In Vivo Study of Nasal Bone Reconstruction with Collagen, Elastin and Chitosan Membranes in Abstainer and Alcoholic Rats

The aim of the present study was to evaluate the use of collagen, elastin, or chitosan biomaterial for bone reconstruction in rats submitted or not to experimental alcoholism. Wistar male rats were divided into eight groups, submitted to chronic alcohol ingestion (G5 to G8) or not (G1 to G4). Nasal bone defects were filled with clot in animals of G1 and G5 and with collagen, elastin, and chitosan grafts in G2/G6, G3/G7, and G4/G8, respectively. Six weeks after, all specimens underwent radiographic, tomographic, and microscopic evaluations. Bone mineral density was lower in the defect area in alcoholic animals compared to the abstainer animals. Bone neoformation was greater in the abstainer groups receiving the elastin membrane and in abstainer and alcoholic rats receiving the chitosan membrane (15.78 ± 1.19, 27.81 ± 0.91, 47.29 ± 0.97, 42.69 ± 1.52, 13.81 ± 1.60, 18.59 ± 1.37, 16.54 ± 0.89, and 37.06 ± 1.17 in G1 to G8, respectively). In conclusion, osteogenesis and bone density were more expressive after the application of the elastin matrix in abstainer animals and of the chitosan matrix in both abstainer and alcoholic animals. Chronic alcohol ingestion resulted in lower bone formation and greater formation of fibrous connective tissue.

Expansion of Nanosized MgSiO3/Chitosan Nanocomposite Structural and Spectroscopic for Loading Velosef by Nanomaterial Intervention

The aim of this study is to investigate the effect of different doses of Velosef in magnesium silica/chitosan nanocomposite in terms of structural, morphology, optical properties, and bioactivity. Loading Velosef in fine-sized magnesium silica/chitosan is an efficient engineering approach for drug delivery. The sol-gel process was used to prepare magnesium silica fine-sized before being blended into chitosan matrix, which acts as a potential morphogenetic biomaterial. The Velosef/magnesium silica/chitosan nanocomposites were characterized by XRD, TEM, SEM, FTIR, UV-absorption, and antimicrobial studies. The XRD was characteristic of the crystallinity degree of the MgO-SiO2/chitosan/Velosef nanocomposites with three maximum peaks at 26.37°, 33.34o, 36.9°. FTIR results indicated the structural change occurred with the Velosef sol-gel polymerization process. UV-absorbance reveals that the MgO-SiO2/chitosan nanocomposite appeared a high performance for loading Velosef at two absorption bands at 253 and 347 nm. The MgO-SiO2/Chitosan/Velosef nanocomposites showed considerable antimicrobial activity in opposition to the tested representative microorganisms. The maximum antimicrobial activity was obtained with MgO-SiO2/Chitosan against both Escherichia coli and Candida albicans (37 mm), while the minimum antimicrobial activity (30 mm) was recorded against B. mycoides and E. coli with control.

Chitosan-Ag nanoparticle antifungal activity against Fusarium sp., causal agent of wilt disease on chili

Chitosan is a polysaccharides compound derived from nature and has an amine group and a hydroxyl group that gives it unique physicochemical properties, which are polychationic and chelating agent. This shows that chitosan can be used as a stabilizer and reducer of Ag nanoparticles. Unlike other studies, chitosan that was used in this study was derived from Black Soldier Fly exuviae which has been through demineralization, deproteination, depigmentation, and deacetylation processes. This study aims to obtain an alternative environmentally friendly fungicide with Ag-chitosan nanoparticle formulation which has antifungal activity against Fusarium sp. that causes wilt disease in chili plants. We analysed particle size, functional group by FTIR, and antifungal test against Fusarium sp. on 1000, 750, 500, 250, and 100 ppm of chitosan-Ag nanoparticle. The chitosan-Ag nanoparticles have a particle size of 188.4 nm with a polydispersity index of 0.344. FTIR analysis showed that Ag+ ions are successfully grafted into the chitosan matrix. All the chitosan-Ag nanoparticle concentration tested showed significant results with negative and positive control, except the concentration of 100 ppm which is not significantly differ from negative control. The antifungal test showed a concentration of 750 ppm chitosan-Ag nanoparticles had a growth inhibition of 72.17%.

Removal of eriochrome black T from water using a chitosan/zeolite composite: a kinetic study

A composite material was prepared using chitosan and chabazite for the removal of Eriochrome T black dye from water. Scanning electron microscopy (SEM) analyses showed chabazite particles embedded in the chitosan matrix. Thermogravimetric analyses indicated that chitosan degrades chemically at temperatures above 225 °C; chabazite only experiences weight decrease due to moisture loss. Fourier transform infrared spectroscopy (FTIR) analyses on chitosan detected the presence of O-H, N-H, C-H, C-N and C-O bonds, protonated amino groups and saccharides. In chabazite, H2O molecules, T-O and O-T-O groups, where “T” corresponds to Si or Al atoms, isolated H-bonded O-H groups, and Si-O-Si groups were detected. In kinetic experiments, an 86 % decrease of the dye concentration in solution was achieved in approximately 500 minutes. The linearization method was used to evaluate the fit of the experimental data with the pseudo-first-order, pseudo-second order, Elovich and intra-particle diffusion adsorption kinetic models. The kinetic experiments showed that the sorption mechanism corresponds to a pseudo-second order model.

Heterogeneous Hybrid Nanocomposite Based on Chitosan/Magnesia Hybrid Films: Ecofriendly and Recyclable Solid Catalysts for Organic Reactions

Chitosan/magnesia hybrid films (CS-Mg) have been prepared via sol-gel process and employed as heterogeneous catalysts. An in situ generation of a magnesia network in the chitosan matrix was performed through hydrolysis/condensation reactions of magnesium ethoxide. The synthesized hybrid films were characterized using various analytical techniques, such as X-ray photo-electron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The hybrid films display excellent catalytic activities in Michael and Knoevenagel reactions via one pot or solvent-free approaches under microwave irradiation conditions. Chitosan/magnesia hybrid films, catalysed pyrimidine, benzochromene, coumarin and arylidene-malononitriles derivatives formation reactions occurred with highly efficient yields of 97%, 92%, 86% and 95% respectively. Due to the fact that the films are durable and insoluble in common organic solvents, they were easily separated and can be recycled up to five times without a considerable loss of their catalytic activity.