Glutaraldehyde Cross-linked Membranes Research Articles

Comparison of Attachment and Proliferation of Human Gingival Fibroblasts on Different Collagen Membranes.

Background and Aim:Human gingival fibroblasts cultured on collagen membrane as an alternative treatment method used in tissue regeneration can lead to improved results in root coverage. The aim of this study was to evaluate the human gingival fibroblast proliferation and adhesion cultured on three types of collagen membranes.Materials and Methods:In this in vitro study, first-line human gingival fibroblast cells (HGF1-RT1) prepared and cultured on three membranes, including porcine pericardium (PP) (Jason, Botiss dental), human pericardium (HP) (Regen, Faravardeh Baft Iranian), and glutaraldehyde cross-linked (GC) (BioMend Extend, Zimmer Dental). Cell survival was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) after 24, 48, and 72 h and 7 days. Furthermore, morphology and adhesion of cells on the membrane were evaluated after 1 and 7 days by electron microscopy (scanning electron microscopy [SEM]). Statistical analysis was performed using two-way ANOVA with a significance level of 0.05.Results:Based on the results of MTT, cell survival on HP and PP membranes after 7 days significantly increased (P < 0.001), but for the GC membrane, it was reduced after 7 days (P = 0.031). Cell survival on HP and PP membranes did not differ (P = 1) and was more than GC (P < 0.001). SEM images showed that the adhesion of cells was better on HP and PP membranes than GC.Conclusion:The results of this study showed that natural collagen membranes (HP and PP) similarly support proliferation and adhesion of gingival fibroblasts. Survival and adhesion of gingival fibroblasts on cross-linked collagen membrane was less than two other membranes.

Permeation of ethanol and water vapors through chitosan membranes with ferroferric oxide particles cross-linked by glutaraldehyde and sulfuric(VI) acid

ABSTRACTChitosan membranes filled with different amount of ferroferric oxides and cross-linked by two different agents, i.e. sulfuric acid or glutaraldehyde, were prepared and the influence of iron oxide and cross-linking agents on ethanol and water permeation has been discussed. Ethanol and water vapors permeation rates were determined using the measuring cell method and mass transport coefficients were evaluated. It was found that permeation of water for both types of chitosan membranes after addition of magnetite gradually increased. Furthermore, the difference between ethanol/water permeation coefficients was larger for glutaraldehyde cross-linked membranes (CHGA) than for sulfuric acid cross-linked membranes (CHSA).

Characteristics of chitosan membranes modified by argon plasmas

Dense chitosan membranes were prepared and studied for surface modification using argon plasma produced at low pressures from 6.67–133.3 Pa with RF frequencies at a power ranging from 6–90 W. Glutaraldehyde and sulfuric acid in methanol were used as linking reagents before the plasma treatment. When the plasma density was fixed at conditions of 6 W and 49 W at 66.7 Pa, the membrane wettability was measured as a decrease in contact angle between the water drop and the membrane surface. Water swelling properties were increased in glutaraldehyde cross-linked membrane. It was found that the ionic permeability of the membranes did not depend linearly on the plasma density used. The density at 6 W was smaller than that produced at 49 W, but it increased the Cl − to K + permeability ratio of the membranes by 1.4–1.8 times, with the maximum increase found in glutaraldehyde cross-linked membranes. Results from AFM showed that plasma treatment caused roughness at the membrane surface, and consequently, the hydraulic permeability of the membranes was reduced. Moreover, results from ATR-FTIR showed a major increase in the absorption spectra of C O, C–H, and C–O functional groups. The results were similar for the sulfuric acid cross-linked and the control membrane. In contrast, a glutaraldehyde cross-linked membrane was not affected greatly by plasma treatment. This study indicates that surface modification by argon plasma leads to changes in filtration characteristics and ionic permeability of chitosan membranes.

Study on a Pyruvate Oxidase Biosensor Based on β-Cyclodextrin with Ferrocene as Electron-Transfer Mediator

A pyruvic acid biosensor was constructed by the use of ferrocene, which was included in the β-cyclodextrin as electron-transfer mediator, as well as glutaraldehyde cross-linked membrane of egg white and β-cyclodextrin as matrix of enzyme immobilization. Because of the excellent electron-transfer efficiency of ferrocene, the microenvironment from β-cyclodextrin, and also the inclusion complexation between them, the biosensor has quite good properties. The linear detection limiting of this biosensor decreased to 5.68 × 10−7 mol/L with excellent stability for 2.58% of relative standard deviation (RSD) during six individual detections.

Preparation and performance of poly(vinyl alcohol)/polyethyleneimine blend membranes for the dehydration of 1,4-dioxane by pervaporation: Comparison with glutaraldehyde cross-linked membranes

Dense pervaporation (PV) membranes were prepared by blending hydrophilic polymers, poly(vinyl alcohol) (PVA) and polyethyleneimine (PEI), which was then cross-linked by glutaraldehyde (GA) to assess their suitability for the separation of 1,4-dioxane–water mixtures. The membranes were characterized by FTIR to verify the formation of the ionic interaction, wide-angle X-ray diffraction (WAXD) to observe the effect of blending on crystallinity and thermal gravimetric analysis (TGA) to investigate the thermal stability and tensile testing to asses their mechanical stability. The effects of experimental parameters, such as feed composition, permeate pressure and membrane thickness on normalized flux and selectivity were determined for both the membranes and compared. Uncross-linked PVA/PEI and cross-linked PVA/PEI blend membranes were subjected to sorption studies to evaluate the extent of interaction and degree of swelling in a mixture of the two liquids. The membranes were found to have good potential for breaking the azeotrope of 18 wt.% concentration of water, cross-linked PVA/PEI membrane (90 μm thick) exhibited a lower flux (0.22 kg/(m 2 h)) and high selectivity (33.34) compared to PVA/PEI blend membrane. Separation factor was found to improve with decreasing feed water concentration, whereas flux decreased correspondingly. High permeate pressure caused a reduction in both flux and selectivity.