Herein, we report the synthesis of Au nanoparticles (AuNPs) in chitosan (CTS) solution by chemically reducing HAuCl₄. CTS was further functionalized with glycidyl methacrylate (chitosan-g-glycidyl methacrylate/AuNP, CTS-g-GMA/AuNP) to improve the mechanical properties for cellular regeneration requirements of CTS-g-GMA/AuNP. Our nanocomposites promote excellent cellular viability and have a positive effect on cytokine regulation in the inflammatory and anti-inflammatory response of skin cells. After 40 days of nanocomposite exposure to a skin wound, we showed that our films have a greater skin wound healing capacity than a commercial film (TheraForm^®), and the presence of the collagen allows better cosmetic ave aspects in skin regeneration in comparison with a nanocomposite with an absence of this protein. Electrical percolation phenomena in such nanocomposites were used as guiding tools for the best nanocomposite performance. Our results suggest that chitosan-based Au nanocomposites show great potential for skin wound repair.

The printing and dyeing industries generate wastewater containing toxic, hard-to-degrade organic dyes like methylene blue (MB). Recent research focuses on biodegradable, renewable materials such as cellulose-based absorbents to address this issue. This study investigates bacterial cellulose (BC) functionalized with citric acid as a sustainable adsorbent for MB removal. BC, a by-product of kombucha fermentation, is functionalized with citric acid, and its adsorption capacity is analyzed. BC production reaches 3.65 ± 0.16 g L⁻¹ by day 12. Using 0.05 g of functionalized BC (FBC) at pH 7, a maximum adsorption capacity of 13.22 ± 1.27 mg g⁻¹ is achieved for MB at 600 mg L⁻¹ over 60 min. The adsorption mechanism is complex, with both pseudo-first- and pseudo-second-order models fitting well at 20 °C, 40 °C, and 70 °C. The carboxyl groups of citric acid bind to the hydroxyl groups of cellulose fibers via esterification, altering the material’s charge, reactivity, thermal, and crystallinity properties. This functionalization enhances BC’s adsorption capacity, making it a promising material for bioremediation in circular systems.

Sargassum spp. affects the Caribbean shores; thus, its remotion or valorization is a priority. This work aimed to synthesize a low-cost magnetically retrievable Hg⁺² adsorbent functionalized with ethylenediaminetetraacetic acid (EDTA) based on Sargassum. The Sargassum was solubilized to synthesize by co-precipitation a magnetic composite. A central composite design was assessed to maximize the adsorption of Hg⁺². The solids yield magnetically attracted mass, and the saturation magnetizations of the functionalized composite were 60.1 ± 17.2%, 75.9 ± 6.6%, and 1.4 emu g⁻¹. The functionalized magnetic composite yielded 29.8 ± 0.75 mg Hg⁺² g⁻¹ of chemisorption after 12 h, pH 5, and 25 °C achieving 75% Hg⁺² adsorption after four reuse cycles. Crosslinking and functionalization with Fe₃O₄ and EDTA created differences in surface roughness as well as the thermal events of the composites. The Fe₃O₄@Sargassum@EDTA composite was a magnetically recovered biosorbent of Hg²⁺.

Electrostatic fermentation avoids the cellular redox imbalance of traditional fermentation, but knowledge gaps exist. This study explores the impact of electrostatic fermentation on the growth, volatile profile, and genetic response of Saccharomyces pastorianus Saflager S-23. The applied voltage (15 and 30 V) in the electrostatic fermentation system increased the growth and substrate utilization of S. pastorianus while decreasing ethanol production. The aromas typically associated with traditional fermentation, such as alcoholic, grape, apple, and sweet notes, were diminished, while aromas like roses, fruits, flowers, and bananas were augmented in electrostatic fermentation. RNA-seq analysis revealed upregulation of genes involved in cell wall structure, oxidoreductase activity, and iron ion binding, while genes associated with protein synthesis, growth control, homeostasis, and membrane function were downregulated under the influence of applied voltage. The electrostatic fermentation system modulates genetic responses and metabolic pathways in yeast, rendering it a promising method for tailored beer production. Demonstrating feasibility under industrial-scale and realistic conditions is crucial for advancing towards commercialization.

Hexavalent chromium (Cr(VI)) is a highly toxic, non-biodegradable, and carcinogenic heavy metal. Its continuous release into aquatic ecosystems demands efficient, low-cost adsorbents. In this study, orange peel and peanut shell residues were thermally modified at 250 °C to enhance Cr(VI) remediation. Structural characterization confirmed that low-temperature calcination transforms raw agroindustrial wastes into functional biochars with a chemical architecture primed for cooperative Cr(VI) removal. N₂ physisorption revealed a hierarchical mesoporous network with average pore diameters of 30.6 nm (calcined orange peel) and 15.4 nm (calcined peanut shell), despite low specific surface areas. Batch adsorption experiments demonstrated that removal kinetics reached equilibrium within 5 min for the modified biochars. Isotherm modeling showed that the adsorption process was best described by the Freundlich and Sips models. The calculated Sips heterogeneity factors (β_S > 1) provided evidence of a cooperative multi-layer adsorption mechanism, attributed to the induced mesoporosity: initial chemisorption at high-energy sites facilitates the continuous anchoring of additional Cr(VI) ions without premature saturation. Ultimately, this study demonstrates that low-temperature calcination is a viable strategy to transform agricultural waste into kinetically efficient, cooperative adsorbents for wastewater treatment.