Zirconium and cerium dioxide fabricated activated carbon-based nanocomposites for enhanced adsorption and photocatalytic removal of methylene blue and tetracycline hydrochloride.

Activated carbon (AC) is a porous, amorphous form of carbon known for its strong adsorption capacity, making it highly effective for use in wastewater treatment. In this investigation, AC-based nanocomposites (NCs) loaded with zirconium dioxide and cerium dioxide nanoparticles (ZrO2/CeO2 NPs) were successfully synthesized for the effective elimination of methylene blue (MB) and tetracycline hydrochloride (TCH). The AC-ZrO2/CeO2 NCs have a size of 231.83 nm, a zeta potential of -20.07 mV, and a PDI value of 0.160. The adsorption capacities of AC-ZrO2/CeO2 NCs for MB and TCH were proved in agreement with the Langmuir isotherm and pseudo 1st order kinetic model, respectively. The maximum adsorption capacities were determined to be 75.54 mg/g for MB and 26.75 mg/g for TCH. Notably, AC-ZrO2/CeO2 NCs exhibited superior photocatalytic degradation efficiency for MB and TCH under sunlight irradiation with removal efficiencies reaching up to 97.91% and 82.40% within 90 min, respectively. The t1/2 for the photo-degradation process of MB and TCH were 11.55 min and 44.37 min. Analysis of active species trapping confirmed the involvement of hole (h+), superoxide anion (•O2-), and hydroxyl radical (•OH) in the degradation mechanism. Furthermore, the residual solution post-contaminant removal exhibited minimal toxicity towards Artemia salina and NIH3T3 cells. Importantly, the NCs did not exhibit antibacterial activity against tested pathogens post-absorption/degradation of TCH. Thus, AC-ZrO2/CeO2 NCs could be a promising nanomaterial for wastewater treatment applications.

Recent advances in photocatalytic nanomaterials for environmental remediation: Strategies, mechanisms, and future directions.

Innovative and efficient strategies are urgently needed for wastewater treatment and environmental remediation. The photocatalytic degradation properties of photo-responsive nanomaterials (NMs) have become a prime candidate due to their low negative impact and photo-adjustability. Photocatalytic NMs vary in their degradation of different pollutants depending on the type of synthetic material, excitation light source, and physicochemical properties. Essentially, photocatalytic NMs excited by light produce reactive oxygen species (ROS) or metal ions that can degrade complex structure pollutants. Therefore, this review summarises the recent advances of photocatalytic NMs in the environmental application within the last 3 years, focusing on the development schemes, structural analyses, photocatalytic mechanisms, and the degradation effects of dyes, antibiotics, pesticides, phenolic compounds, metals, hormones, and other contaminants. The limitations and future directions are also explained. This review hopes to provide a possible pathway for the subsequent development of novel and efficient photocatalytic NMs to cope with complex and variable polluted environments.

Effects of yellow and red bell pepper (paprika) extracts on pathogenic microorganisms, cancerous cells and inhibition of survivin.

The present work examined the biomedical value of red and yellow bell pepper extracts (YME and RME) in terms of antioxidant, antibacterial and anticancer activities by in vitro and virtual studies. The yield of extract was 3.49% for RME and 2.92% for YME. The level of total phenols and total flavonoids significantly varied between the type of extracts, and it was higher in RME than that in YME. The extracts showed promising DPPH and ABTS free radical scavenging rates. The extracts showed an excellent antibacterial activity. The minimal inhibitory concentration (MIC) of RME was 0.20 mg mL-1 for Bacillus cereus, 0.30 mg mL-1 for Escherichia coli, 0.50 mg mL-1 for Staphylococcus aureus and 0.60 mg mL-1 and for Pseudomonas aeruginosa, while the MIC of YME was 0.40 mg mL-1 for B. cereus, 0.40 mg mL-1 for E. coli, 0.50 mg mL-1 for S. aureus, and 0.60 mg mL-1 for P. aeruginosa. TEM results demonstrated the cellular damage induced by RME in B. cereus biofilm. The RME did not show any cytotoxicity in normal NIH3T3 cells, but at 125 µg mL-1 did a strong cytotoxicity in human lung cancer cell line A549 as evident by cytotoxicity assay, ROS and AO/EB staining. The virtual biological examination indicated that ß-carotene from RME was a potential compound with higher docking energy against both targeted enzymes and proteins as - 14.30 for LpxC and - 15.59 for survivin. Therefore, it is recommended that RME is a better functional food with novel biomedical properties and it deserves further evaluation for its the novel molecules against multidrug resistant pathogens.

Mycosynthesis, characterization, anticancer and antibacterial activity of silver nanoparticles from endophytic fungus Talaromyces purpureogenus.

Background: Biogenic silver nanoparticles (AgNPs) have wider range of biomedical applications. The present work synthesized Tp-AgNPs using mycelial extract of endophytic fungus Talaromyces purpureogenus (MEEF), characterized, and analyzed for antibacterial, anti-proliferation and cell wounding healing activities. Methods: The synthesized Tp-AgNPs were characterized by UV-visible spectrophotometer (UV-Vis), field emission transmission electron microscopy (FETEM) with energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), particle size analysis (PSA) and X-ray diffraction (XRD). Further, antibacterial activity was determined by Kirby-Bauer test and anti-proliferation activity was tested in human lung carcinoma A549 by water-soluble tetrazolium and flow cytometer assay. In addition, cell wounding healing activity was determined by scratch assay. Results: UV-Vis results displayed a strong absorption peak from 390 nm to 420 nm, which indicated the successful synthesis of Tp-AgNPs. FETEM-EDS results indicated the round and triangle shaped Tp-AgNPs with the average size of 25 nm in accordance with PSA. FTIR analysis indicated the involvement of various functional molecules from MEEF in the synthesis of Tp-AgNPs. XRD result proved nature of Tp-AgNPs as a high-quality crystal. The Tp-AgNPs significantly inhibited the growth of bacterial pathogens at the minimal inhibitory concentration of 16.12 µg.mL-1 for Gram+, and 13.98 µg.mL-1 for Gram- bacteria. Further, Tp-AgNPs (2 µg.mL-1) showed a strong anti-proliferation effect in A549. Interestingly, Tp-AgNPs was not cytotoxic to normal NIH3T3 cells. In addition, the NPs exhibited a strong cell wounding healing activity. Conclusion: This work biosynthesized AgNPs with strong antibacterial, anticancer and cell wound healing properties using endophytic fungus T. purpureogenus.