Comparative In Vitro Anticancer Study of Cisplatin Drug with Green Synthesized ZnO Nanoparticles on Cervical Squamous Carcinoma (SiHa) Cell Lines.

In this article, we aimed to develop a unique treatment approach to cure cervical cancer without harming healthy normal cells and overcome the limitations of currently available therapies/treatments. Recently, chemotherapeutics based on metal oxides have gained attention as a promising approach for treating cancer. Herein, ZnO nanoparticles were synthesized with the leaf extract of Azadirachta indica. These green synthesized ZnO nanoparticles were used for a cytotoxic study on the cervical squamous carcinoma cell line SiHa and murine macrophage cell line RAW 264.7. Moreover, a hemolytic assay was performed to check the biocompatibility of ZnO nanoparticles. The biosynthesized ZnO nanoparticles were labeled as L1, L2, L5, and L10 nanoparticles. Various assays like crystal violet, MTT assay, and AO/PI dual staining method were performed to assess the anticancer potential of ZnO. The concentration of ZnO nanoparticles was taken in the range of 100-250 µg/mL in the in vitro anticancer study on SiHa cancer cell lines. The findings of the MTT assay revealed that biosynthesized ZnO nanoparticles exhibited significant cytotoxicity against SiHa cancer cell lines dose-dependently at two incubation times (24 and 48 h). Also, a decrease in cell viability was observed with an increased concentration of ZnO. The IC50 values obtained were 141 µg/mL for L1, 132 µg/mL for L2, 127 µg/mL for L5, and 115 µg/mL for L10 nanoparticles. In addition, cisplatin drug (10 µg/mL) was also used to compare the anticancer activity with the biosynthesized L1, L2, L5, and L10 nanoparticles. The results of the crystal violet assay and AO/PI dual staining method revealed that morphological changes like cell shrinkage, poor cell adhesion, and induction of apoptosis occurred in the SiHa cancer cell lines. Furthermore, the stability of the ZnO nanoparticles at physiological pH has been assessed by recording the UV-visible spectrum at various pH values. Hence, the overall findings suggested that biosynthesized ZnO nanoparticles can be utilized for cervical squamous cancer treatment in addition to the current treatment strategies/techniques.

Coupling ZnO with CuO for efficient organic pollutant removal.

Fabrication of heterojunction semiconductors for the photodegradation of toxic organic dyes under sunlight exposure has earned significant recognition from researchers nowadays. On that account, we have synthesized and explored a comparative photodegradation study of ZnO/CuO nanocomposite with ZnO and CuO nanoparticles. ZnO and CuO nanoparticles have been synthesized by biosynthesis methods using Ficus benghalensis leaf extract. As-synthesized ZnO and CuO nanoparticles have been further utilized for the synthesis of ZnO/CuO nanocomposite by the mortar pestle crushing/milling method. Both biosynthesis methods and mortar pestle crushing/milling methods are simple, low-cost, and environmentally friendly. Structural, optical, and morphological analysis of all the synthesized nanomaterials have been done by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy. PXRD data reveal that synthesized ZnO nanoparticles are in the hexagonal wurtzite phase, CuO nanoparticles in the monoclinic phase, and ZnO/CuO nanocomposite in the hexagonal wurtzite as well as in monoclinic phase. FE-SEM and TEM images of ZnO/CuO nanocomposite reveal the nanorod-shaped morphology along with micro-sized and nano-sized flakes. The BET analysis shows the surface areas 18.128 m2/g for ZnO nanoparticles, 16.653 m2/g for CuO nanoparticles, and 19.580 m2/g for ZnO/CuO nanocomposite, respectively. The energy band gap values of ZnO/CuO nanocomposite are obtained 3.13 eV for ZnO and 2.76 eV for CuO, respectively. The photocatalytic behaviors of all the synthesized nanomaterials are examined against aqueous dye solutions of methylene blue (MB), rhodamine B (RhB), and methyl orange (MO) under sunlight irradiation. The results reveal that the photocatalytic degradation efficiency of ZnO/CuO nanocomposite has been found higher than with ZnO and CuO nanoparticles for all the dyes. Also, all the synthesized nanomaterials indicate higher photocatalytic degradation efficiency for methylene blue dye among all three dyes. The kinetics of photodegradation of all the dye solutions has also been investigated in the presence of ZnO, CuO, and ZnO/CuO photocatalysts separately. The results exhibit that rate constant values for all the dyes are higher with ZnO/CuO nanocomposite than with ZnO and CuO nanoparticles. ZnO/CuO nanocomposite demonstrates degradation efficiency for MB dye 99.13%, for RhB 80.21%, and for MO 67.22% after 180 min of sunlight exposure. ZnO/CuO nanocomposite and ZnO and CuO nanoparticles also show the best reusability and stability up to three cycles for photocatalytic degradation of MB dyes among all the dyes. Therefore, green synthesized ZnO/CuO nanocomposite could be used as an efficient photocatalyst for the degradation of various toxic dyes. The mineralization of different dyes using ZnO/CuO nanocomposite has been examined by FTIR analysis. Furthermore, the mineralization of MB dye has been done by total organic carbon (TOC) measurements.

A review on degradation of organic dyes by using metal oxide semiconductors.

