Synthesis and characterization of mesoporous zinc oxide nanoparticles and evaluation of their biocompatibility in L929 fibroblasts

OBJECTIVES

This study aimed to synthesize and characterize mesoporous zinc oxide nanoparticles (ZnO NPs) and also to evaluate the cytotoxicity of mesoporous ZnO NPs on L929 mouse fibroblast cell lines using 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay.

MATERIALS AND METHODS

The synthesized mesoporous ZnO NPs were extensively characterized using X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectra (EDAX), Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS). The cytotoxicity of mesoporous ZnO NPs was assessed by MTT assay. The study groups for cytotoxicity assay were normal saline, 0.1% calcined mesoporous ZnO NP solution, 1% calcined mesoporous ZnO NP solution, 0.1% noncalcined mesoporous ZnO NP solution, 1% noncalcined mesoporous ZnO NP solution, 0.1% ZnO NP solution, 1% ZnO NP solution, 2% chlorhexidine, and phosphate-buffered saline (PBS). The percentages of mean ± standard deviation of viable cells were analyzed.

RESULTS

Characterization of mesoporous ZnO NPs revealed that all the particles were in a more or less spherical shape with a wide particle size distribution of 70-100 nm. TEM image showed the uniformed and aggregated ZnO NPs with a typical size of 10-15 nm. BET analysis showed a mesoporous structure for the prepared mesoporous ZnO NPs. According to the MTT assay, chlorhexidine had the lowest cell viability percentage. Cell viability percentages of 0.1% mesoporous ZnO NP solutions (calcined and noncalcined) were statistically, significantly higher than 0.1% ZnO NP solution (p < .05). Cell viability percentages of 0.1% calcined and noncalcined mesoporous ZnO NP solutions and 0.1% ZnO NP solution were statistically, significantly higher than the 1% solutions (p < .05).

CONCLUSION

Mesoporous ZnO NPs exhibited less cytotoxicity against L929 mouse fibroblast cell lines compared to CHX and ZnO NPs, hence are safe to use.

Measuring Physical Properties of Electrospun Nanofiber Mats for Different Biomedical Applications

Electrospun nanofiber mats are nowadays often used for biotechnological and biomedical applications, such as wound healing or tissue engineering. While most studies concentrate on their chemical and biochemical properties, the physical properties are often measured without long explanations regarding the chosen methods. Here, we give an overview of typical measurements of topological features such as porosity, pore size, fiber diameter and orientation, hydrophobic/hydrophilic properties and water uptake, mechanical and electrical properties as well as water vapor and air permeability. Besides describing typically used methods with potential modifications, we suggest some low-cost methods as alternatives in cases where special equipment is not available.

Adsorptive removal of multiple organic dyes from wastewater using regenerative microporous carbon: Decisive role of surface-active sites, charge and size of dye molecules

Present work addresses the synthesis of microporous activated carbon (SDAC) by a facile thermochemical conversion of teak sawdust powder. The high surface area (1999 m² g^-1), excellent microporosity (average pore size: 2.62 nm), and turbostratic carbon structure with intertwined graphitic domains make SDAC a highly efficient adsorptive material for the removal of organic pollutants. The spectroscopic analyses (FTIR, Raman, and XPS) and adsorption locator calculations revealed multiple interactions between organic dyes and SDAC adsorbent, i.e., electrostatic, π-π, n-π interactions, and hydrogen linkages. The size, chemical functionalities, aromatic rings, electronegative and heteroatoms in dye molecules, along with the surface-active sites, microstructured and textural features of SDAC adsorbent collectively governed the interaction pathways and adsorption efficiency. The calculated adsorption energy using Monte Carlo-based simulation annealing method signified faster and higher adsorption of malachite green than methylene blue dye at surface-active sites (-COOH, CO, C-OH, and π-electron-rich domains) of SDAC adsorbent, corroborating the experimental results. The batch-mode adsorptive separation results showed remarkably high adsorption efficiency (>99%) for industrial wastewater to remove cationic and anionic dyes together. The SDAC displayed significantly high adsorption of methylene blue dye (625 mg.g^-1) with excellent recyclability without measurable loss of adsorption efficiency even after ten cycles. The SDAC fixed-bed column showed a dye removal capacity of 594 mg.g^-1 at 90% breakthrough in a continuous-mode process signifying its applicability for a real-time industrial run. The excellent conformity between batch mode and fixed bed continuous column adsorption data, along with higher removal capacity and remarkable recyclability, promise the use of SDAC adsorbent for industrial wastewater treatment to remove multiple organic pollutants.

Oleophobic composite films based on multi-layer graphitic scaffolding

Free-standing films based on a plasma-exfoliated multi-layer graphitic material composite comprising polyelectrolyte and fluorosurfactant. Such materials show oleophobic/hydrophilic properties and application within oil–water separations.