Fluorescent xylitol carbon dots: A potent antimicrobial agent and drug carrier

Abstract

Biomolecular carbon dots (CDs) have immense potential for various industries due to exceptional bioactivity, biocompatibility, low toxicity, and biodegradability. In the present work xylitol (Xlt), a natural sweetener produced by microbial fermentation of sugarcane bagasse (71.98% conversion) has been used for CDs preparation by microwave-assisted carbonization in the presence of ethylene diamine (EDA). The resultant xylitol carbon dots (XCDs) were irregular shaped, rough with an average size of 8.88 nm and exhibiting fluorescence between 400 and 450 nm. The presence of EDA preserves the native chemical structure of Xlt even after exposure to microwaves. Purified XCDs were conjugated (AM-XCD) with ketoconazole and tetracycline for fungi and bacteria, respectively. In comparison to Xlt, XCDs have higher inhibitory potential and reduced dosage size of antimicrobials against Cryptococcus neoformans, Candida albicans, Streptococcus pyogenes, and Escherichia coli by 75%, 75%, 87.50%, and 50%, respectively. For Listeria monocytogenes and Salmonella typhi also inhibitory potential was increased by 14.68% and 21.38%. Increased efficacy advocated the improved drug delivery in the presence of XCDs. However, no inhibitory effect was recorded against DU145 (human prostate cancer) and HCT-15 (human colon adenocarcinoma) cell lines. The findings of the current work suggested the possible use of Xlt as an important antimicrobial agent besides an efficient drug carrier in healthcare.

Progress in microalgal mediated bioremediation systems for the removal of antibiotics and pharmaceuticals from wastewater

“…Wang et al, 2018). Advances in the field of healthcare science have brought with them improved longevity and a better lifestyle for humans along with increased consumption and irrational use of antimicrobial and pharmaceutical products (Ahuja et al, 2021;Silva et al, 2019). Most of these compounds undergo metabolic reactions within the human body (hydroxylation and cleavages); however, pharmacokinetic studies have revealed that most are not fully metabolized and instead are excreted via feces/urine in original form or as degradation products.…”