Horo Himali, Saha Muktashree, Das Himadree, Mandal Bishnupada, Kundu Lal Mohan
Centre for the Environment, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
Department of Bioscience & Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
Carbohydr Polym. 2022 Feb 1;277:118862. doi: 10.1016/j.carbpol.2021.118862. Epub 2021 Nov 6.
Carbon dots (CDs) have been a promising theranostic tool with high biocompatibility and a tailorable fluorescence profile. Herein, we report the synthesis of highly fluorescent amine-functionalized CDs from low molecular weight chitosan (LMWC) and silk-fibroin (SF) blends. The synthesized CDs were quasi-spherical in shape with a size of 3 ± 1.5 nm. A significant increase in fluorescent intensity and quantum yield was achieved upon increasing the SF content due to nitrogen doping. For inducing target specificity to cancer cells, biotin was covalently conjugated to the CDs, and the conjugation was determined by FTIR spectroscopy. The conjugate was further loaded with 5-fluorouracil (5-FU) as a model anti-cancer drug. The MTT assay showed increased cytotoxicity of the conjugated CDs in cancer cells compared to normal cells. The live-cell imaging in MCF-7 cell lines showed bright blue-colored fluorescence and increased internalization of the conjugated CDs than the non-conjugate ones due to receptor-mediated endocytosis.
碳点（CDs）是一种很有前景的诊疗工具，具有高生物相容性和可定制的荧光特性。在此，我们报告了由低分子量壳聚糖（LMWC）和丝素蛋白（SF）混合物合成高荧光胺功能化碳点的方法。合成的碳点呈准球形，尺寸为3±1.5纳米。由于氮掺杂，随着SF含量的增加，荧光强度和量子产率显著提高。为了诱导对癌细胞的靶向特异性，将生物素共价连接到碳点上，并通过傅里叶变换红外光谱法确定连接情况。该共轭物进一步负载了作为模型抗癌药物的5-氟尿嘧啶（5-FU）。MTT分析表明，与正常细胞相比，共轭碳点在癌细胞中的细胞毒性增加。MCF-7细胞系中的活细胞成像显示，由于受体介导的内吞作用，共轭碳点呈现亮蓝色荧光，并且其内化程度比非共轭碳点更高。