The discharge of organic dye pollutants in natural water bodies has put forward a big challenge of providing clean water to a large part of the population. As the population is increasing with time, only underground water is not sufficient to complete the water requirements of everyone everywhere. Purification of wastewater and its reuse is the only way to fulfill the water needs. Nanotechnology has been used very efficiently for wastewater treatment via photocatalytic degradation of dye molecules. In the past few years, a lot of investigations have been done to enhance the photocatalytic activity of metal oxide semiconductors for water purification. In this review, we have discussed the different methods of synthesis of various metal oxide semiconductor nanoparticles, energy band gap, their role as efficient photocatalysts, radiations used for photocatalytic reactions, and their degradation efficiency to degrade the dye pollutants. We have also discussed the nanocomposites of metal oxide with graphene. These nanocomposites have been utilized as the efficient photocatalyst due to unique characteristics of graphene such as extended range of light absorption, separation of charges, and high capacity of adsorption of the dye pollutants.

Synthesis and characterization of NiO/Cr2O3 nanocomposite with effective sunlight driven photocatalytic degradation of organic dyes.

In this paper, nanocomposite NiO/Cr2O3 has been synthesized by a simple chemical reduction method to study its photocatalytic activity under sunlight irradiation. Various advanced analytical techniques including powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), elemental mapping, Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy have been utilized to characterize the synthesized NiO/Cr2O3 nanocomposite. SEM images show the sheet-shaped morphology of NiO/Cr2O3 nanocomposite. These sheets have a rough surface with nano to micro size cracks. These cracks play important role in the enhancement of photocatalytic activity by increasing surface active sites for the adsorption of dye molecules on the surface of the photocatalyst. The organic dyes crystal violet (CV) and methylene blue (MB) have been chosen to study the photocatalytic behavior of NiO/Cr2O3 nanocomposite under sunlight irradiation. The photocatalytic efficiency of NiO/Cr2O3 nanocomposite has been obtained 88.47% and 93.63% against crystal violet and methylene blue respectively. The results of the photocatalytic kinetics exhibit that degradation rate constant value for crystal violet dye is higher as compared to methylene blue dye. Obtained kinetic results indicate that synthesized nanocomposite acts as an efficient photocatalyst for the degradation of both crystal violet dye and methylene blue dye. NiO/Cr2O3 nanocomposite also exhibited reusability and stability for photocatalytic degradation of both organic dyes. Photoelectrochemical measurements as photocurrent, electrochemical impedance spectroscopy (EIS), and Mott-Schottky plot were also performed for synthesized NiO/Cr2O3 nanocomposite. Consequently, this synthesized NiO/Cr2O3 nanocomposite can be utilized for environmental remediation of harmful dyes.

Functionalized Hydrophilic Superparamagnetic Iron Oxide Nanoparticles for Magnetic Fluid Hyperthermia Application in Liver Cancer Treatment.

In this work, we report the synthesis of hydrophilic and surface-functionalized superparamagnetic iron oxide nanoparticles (SPIOs) to utilize them as nanomedicines for treating liver cancer via magnetic fluid hyperthermia (MFH)-based thermotherapy. For this purpose, initially, we have synthesized the SPIOs through co-precipitation/thermolysis methods, followed by in situ surface functionalization with short-chained molecules, such as 1,4-diaminobenzene (14DAB), 4-aminobenzoic acid (4ABA) and 3,4-diaminobenzoic acid (34DABA) and their combination with terephthalic acid (TA)/2-aminoterephthalic acid (ATA)/trimesic acid (TMA)/pyromellitic acid (PMA) molecules. The as-prepared SPIOs are investigated for their structure, morphology, water dispersibility, and magnetic properties. The heating efficacies of the SPIOs are studied in calorimetric MFH (C-MFH) with respect to their concentrations, surface coatings, dispersion medium, and applied alternating magnetic fields (AMFs). Although all of the as-prepared SPIOs have exhibited superparamagnetic behavior, only 14DAB-, 4ABA-, 34DABA-, and 4ABA-TA-coated SPIOs have shown higher magnetization values (Ms = 55-71 emu g-1) and good water dispersibility. In C-MFH studies, 34DABA-coated SPIO-based aqueous ferrofluid (AFF) has revealed faster thermal response to the applied AMF and reached therapeutic temperature even at the lowest concentration (0.5 mg mL-1) compared with 14DAB-, 4ABA-, and 4ABA-TA-coated SPIO-based AFFs. Moreover, 34DABA-coated SPIO-based AFF has exhibited high heating efficacies (i.e., specific absorption rate/intrinsic loss power values of 432.1 W gFe-1/5.2 nHm2 kg-1 at 0.5 mg mL-1), which could be mainly due to (i) enhanced π-π conjugation paths of surface-attached 34DABA coating molecules because of intrafunctional group attractions and (ii) improved anisotropy from the formation of clusters/linear chains of the SPIOs in ferrofluid suspensions, owing to interfunctional group attractions/interparticle interactions. Moreover, the 34DABA-coated SPIOs have demonstrated (i) very good cytocompatibility for 24/48 h incubation periods and (ii) higher killing efficiency of 61-88% (via MFH) in HepG2 liver cancer cells as compared to their treatment with only AMF/water-bath-based thermotherapy. In summary, the 34DABA-coated SPIOs are very promising heat-inducing agents for MFH-based thermotherapy and thus could be used as effective nanomedicines for cancer treatments.