A Perspective on Using Organic Molecules Composing Carbon Dots for Cancer Treatment.

Fluorescent Carbon dots (CDs) derived from biologically active sources have shown enhanced activities compared to their precursors. With their prominent potentiality, these small-sized (<10nm) nanomaterials could be easily synthesized from organic sources either by bottom-up or green approach. Their sources could influence the functional groups present on the CDs surfaces. A crude source of organic molecules has been used to develop fluorescent CDs. In addition, pure organic molecules were also valuable in developing practical CDs. Physiologically responsive interaction of CDs with various cellular receptors is possible due to the robust functionalization on their surface. In this review, we studied various literatures from the past ten years that reported the potential application of carbon dots as alternatives in cancer chemotherapy. The selective cytotoxic nature of some of the CDs towards cancer cell lines suggests the role of surface functional groups towards selective interaction, which results in over-expressed proteins characteristic of cancer cell lines. It could be inferred that cheaply sourced CDs could selectively bind to overexpressed proteins in cancer cells with the ultimate effect of cell death induced by apoptosis. In most cases, CDs-induced apoptosis directly or indirectly follows the mitochondrial pathway. Therefore, these nanosized CDs could serve as alternatives to the current kinds of cancer treatments that are expensive and have numerous side effects.

Comparison Direct Synthesis of Hyaluronic Acid-Based Carbon Nanodots as Dual Active Targeting and Imaging of HeLa Cancer Cells.

The present study explores the potential of carbon nanodots (CDs) synthesized from hyaluronic acid using microwave-assisted and furnace-assisted methods as bioimaging agents for cancer cells. The investigation on the effect of microwave-assisted and furnace-assisted times (2 min and 2 h) on determining CD character is dominantly discussed. Various CDs, such as HA-P1 and HA-P2 were, respectively, synthesized through the furnace-assisted method at 270 °C for 2 min and 2 h, whereas HA-M1 and HA-M2 were synthesized with the microwave-assisted method for 2 min and 2 h, respectively. Overall, various CDs were produced with an average diameter, with the maximum absorption of HA-P1, HA-P2, HA-M1, and HA-M2 at 234, 238, 221, and 217 nm, respectively. The photoluminescence spectra of these CDs showed particular emissions at 320 nm and excitation wavelengths from 340 to 400 nm. Several characterizations such as X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy reveal the CD properties such as amorphous structures, existence of D bands and G bands, and hydrophilic property supported with hydroxyl and carboxyl groups. The quantum yields of HA-M1, HA-M2, HA-P1, and HA-P2 were 12, 7, 9, and 23%, respectively. The cytotoxicity and in vitro activity were verified by a cell counting kit-8 assay and confocal laser scanning microscopy, which show a low toxicity with the percentage of living cells above 80%.