Effect of Red Mud and Rice Husk Ash-Based Geopolymer Composites on the Adsorption of Methylene Blue Dye in Aqueous Solution for Wastewater Treatment

In this study, geopolymer originating from locally industrial byproducts as red mud (RM) was successfully prepared in the presence of different loadings of rice husk ash (RHA) used for the adsorption of methylene blue (MB) in wastewater. During geopolymerization, various mixing amounts between RM and RHA were conducted when the weight ratio of binder solution/activated alkali-metal solution (Na2SiO3/ NaOH 7 M) was 2.5 and the curing temperature was set at 60 °C for 24 h. As a result, the surface area value of the prepared geopolymer composited with RHA at 0 and 60% was increased from 19.2 to 29.5 m2/g, while the BJH pore size of the prepared geopolymer was reduced to 6.68 and 5.76 nm, respectively. In the dye removal test, higher additions of RHA in the RM-geopolymer maintained better retention of the MB ion due to the increase in the adsorption binding site. The maximum uptake amount of dyes performed at pH 8 was changed from 6.59 to 10.74 mg/g, while RHA was from 0 to 60% after 180 min of immersion in MB solution. The adsorption isotherms well obeyed the Langmuir model, as the relative coefficient R2 was 0.999. Based on these, the initial agricultural waste as RHA and industrial byproducts as RM were valued as functional materials used for dye treatment in wastewater.

Catalytic dye degradation by novel phytofabricated silver/zinc oxide composites

Phytofabrication of the nanoparticles with exotic shape and size is an attractive area where nanostructures with noteworthy physicochemical and optoelectronic properties that can be significantly employed for photocatalytic dye degradation. In this study a medicinal plant, Plumbago auriculata leaf extract (PALE) was used to synthesize zinc oxide particles (ZnOPs) and silver mixed zinc oxide particles (ZnOAg1Ps, ZnOAg10Ps, ZnO10Ag1Ps) by varying the concentration of the metal precursor salts, i.e. zinc acetate and silver nitrate. The PALE showed significantly high concentrations of polyphenols, flavonoids, reducing sugar, starch, citric acid and plumbagin up to 314.3 ± 0.33, 960.0 ± 2.88, 121.3 ± 4.60, 150.3 ± 3.17, 109.4 ± 2.36, and 260.4 ± 8.90 μg/ml, respectively which might play an important role for green synthesis and capping of the phytogenic nanoparticles. The resulting particles were polydispersed which were mostly irregular, spherical, hexagonal and rod like in shape. The pristine ZnOPs exhibited a UV absorption band at 352 nm which shifted around 370 in the Ag mixed ZnOPs with concomitant appearance of peaks at 560 and 635 nm in ZnO10Ag1Ps and ZnOAg1Ps, respectively. The majority of the ZnOPs, ZnOAg1Ps, ZnOAg10Ps, and ZnO10Ag1Ps were 407, 98, 231, and 90 nm in size, respectively. Energy dispersive spectra confirmed the elemental composition of the particles while Fourier transform infrared spectra showed the involvement of the peptide and methyl functional groups in the synthesis and capping of the particles. The composites exhibited superior photocatalytic degradation of methylene blue dye, maximum being 95.7% by the ZnOAg10Ps with a rate constant of 0.0463 s−1 following a first order kinetic model. The present result clearly highlights that Ag mixed ZnOPs synthesized using Plumbago auriculata leaf extract (PALE) can play a critical role in removal of hazardous dyes from effluents of textile and dye industries. Further expanding the application of these phytofabricated composites will promote a significant complementary and alternative strategy for treating refractory pollutants from wastewater.

