Antimicrobial carbon dots/pectin-based hydrogel for promoting healing processes in multidrug-resistant bacteria-infected wounds.

Multidrug-resistant (MDR) bacterial infections have become a significant threat to global healthcare systems. Here, we developed a highly efficient antimicrobial hydrogel using environmentally friendly garlic carbon dots, pectin, and acrylic acid. The hydrogel had a porous three-dimensional network structure, which endowed it with good mechanical properties and compression recovery performance. The hydrogel could adhere closely to skin tissues and had an equilibrium swelling ratio of 6.21, indicating its potential as a wound dressing. In particular, the bactericidal efficacy following 24-h contact against two MDR bacteria could exceed 99.99 %. When the hydrogel was applied to epidermal wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) on mice, a remarkable healing rate of 93.29 % was observed after 10 days. This was better than the effectiveness of the traditionally used antibiotic kanamycin, which resulted in a healing rate of 70.36 %. In vitro cytotoxicity testing and hemolysis assay demonstrated a high biocompatibility. This was further proved by the in vivo assay where no toxic side effects were observed on the heart, liver, spleen, lung, or kidney of mice. This eco-friendly and easy-to-prepare food-inspired hydrogel provides an idea for the rational use of food and food by-products as a wound dressing to control MDR bacterial infections.

Adsorption of aflatoxins and ochratoxins in edible vegetable oils with dopamine-coated magnetic multi-walled carbon nanotubes.

A new, green, and cost-effective magnetic solid-phase extraction of aflatoxins and ochratoxins from edible vegetable oils samples was developed using polydopamine-coated magnetic multi-walled carbon nanotubes (PDA@Fe3O4-MWCNTs) as the absorbent. PDA@Fe3O4-MWCNTs nanomaterials were prepared by chemical co-precipitation and in situ oxidation and self-polymerization of dopamine and was characterized. Factors affecting MSPE and the adsorption behavior of the adsorbent to mycotoxins were studied, and the optimal extraction conditions of MSPE and the complexity of the adsorption process were determined. Based on this, the magnetic solid-phase extraction-high-performance liquid chromatography-fluorescence detection method (MSPE-HPLC-FLD) was established for determining six mycotoxins [aflatoxin B1 (AFB1), AFB2, AFG1, and AFG2, and ochratoxin A (OTA) and OTB)] in vegetable oils. The recovery was 70.15%~89.25%, and RSD was ≤6.4%. PDA@Fe3O4-MWCNTs showed a high affinity toward aflatoxins and ochratoxins, allowing selective extraction and quantification of aflatoxins and ochratoxins from complex sample matrices.