Photoluminescent carbon nanotags from harmful cyanobacteria for drug delivery and imaging in cancer cells

Abstract

Using a simple method of mass production of green carbon nanotags (G-tags) from harmful cyanobacteria, we developed an advanced and efficient imaging platform for the purpose of anticancer therapy. Approximately 100 grams of G-tags per 100 kilograms of harmful cyanobacteria were prepared using our eco-friendly approach. The G-tags possess high solubility, excellent photostability, and low cytotoxicity (<1.5 mg/mL for 24 h). Moreover, doxorubicin-conjugated G-tags (T-tags; >0.1 mg/mL) induced death in cancer cells (HepG2 and MCF-7) in-vitro at a higher rate than that of only G-tags while in-vivo mice experiment showed enhanced anticancer efficacy by T-tags at 0.01 mg/mL, indicating that the loaded doxorubicin retains its pharmaceutical activity. The cancer cell uptake and intracellular location of the G- and T-tags were observed. The results indicate that these multifunctional T-tags can deliver doxorubicin to the targeted cancer cells and sense the delivery of doxorubicin by activating the fluorescence of G-tags.

Eco-friendly carbon-nanodot-based fluorescent paints for advanced photocatalytic systems

“…A high-resolution scan of the C1s region showed deconvolution of the C1s peaks present in the carbon atoms’ different functional groups [-C-C or -C-H (284.6 eV), -C-O(H) (286.2 eV), and C-O-C=O (287.3 eV) peaks in the C1s spectrum], as evidenced in Supplementary Fig. 4 and Supplementary Tables 1 and 22426. These functional groups signify the solubility of C-paints in water without further chemical modification.…”

“…These peaks revealed what was almost an amorphous carbon phase, which was attributed to the introduction of oxygen-containing groups by physico-chemical reaction24. The former peak corresponds to the interlayer spacing of ~3.8 Å, which is slightly longer than that between the (002) planes in bulk graphite (~3.5 Å)2324.…”

“…3). The peak at 1130 cm −1 is assigned to a –CH 2 stretching vibration232425. The absorption at 2850–3000 cm −1 is attributed to C-H stretching vibration.…”

“…The absorption at 2850–3000 cm −1 is attributed to C-H stretching vibration. The broad peaks at 3200–3600 cm −1 indicates O-H bonding vibration24, which results in the hydrophilicity of C-paints and improves their stability and dispersibility in water, without any further surface passivation23. The chemical bonding states of the functional carbon and oxygen groups of the C-paints were examined by XPS analysis.…”

“…C-paints are suitable for fabrication on CDs with efficient structures and properties, thanks to biocompatible PEG’s low price and eco-friendliness22. Previously, our group reported CD fabrication from food waste and harmful green microalgae by modified ultrasound irradiation2324. However, the CDs’ relatively low PL intensity and physical states significantly limits their application to various fluorescence-based optoelectronic devices.…”