BiFeO3 immobilized within liquid natural rubber-based hydrogel with enhanced adsorption-photocatalytic performance

Semiconductor materials have shown a good photocatalytic behaviour for the photodegradation of organic pollutants. In this work, maleated liquid natural rubber (MLNR) based hydrogel supported bismuth ferrite (BiFeO₃) as photocatalyst was successfully synthesized by crosslinking with acrylic acid (AAc) assisted by the ultrasonication method to study the efficiency for the removal of methylene blue (MB) dye in wastewater. Response surface methodology (RSM) was used to optimize the parameters for adsorption of the methylene blue (MB) dye compound, whereby the effects of the initial concentration of MB and the adsorption time were examined to obtain a quadratic model for the respective hydrogel composite. The prepared composite sample was characterized by Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) and X-ray Diffraction (XRD) analysis. Remarkable improvement for removal of methylene blue (99% removal) was found within 3 h adsorption time with a MLNR/AAc-BiFeO₃ hydrogel composite as compared to the pristine hydrogel. A synergistic mode of dye removal by adsorption and photodegradation is proposed. Based on the isotherm and kinetic study conducted, it was found that Freundlich isotherm model and a pseudo second-order kinetic model was best fitted for adsorption of MB dye. The MLNR/AAc-BiFeO₃ composite maintains its removal efficiency after 5 cycles without the necessity of post-treatment separation. Therefore, it is crucial to note that the resultant low-cost MLNR/AAc-BiFeO₃ hydrogel composite in this study offers excellent potential for water and wastewater treatment applications with improved recyclability and recovery.

ID:2024 Synthesis and Characterization of PLGA-PEG Thymoquinone Nanoparticle and its Cytotoxicity Effects in Tamoxifen-resistant Breast Cancer Cells

Background: Drug resistance has been a continuous challenge in cancer treatment. The use of nanotechnology in the development of new cancer drugs has potential. One of the extensively studied compound is thymoquinone (TQ) and this work aims to compare two types of TQ-nanoformulation and its cytotoxicity towards resistant cancer cells. Methods: TQ-nanoparticles were prepared and optimized by using 2 different formulation with different drug to PLGA-PEG ratio (1:20 and 1:7) and different PLGA-PEG to pluronic F68 ratio (10:1 and 2:1). The morphology and size were determined using TEM and DLS. Characterization of particles were done using UV-VIS, ATR-IR, entrapment efficiency and drug release. The effects of drug, polymer and surfactants were compared between the two formulations. Cytotoxicity assay was performed using MTS assay. Results: TEM finding showed 96% of particles produced with 1:7 drug to PLGA-PEG were less than 90 nm in size and spherical in shape. This was confirmed with DLS which showed smaller particle size than those formed with 1:20 drug to PLGA-PEG ration. Further analysis showed zeta potential was negatively charge which could facilitate cellular uptake as reported previously. In addition, PDI value was less than 0.1 in both formulations indicating monodispersed and less broad in size distribution. The absorption peak of PLGA-PEG-TQ-Nps were at 255 nm. The 1:7 drug to polymer formulation was selected for further analysis where the entrapment efficiency was 79.9% and in vitro drug release showed a maximum release of TQ at 64% respectively. Cytotoxicity result showed IC50 of TQ-nanoparticle at 20.05 µM and free TQ was 8.25 µM. Conclusion: This study showed that nanoparticle synthesized with 1:7 drug to PLGA-PEG ratio and 2:1 PLGA-PEG to pluronic F68 were less than 100 nm and had spherical shape as confirmed with DLS. This could facilitate its transportation and absorption to reach its target. There was conserved TQ stability as exhibited by slow release of this volatile oil. Cytotoxicity effect was noted when resistant breast cancer cells were treated with these particles.

The Influence of Pluronic F68 and F127 Nanocarrier on Physicochemical Properties, In vitro Release, and Antiproliferative Activity of Thymoquinone Drug

BACKGROUND

This study reports on hydrophobic drug thymoquinone (TQ), an active compound found in the volatile oil of Nigella sativa that exhibits anticancer activities. Nanoformulation of this drug could potentially increase its bioavailability to specific target cells.

