFCQDs show potential for development as diagnostic probes or theranostic agents.
我们提出了一种微波辅助的一锅法制备磁荧光碳量子点（MFCQDs）的方法，使用了废弃蟹壳和三种不同的过渡金属离子（Gd、Mn 和 Eu）的组合，分别称为 Gd@CQDs、Mn@CQDs 和 Eu@CQDs。废弃蟹壳中的甲壳素不仅作为碳源，还作为螯合剂与过渡金属离子形成配合物。Gd@CQDs 表现出高 r 弛豫率 4.78 mM·s 和低 r/r 比 1.33，表明它们具有作为 T1 造影剂的优异潜力。Mn@CQDs 和 Eu@CQDs 的 r 弛豫率值分别高达 140.7 和 28.32 mM·s，表明它们具有作为 T1 造影剂的潜力。进一步将 Gd@CQDs 与叶酸（FA）偶联，通过体外磁共振和荧光成像证实了其对叶酸受体阳性 HeLa 细胞的特异性靶向。选择阿霉素（DOX）作为与 FA-Gd@CQDs 偶联的模型药物。所制备的纳米复合材料对 HeLa 细胞的细胞毒性明显高于游离 DOX。在体内（斑马鱼胚胎）或体外（细胞活力）均未观察到明显的细胞毒性，表明 MFCQDs 有望开发为诊断探针或治疗药物。
