Extremely high inhibition activity of photoluminescent carbon nanodots toward cancer cells

Abstract

Highly water-soluble, biocompatible, and photoluminescent carbon nanodots (C-dots) having an average diameter 3.4 AE 0.8 nm and a quantum yield 4.3% are obtained from used green tea through grinding, calcination and centrifugation. The as-prepared C-dots are stable in high-ionic-strength media (e.g. 500 mM NaCl) and under light irradiation, allowing images of MCF-10A, MCF-7 and MDA-MB-231 cells to be recorded. The C-dots are mostly localized in the cell membranes and cytoplasms, with evidence of excitation-wavelength cell images. Relative to catechin, the C-dots provide greater inhibition efficiency of the growth of MCF-7 and MDA-MB-231 cancer cells, with lower toxicity for the MCF-10A normal cells. The inhibitory activity of C-dots is associated with the generation of greater amounts of reactive oxygen species. A prothrombin time (PT) assay of plasma samples reveals excellent biocompatibility of the C-dots. To the best of our knowledge, for the first time the C-dots provide inhibition efficiencies up to 80% and 82% for MCF-7 and MDA-MB-231 cancer cells, respectively, showing their high potential as cancer inhibitors.

Green Synthesis of Bifunctional Fluorescent Carbon Dots from Garlic for Cellular Imaging and Free Radical Scavenging

“…9-12 Among them, solvothermal methods using cheap and eco-friendly biomass such as green tea, sweet potatoes, honey, bamboo leaves, pomelo peel as the carbon sources to produce CDs have induced great interests due to their green chemistry nature. [13][14][15][16][17] The approach is also more costeffective as compared to those applied for synthesizing other fluorescence nanoparticles, such as noble metal nanoparticles and semiconductor QDs. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3 One of the most fascinating characteristics of CDs is their photoluminescent capability.…”

One Step Green Synthesis of Carbon Quantum Dots and Its Application Towards the Bioelectroanalytical and Biolabeling Studies

“…Till date there are so many methods adopted for the synthesis of carbon quantum dots including arc discharge [1], electrochemical synthesis [2,3], combustion/thermal/hydrothermal/acidic oxidation [4][5][6][7], cage-opening of fullerene [8], supported synthesis [9][10][11], microwave/ultrasonic [12,13], laser ablation [14,15] and electrochemical oxidation methods [16,17] and so on. Carbon quantum dots gained greater acceptance because of their wide application for instance in bioimaging [18,19], nanomedicine [20,21], photocatalysis [22,23], electrocatalysis [24,25], biosensing [26,27], and chemical sensing [28,29]. It was also used as Hg 2+ , Cu 2+ , Fe 3+ , Pb 2+ and Ag + sensors [30][31][32][33][34].…”

Green synthesis of fluorescent carbon dots from spices for in vitro imaging and tumour cell growth inhibition

“…In fact, very recently Pierrat et al claimed that the toxicity of C-dots is mainly determined by the synthesis protocol [30]. Also, it has been reported that some food-based C-dots show anticancer properties, which strongly relies on the starting material employed for the synthesis [31–32]. Keeping the aforementioned fascinating medicinal activities of selected spices in mind, highly fluorescent C-dots have been synthesized by a green one-pot hydrothermal route, using cinnamon, red chilli, turmeric and black pepper as starting materials.…”