OBJECTIVE

The aim of this study was to formulate TQ into polymer micelle, Pluronic F127 (5.0 wt %) and Pluronic F68 (0.1 wt %), as a drug carrier to enhance its solubility and instability in aqueous media.

MATERIALS AND METHODS

Polymeric micelles encapsulated TQ were prepared by the microwave-assisted solvent evaporation technique. Fourier transform infrared spectroscopy and ultraviolet-visible spectrophotometer were utilized for qualitative confirmation of micelles encapsulation. The surface morphology and mean particle size of the prepared micelles were determined by using transmission electron microscopy (TEM). Cytotoxicity effect was studied using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay.

RESULTS

Dynamic laser light scattering (DLS) technique showed hydrodynamic size distribution of optimized micelles of 50 nm, which was in close agreement with the mean particle size obtained from TEM of about 51 nm. Drug release study showed the maximum percentage of TQ release at 61% after 72 h, while the entrapment efficiency of TQ obtained was 46% using PF127. The cytotoxic effect of PF127-encapsulated TQ was considerably higher compared to PF68-encapsulated TQ against MCF7 cells, as they exhibited IC₅₀value of 8 μM and 18 μM, respectively.

CONCLUSION

This study suggests higher molecular weight Pluronic polymer micelles (F127) with hydrophilic-hydrophobic segments which could be used as a suitable candidate for sustainable delivery of TQ. However, comprehensive studies should be carried out to establish the suitability of Pluronic F127 as a carrier for other drugs with similar challenges as TQ.

SUMMARY

There is a rising interest in integrating nanotechnology with medicine, creating a nanomedicine aiming for high efficiency and efficacy of disease diagnosis and treatment. In drug delivery, the term nanomedicine describes the nanometer-sized range (1-1000 nm) of a multi-component drug for disease treatments. As such, liposome-based nanoparticulate delivery vehicles have been approved by the Food and Drug Administration (FDA) for clinical applications. The main purpose of introducing nanoscale drug delivery is to improve the pharmacological and pharmacokinetic profiles of therapeutic molecules. Drug or therapeutic molecules can be either released through the cleavage of a covalent linkage between drug molecules and polymers (conjugation) or through the diffusion from a drug and polymer blended matrix (physical encapsulation). Polymers play an important role in the design of nanocarriers for therapeutic deliveries. In Asia, Nigella sativa seed oil has been used traditionally for its various medicinal benefits. One of its most potent compound which is thymoquinone has been intensively investigated for its anti-cancer effects in colorectal carcinoma, breast adenocarcinoma, osteosarcoma, ovarian carcinoma, myeloblastic leukemia, and pancreatic carcinoma. In addition, it is reported to show anti-inflammatory potential, antidiabetic, antihistaminic effects, as well as the ability to alleviate respiratory diseases, rheumatoid arthritis, multiple sclerosis, and Parkinson's disease. This study aims to formulate and characterize different pluronic-based thymoquinone nanocarrier and investigate its effect against breast cancer cells Abbreviations Used: ATR-IR: Attenuated Total Reflectance-Infrared Spectroscopy, CH₃CN: Acetonitrile, DLS: Dynamic Light Scattering, MTS: [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, NPs: Nanoparticles, PF127/TQ: Pluronic F127 encapsulated TQ, PF68/TQ: Pluronic F68 encapsulated TQ, PLGA: Poly-(D,L-lactide-co-glycolide), PVA: Poly-vinylalcohol, TQ: Thymoquinone, UV/VIS: Ultravioletvisible spectrophotometry.

Green synthesis of mesoporous anatase TiO2 nanoparticles and their photocatalytic activities

Mesoporous anatase TiO₂ nanoparticles are produced by employing a facile green chemistry approach at low temperature with soluble starch as the template in this work. The obtained TiO₂ photocatalyst is visible-light active with good photocatalytic activities.