Light Tailoring: Impact of UV-C Irradiation on Biosynthesis, Physiognomies, and Clinical Activities of Morus macroura-Mediated Monometallic (Ag and ZnO) and Bimetallic (Ag-ZnO) Nanoparticles

Differential Impact of Zinc Salt Precursors on Physiognomies, Anticancerous, and Antibacterial Activities of Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnONPs) are enormously popular semi-conductor metal oxides with diverse applications in every field of science. Many physical and chemical methods applied for the synthesis of ZnONPs are being rejected due to their environmental hazards. Therefore, ZnONPs synthesized from plant extracts are steered as eco-friendly showing more biocompatibility and biodegradability. Additionally, various synthesis conditions such as the type of precursor salt also play a role in influencing the physicochemical and biological properties of ZnONPs. In this study, green synthesis of ZnONPs from Acacia nilotica was carried out using zinc acetate (ZA-AN-ZNPs), zinc nitrate (ZN-AN-ZNPs), and zinc sulfate (ZS-AN-ZNPs) precursor salts. Surprisingly, characterization of ZnONPs using UV-visible spectroscopy, TEM, XRD, and EDX revealed the important role precursor salts played in influencing the size and shape of ZnONPs, i.e., 20-23 nm spherical (ZA-AN-ZNPs), 55-59 nm triangular (ZN-AN-ZNPs), and 94-97 nm nano-flowers (ZS-AN-ZNPs). FTIR analysis showed the involvement of alkaloids, alcohols, carboxylic acid, and phenolic compounds present in Acacia nilotica extract during the synthesis process. Since different precursor salts showed different morphology of ZnONPs, their biological activities were also variable. ZN-AN-ZNPs showed the highest cytotoxicity towards HepG2 cells with the lowest cell viability (28.92 ± 0.99%), highest ROS/RNS production (3425.3 ± 184.58 relative DHR123 fluorescence), and loss of mitochondrial membrane potential (1645.2 ± 32.12 relative fluorescence unit) as well as induced significant caspase-3 gene expression. In addition to this, studying the zone of inhibitions and minimum bactericidal and inhibitory concentrations of ZnONPs showed their exceptional potential as antibacterial agents. At MIC as low as 8 µg/mL, ZA-AN-ZNPs and ZN-AN-ZNPs exhibited significant bactericidal activities against human pathogens Klebsiella pneumoniae and Listeria monocytogenes, respectively. Furthermore, alkaline phosphatase, DNA/RNA leakage, and phosphate ion leakage studies revealed that a damage to the bacterial cell membrane and cell wall is involved in mediating the antibacterial effects of ZnONPs.

Anticancer Phytochemical-Based Nanoformulations: Therapeutic Intervention in Cancer Cell Lines

Phytochemicals have the potential to treat resistant cancer. They are delivered to the target site via nano-based carriers. Promising results are seen in preclinical and in vitro models, as phytochemical-based nanoformulations have improved cell cytotoxicity compared to single agents. They can synergistically inhibit cancer cell growth through p53 apoptosis in MCF-7 breast cancer cell lines. Moreover, synergic viability in reproducible glioma models at half inhibitory concentrations has been shown. Through caspase activation, phytochemical-based nanoformulations also increase cell death in 4T1 breast cancer cell lines. They have shown improved cytotoxicity at half inhibitory concentrations compared to single-agent drugs in cervical cancer. In terms of colorectal cancer, they have the potential to arrest cells in the S phase of the cell cycle and synergistically inhibit cell proliferation. In squamous cell carcinoma of the tongue, they inhibit protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathways. This review reports on developments in the therapeutic management of various cancers using phytochemical-based nanoformulations, which have shown potential benefits in the clinical management of cancer patients, halting/slowing the progression of the disease and ameliorating chemotherapy-induced toxicities.

Characterization and Biological Studies of Synthesized Titanium Dioxide Nanoparticles from Leaf Extract of Juniperus phoenicea (L.) Growing in Taif Region, Saudi Arabia

