Eco-benign synthesis of nano­gold chitosan-bacterial cellulose in spent ground coffee kombucha consortium: Characterization, microbiome community, and biological performance.

Biomaterials that are mediocre for cell adhesion have been a concern for medical purposes. In this study, we fabricated nano­gold chitosan-bacterial cellulose (CBC-Au) via a facile in-situ method using spent ground coffee (SGC) in a kombucha consortium. The eco-benign synthesis of monodispersed gold nanoparticles (Au NPs) in modified bacterial cellulose (BC) was successfully achieved in the presence of chitosan (CHI) and a symbiotic culture of bacteria and yeast (SCOBY). The dominant microbiome community in SGC kombucha were Lactobacillaceae and Saccharomycetes. Chitosan-bacterial cellulose (CBC) and CBC-Au affected the microfibril networks in the nano cellulose structures and decreased the porosity. The modified BC maintained its crystallinity up to 80 % after incorporating CHI and Au NPs. Depth profiling using X-ray photoelectron spectroscopy (XPS) indicated that the Au NPs were distributed in the deeper layers of the scaffolds and a limited amount on the surface of the scaffold. Aspergillus niger fungal strains validated the biodegradability of each scaffold as a decomposer. Bacteriostatically CBC-Au showed better antimicrobial activity than BC, in line with the adhesion of NIH-3T3 fibroblast cells and red blood cells (RBCs), which displayed good biocompatibility performance, indicating its potential use as a medical scaffold.

Fabrication and characterization of hybrid eco-friendly high methoxyl pectin/gelatin/TiO2/curcumin (PGTC) nanocomposite biofilms for salmon fillet packaging.

Hybrid eco-friendly nanocomposite films were fabricated by blending high-methoxyl pectin, gelatin, TiO2, and curcumin through the solution casting method. Various concentrations (0-5 wt%) of TiO2 nanoparticles (TNPs) and curcumin as an organic filler were added to the blend solutions. A high TNP concentration affected the surface morphology, roughness, and compactness of the films. Additionally, 3D mapping revealed the nanoparticle distribution in the film layers. Moisture content, water solubility, and light transmittance reduced dramatically with increasing TNP content, in accordance with the water vapor and oxygen permeabilities. X-ray diffraction revealed that the films were semicrystalline nanocomposites, and the thermal properties of the films increased when 5 wt% of TNPs was incorporated into the blend solution. Fourier-transform infrared and Raman analyses revealed interactions among biopolymers, nanoparticles, and organic fillers through hydrogen bonding. The shelf life of fresh salmon fillets was prolonged to six days for all groups, revealed by total viable counts and psychrotrophic bacteria counts, and the pH of the salmon fillets could be extended until the sixth day for all groups. Biodegradation assays demonstrated a significant weight loss in the nanocomposite films. Therefore, a nanocomposite film with 5 wt% TNPs could potentially be cytotoxic to NIH 3T3 cells.

Preparation, characterization, and desalination study of polystyrene membrane integrated with zeolite using the electrospinning method.

The novel composite membranes of Styrofoam (polystyrene) integrated with natural zeolite particles were produced using the electrospinning method for desalination purposes. The product was then characterized using FTIR, XRD, and TGA. Subsequently, the effect of different zeolite concentrations, namely 0, 5, 10, 15, 20, and 30 wt.% on its morphological structure and effectiveness was determined. Desalination of artificial seawater was carried out using the gravitational filtration principle to confirm the membrane's capabilities, after which its performance was evaluated using 4 wt.% NaCl solution. The morphological analysis showed that the composite membrane obtained has a smooth surface with microdomains on a few parts, which indicates the presence of zeolite. The result showed that the product integrated with 30 wt.% zeolites had the best performance in the desalination of artificial seawater. This was determined by comparing the conductivity value of the seawater before and after the process. The conductivity led to an 82.63% decrease using 30 wt.% zeolites. The developed polystyrene membrane embedded with zeolite has good thermal stability, hence, it can be used for desalination.