Synthesis, Characterization, and Applications of Carbon Dots for Determination of Pharmacological and Biological Samples: A Review

Carbon dots from purple sweet potato as a promising anti-inflammatory biomaterial for alleviating the LPS-induced inflammation in macrophages

This study synthesizes carbon dots derived from crude extracts of purple sweet potato (CPP-CDs) and evaluates its anti-inflammatory effects in a lipopolysaccharide (LPS) -induced acute inflammation model. Characterization revealed that CPP-CDs possess a uniform spherical structure and excellent photoluminescent properties. In vitro, CPP-CDs significantly inhibited the expression of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), reduced the accumulation of reactive oxygen species (ROS), suppressed pyroptosis, and facilitated the polarization of macrophages from the M1 phenotype to the M2 phenotype. In vivo, CPP-CDs significantly improved the survival rates of LPS-treated mice, mitigated tissue damage, and suppressed the levels of pro-inflammatory cytokines. Mechanistic studies indicated that CPP-CDs exert anti-inflammatory effects through the inhibition of the TLR4/NF-κB signaling pathway and the modulation of the NLRP3 inflammasome. Additionally, CPP-CDs exhibited excellent biocompatibility, with no significant toxicity observed in mice. This study provides strong evidence supporting the application of CPP-CDs as a novel anti-inflammatory material, highlighting their potential for acute inflammation treatment and expanding the possibilities for the development of carbon-dot-based anti-inflammatory therapies.

Gum Arabic: A Commodity with Versatile Formulations and Applications

Gum Arabic (GA), or acacia gum, refers to the dried exudate produced by certain Acacia trees. GA is composed mainly of a mixture of polysaccharides and glycoproteins, with proportions that can slightly differ from one species to another. It is commonly utilized in the food and pharmaceutical industries as a stabilizer or an emulsifier owing to its biocompatibility, hydrophilicity, and antibacterial properties. In addition, GA can be manipulated as it possesses many functional groups that can be used in grafting, cross-linking, or chemical modifications to add a new feature to the developed material. In this review, we highlight recent GA-based formulations, including nanoparticles, hydrogels, nanofibers, membranes, or scaffolds, and their possible applications in tissue regeneration, cancer therapy, wound healing, biosensing, bioimaging, food packaging, and antimicrobial and antifouling membranes.

High Luminescent Carbon Dots Derived from Fermented Beverages for Sensitive Sensing of Tartrazine in Foods

Highly luminescent carbon dots (CDs) derived from fermented beverages-kvass (K-CDs) were synthesized through a one-step hydrothermal method with ethylenediamine (EDA) as a surface passivation reagent. Purified K-CDs with a fluorescent quantum yield of 35.1% were obtained after a dialysis process. The K-CDs were characterized by TEM, FT-IR, XPS, fluorescence and UV-vis spectroscopy. The results indicated that K-CDs possess typical excitation wavelength-dependent blue fluorescence emission, and the strongest excitation and emission wavelengths are 350 nm and 440 nm, respectively. The great spectral overlap between the emission peak (440 nm) of K-CDs and the absorption peak (430 nm) of tartrazine (TAR) leads to an effective fluorescence quenching phenomenon by TAR through inner filter effect (IFE) and the calculated (lg(I0/I)) showed a linear response to TAR concentration in the range of 0.1-70 µM. The detection limit of the developed method is 23 nM for TAR, and the relative standard deviation (RSD) is 3.9% (c = 10 µM, n = 7). The fluorescent sensor for TAR based on K-CDs through the IFE mechanism possesses the characteristics of rapid, sensitive, and high selectivity. It has been successfully applied to detect of trace TAR in foods.