College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024, P. R. China.
J Mater Chem B. 2019 Apr 7;7(13):2130-2137. doi: 10.1039/c9tb00032a. Epub 2019 Feb 27.
Hollow carbon dots (HCDs), as drug carriers, and doxorubicin (DOX), as a model drug, were selected to prepare a HCDs-DOX-loading system. First, HCDs were prepared by a hydrothermal method and characterized by transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and nuclear magnetic resonance (C NMR), UV-vis absorption, Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopies (XPS). The HCDs were then used to load DOX. The drug-loading system of HCDs-DOX was characterized by zeta potential measurements, and UV-vis absorption and fluorescence spectroscopies. We then studied the drug loading, formation mechanism, cytotoxicity, in vitro release and pH-targeted properties. HCDs-DOX was found to have a high drug (DOX)-loading ratio (∼42.9%) and better sustained pH targeted-release and lower cytotoxicity than those of DOX. In the HCDs-DOX system, interactions between the HCDs and DOX were electrostatic resulting in the formation of -N[double bond, length as m-dash]C-via the coupling of -NH (on HCDs) and -C[double bond, length as m-dash]O (on DOX). In vitro release of HCDs-DOX conformed to the Weibull model and Fick diffusion, consistent with that of free DOX. We report, for the first time, that the: (i) functional groups on the HCD surfaces (not their hollow structure) play a key role in drug loading; (ii) the carrier (HCDs) did not change the in vitro release model or mechanism of DOX before and after loading by the HCDs.
中空碳点（HCDs）作为药物载体，阿霉素（DOX）作为模型药物，被选择用于制备 HCDs-DOX 负载系统。首先，通过水热法制备 HCDs，并通过透射电子显微镜（TEM）、粉末 X 射线衍射（PXRD）和核磁共振（C NMR）、紫外-可见吸收、傅里叶变换红外（FT-IR）和 X 射线光电子能谱（XPS）对其进行了表征。然后，将 HCDs 用于负载 DOX。通过zeta 电位测量、紫外-可见吸收和荧光光谱对 HCDs-DOX 药物负载系统进行了表征。然后，我们研究了药物负载、形成机制、细胞毒性、体外释放和 pH 靶向特性。与 DOX 相比，HCDs-DOX 具有较高的药物（DOX）负载比（约 42.9%）和更好的持续 pH 靶向释放以及更低的细胞毒性。在 HCDs-DOX 系统中，HCDs 和 DOX 之间的相互作用是静电的，导致 -N[双键，长度为 m-dash]C 通过 -NH（在 HCDs 上）和 -C[双键，长度为 m-dash]O（在 DOX 上）的偶联形成。HCDs-DOX 的体外释放符合 Weibull 模型和 Fick 扩散，与游离 DOX 一致。我们首次报道：（i）HCD 表面的官能团（而不是其中空结构）在药物负载中起着关键作用；（ii）载体（HCDs）在负载前后并未改变 DOX 的体外释放模型或机制。
