Biocompatibility and Bioimaging Potential of Fruit-Based Carbon Dots

Abstract

Photo-luminescent carbon dots (CD) have become promising nanomaterials and their synthesis from natural products has attracted attention by the possibility of making the most of affordable, sustainable and, readily-available carbon sources. Here, we report on the synthesis, characterization and bioimaging potential of CDs produced from diverse extensively produced fruits: kiwi, avocado and pear. The in vitro cytotoxicity and anticancer potential of those CDs were assessed by comparing human epithelial cells from normal adult kidney and colorectal adenocarcinoma cells. In vivo toxicity was evaluated using zebrafish embryos given their peculiar embryogenesis, with transparent embryos developing ex-utero, allowing a real-time analysis. In vitro and in vivo experiments revealed that the synthesized CD presented toxicity only at concentrations of ≥1.5 mg mL−1. Kiwi CD exhibited the highest toxicity to both cells lines and zebrafish embryos, presenting lower LD50 values. Interestingly, despite inducing lower cytotoxicity in normal cells than the other CDs, black pepper CDs resulted in higher toxicity in vivo. The bio-distribution of CD in zebrafish embryos upon uptake was investigated using fluorescence microscopy. We observed a higher accumulation of CD in the eye and yolk sac, avocado CD being the ones more retained, indicating their potential usefulness in bio-imaging applications. This study shows the action of fruit-based CDs from kiwi, avocado and pear. However the compounds present in these fruit-based CDs and their mechanism of action as a bioimaging agent need to be further explored.

Natural carbon-based quantum dots and their applications in drug delivery: A review

“…To avoid any expensive precursors NCDs are prepared from fruit peels or juices (lemon, grapes, lychees, avocado, kiwi etc. ), vegetables, milk, and willow bark, which have abundance of polyphenolic and phenolic compounds that exhibit antioxidant properties which further enrich their synthesis [ 31 , 32 ]. This green synthesis approach is highly sustainable, minimizes waste production, highly biocompatible, environmental friendly, easy handling and non-toxic.…”

A Review on Multifunctional Carbon-Dots Synthesized From Biomass Waste: Design/ Fabrication, Characterization and Applications

“…According to Bi et al, extracted C-Dots have almost no toxicity which is safe and theoretically high biocompatibility at a dosage 20 mg L −1 (Bi et al, 2017). Most of the C-Dots possess low toxicity when the concentration of the C-Dots is as low as 2.5 mg ml −1 (Kang et al, 2015) or 1 mg ml −1 (Dias et al, 2019) as indicated by some cytotoxicity studies. However, there is an instance where a high concentration (e.g.,100 mg L −1 ) of the C-Dots that shows minimal toxicity (Kavitha and Kumar, 2018).…”

Metabolomic Profiling Unveils the Impact of Non-Doped and Heteroatom-Doped Carbon Nanodots on Zebrafish (Danio rerio) Embryos

“…Another study was published where relevant findings were recorded on rare minnow embryos exposed to CNDs [ 17 ]. Dias et al pointed out that CNDs synthesized from different fruits (used as precursor material) exhibited different toxicity and caused various phenotype alterations on zebrafish embryos and hinting that the elemental composition of CNDs can alter their effect [ 18 ]. To examine whether this is the case with several CNDs, our team examined the effect of non-doped, nitrogen-doped (N-doped), and nitrogen/sulfur codoped (N,S-codoped) CNDs on zebrafish [ 19 ].…”