Green Synthesis of Nano Zinc Oxide/Nanohydroxyapatite Composites Using Date Palm Pits Extract and Eggshells: Adsorption and Photocatalytic Degradation of Methylene Blue

Biopolymer Based Multifunctional Films Loaded with Anthocyanin Rich Floral Extract and ZnO Nano Particles for Smart Packaging and Wound Healing Applications

There are significant societal repercussions from our excessive use of plastic products derived from petroleum. In response to the increasing environmental implications of plastic wastes, biodegradable materials have been proven to be an effective means of mitigating environmental issues. Therefore, protein- and polysaccharide-based polymers have gained widespread attention recently. In our study, for increasing the strength of a biopolymer (Starch), we used ZnO dispersed nanoparticles (NPs), which resulted in the enhancement of other functional properties of the polymer. The synthesized NPs were characterized using SEM, XRD, and Zeta potential values. The preparation techniques are completely green, with no hazardous chemicals employed. The floral extract employed in this study is Torenia fournieri (TFE), which is prepared using a mixture of ethanol and water and possesses diverse bioactive features and pH-sensitive characteristics. The prepared films were characterized using SEM, XRD, FTIR, contact angle and TGA. The incorporation of TFE and ZnO (SEZ) NPs was found to increase the overall nature of the control film. The results obtained from this study confirmed that the developed material is suitable for wound healing and can also be used as a smart packaging material.

Synergistic Anticandidal Activities of Greenly Synthesized ZnO Nanomaterials with Commercial Antifungal Agents against Candidal Infections

The high occurrence of mycological resistance to conventional antifungal agents results in significant illness and death rates among immunodeficient patients. In addition, the underprivileged therapeutic results of conventional antifungal agents, besides the potential toxicity resulting from long term therapy necessitate the fabrication of efficient antimicrobial combinations. Hence, the objective of the present investigation is to synthesize, characterize and investigate the anticandidal action of green zinc oxide nanoparticles (ZnO-NPs) formulated using Camellia sinensis leaf extract against three candidal pathogens. The eco-friendly synthesized ZnO-NPs were characterized utilizing different physicochemical methods and their anticandidal potency was tested utilizing a disk diffusion assay. In this setting, the size of the biofabricated ZnO-NPs was detected using transmission electron microscope (TEM) micrographs, recording an average particle size of 19.380 ± 2.14 nm. In addition, zeta potential analysis revealed that the ZnO-NPs surface charge was -4.72 mV. The biogenic ZnO-NPs reveal the highest anticandidal activity against the C. tropicalis strain, demonstrating relative suppressive zones measured at 35.16 ± 0.13 and 37.87 ± 0.24 mm in diameter for ZnO-NPs concentrations of 50 and 100 μg/disk, respectively. Excitingly, Candida glabrata showed a high susceptibility to the biofabricated ZnO nanomaterials at both ZnO-NPs' concentrations (50 and 100 μg/disk) compared to the control. Moreover, the biosynthesized ZnO-NPs revealed potential synergistic effectiveness with nystatin and terbinafine antifungal agents against the concerned strains. The maximum synergistic efficiency was noticed against the C. glabrata strain, demonstrating relative synergistic percentages of 23.02 and 45.9%, respectively. The biogenic ZnO-NPs revealed no hemolytic activity against human erythrocytes revealing their biosafety and hemocompatibility. Finally, the high anticandidal effectiveness of biogenic ZnO-NPs against the concerned candidal pathogens, as well as potential synergistic patterns with conventional antifungal agents such as nystatin and terbinafine, emphasize the prospective application of these combinations for the fabrication of biocompatible and highly efficient antifungal agents.

Development of Plant Protein Derived Tri Angular Shaped Nano Zinc Oxide Particles with Inherent Antibacterial and Neurotoxicity Properties

The synthesis of nanometer-sized metallic nanoparticles utilizing bio-sources is one of the most cost-effective and ecologically friendly approaches. Nano-zinc oxide particles (N-ZnO Ps) were made using a simple green synthesis method using an aqueous zinc nitrate salt and Perilla frutescens crude protein as a protecting and reducing agent in the current work. UV-visible (UV-vis) spectrophotometry, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), (energy dispersive x-ray spectroscopy) EDX and high-resolution transmission electron microscopy (HR-TEM) were used to characterize the synthesized N-ZnO Ps. A distinctive UV-vis absorption peak was observed at 370 nm due to N-ZnO Ps. The SEM and HR-TEM pictures revealed N-ZnO Ps with a triangular form. The XRD pattern indicated the wurtzite structure of N-ZnO Ps. Nanoparticles exhibited a zeta potential of −11.3 mV. The antibacterial activity of N-ZnO Ps was tested against Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumonia) microorganisms. The N-ZnO Ps were non-toxic to HMC-3 human normal brain microglia cells; however, they exhibited a potential cytotoxic effect on the LN-18 human brain glioblastoma cell line. These results indicate that N-ZnOPs can act as promising antibacterial and anticancer treatments in the prevention of Glioblastoma.

Synthesis of Starch-Grafted Polymethyl Methacrylate via Free Radical Polymerization Reaction and Its Application for the Uptake of Methylene Blue

In this research, a new biodegradable and eco-friendly adsorbent, starch-grafted polymethyl methacrylate (St-g-PMMA) was synthesized. The St-g-PMMA was synthesized by a free radical polymerization reaction in which methyl methacrylate (MMA) was grafted onto a starch polymer chain. The reaction was performed in water in the presence of a potassium persulfate (KPS) initiator. The structure and different properties of the St-g-PMMA was explored by FT-IR, 1H NMR, TGA, SEM and XRD. After characterization, the St-g-PMMA was used for the removal of MB dye. Different adsorption parameters, such as effect of adsorbent dose, effect of pH, effect of initial concentration of dye solution, effect of contact time and comparative adsorption study were investigated. The St-g-PMMA showed a maximum removal percentage (R%) of 97% towards MB. The other parameters, such as the isothermal and kinetic models, were fitted to the experimental data. The results showed that the Langmuir adsorption and pseudo second order kinetic models were best fitted to experimental data with a regression coefficient of R² = 0.93 and 0.99, respectively.

Light-Activated Hydroxyapatite Photocatalysts: New Environmentally-Friendly Materials to Mitigate Pollutants

This review focuses on a reasoned search for articles to treat contaminated water using hydroxyapatite (HAp)-based compounds. In addition, the fundamentals of heterogeneous photocatalysis were considered, combined with parameters that affect the pollutants’ degradation using hydroxyapatite-based photocatalyst design and strategies of this photocatalyst, and the challenges of and perspectives on the development of these materials. Many critical applications have been analyzed to degrade dyes, drugs, and pesticides using HAp-based photocatalysts. This systematic review highlights the recent state-of-the-art advances that enable new paths and good-quality preparations of HAp-derived photocatalysts for photocatalysis.