Green synthesis of metal nanoparticles in nanosized form has acquired great interest in the area of nanomedicine as an environmentally friendly and cost-effective alternative compared to other chemical and physical methods. This study deals with the eco-friendly green synthesis of titanium dioxide nanoparticles (TiO2 NPs) utilizing Juniperus phoenicea leaf extract and their characterization. The biosynthesis of TiO2 NPs was completed in 3 h and confirmed by UV-Vis spectroscopy, a strong band at 205.4 nm distinctly revealed the formation of NPs. Transmissions electron microscopy (TEM) analysis showed the synthesized TiO2 NPs are spherical in shape, with a diameter in a range of 10–30 nm. The XRD major peak at 27.1° congruent with the (110) lattice plane of tetragonal rutile TiO2 phase. Dynamic light scattering (DLS) analysis revealed synthesized TiO2 NPs average particle size (hydrodynamic diameter) of (74.8 ± 0.649) nm. Fourier transmission infrared (FTIR) revealed the bioactive components present in the leaf extract, which act as reducing and capping agents. The antimicrobial efficacy of synthesized TiO2NPs against, Staphylococcus aureus, and Bacillus subtilis (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), Yeast strain (Saccharomyces cerevisiae) and fungi (Aspergillus niger, and Penicillium digitatum) assayed by a disc diffusion method. TiO2NPs inhibited all tested strains by mean inhibition zone (MIZ), which ranged from the lowest 15.7 ± 0.45 mm against K. pneumoniae to the highest 30.3 ± 0.25 against Aspergillus niger. The lowest minimum inhibitory concentration (MIC) and bactericidal (MBC) values were 20 μL/mL and 40 μL/mL of TiO2NPs were observed against Asp. niger. Moreover, it showed significant inhibitory activity against human ovarian adenocarcinoma cells with IC50 = 50.13 ± 1.65 µg/mL. The findings concluded that biosynthesized TiO2 NPs using Juniperus phoenicea leaf extract can be used in medicine as curative agents according to their in vitro antibacterial, antifungal, and cytotoxic activities.

Green synthesis of biocompatible core-shell (Au-Ag) and hybrid (Au-ZnO and Ag-ZnO) bimetallic nanoparticles and evaluation of their potential antibacterial, antidiabetic, antiglycation and anticancer activities

The fabrication of bimetallic nanoparticles (BNPs) using plant extracts is applauded since it is an environmentally and biologically safe method. In this research, Manilkara zapota leaf extract was utilized to bioreduce metal ions for the production of therapeutically important core-shell Au-Ag and hybrid (Au-ZnO and Ag-ZnO) BNPs. The phytochemical profiling of the leaf extract in terms of total phenolic and flavonoid content is attributed to its high free radical scavenging activity. FTIR data also supported the involvement of these phytochemicals (polyphenols, flavonoids, aromatic compounds and alkynes) in the synthesis of BNPs. Whereas, TEM and XRD showed the formation of small sized (16.57 nm) spherical shaped core-shell Au-Ag BNPs and ZnO nano-needles with spherical AuNPs (48.32 nm) and ZnO nano-rods with spherical AgNP (19.64 nm) hybrid BNPs. The biological activities of BNPs reinforced the fact that they show enhanced therapeutic efficacy as compared to their monometallic components. All BNPs showed comparable antibacterial activities as compared to standard tetracycline discs. While small sized Au-Ag BNPs were most effective in killing human hepato-cellular carcinoma cells (HepG2) in terms of lowest cell viability, highest intracellular ROS/RNS production, loss of mitochondrial membrane potential, induction of caspase-3 gene expression and enhanced caspase-3/7 activity. BNPs also effectively inhibited advanced glycation end products and carbohydrate digesting enzymes which can be used as a nano-medicine for aging and diabetes. The most important finding was the permissible biocompatibility of these BNPs towards brine shrimp larvae and human RBCs, which suggests their environmental and biological safety. This research study gives us insight into the promise of using a green route to synthesize commercially important BNPs with enhanced therapeutic efficacy as compared to conventional treatment options.

Light-emitting diode (LED)-directed green synthesis of silver nanoparticles and evaluation of their multifaceted clinical and biological activities

The trend of using plant extracts for the synthesis of nanoparticles has increased in recent years due to environmental safety, low cost, simplicity and sustainability of the green route. Moreover, the morphology of NPs can be fine-tuned by applying abiotic factors such as LEDs, which enhance the bio-reduction of the precursor salt and excite phytochemicals during their green synthesis. Considering this, in present study, the green synthesis of AgNPs was carried out using Dalbergia sissoo leaf extract under the illumination of red, green, blue, yellow and white LEDs. The phytochemical profile of the leaf extract in terms of total phenolic and flavonoid content was responsible for the effective synthesis of AgNPs, where alcohols and phenols were mainly involved in the capping and bio-reduction of the NPs. Moreover, the XRD data showed the face center cubic crystalline nature of the AgNPs with the interesting finding that the LEDs helped to reduce the size of the AgNPs significantly. Among the samples, Y-DS-AgNPs (34.63 nm) were the smallest in size, with the control having a size of 87.35 nm. The LEDs not only reduced the size of the AgNPs but also resulted in the synthesis of non-agglomerated AgNPs with different shapes including spherical, triangular, and hexagonal compared to the mixed-shape control AgNPs, as shown by the SEM analysis. These LED-directed AgNPs showed extraordinary therapeutic potential especially B-DS-AgNPs, which exhibited the highest anti-oxidant, anti-glycation and anti-bacterial activities. Alternatively, Y-DS-AgNPs were the most cytotoxic towards HepG2 cells, inducing intracellular ROS/RNS production, accompanied by a disruption in the mitochondrial membrane potential, caspase-3 gene activation and induction of caspase-3/7 activity. Lastly, AgNPs showed mild toxicity towards brine shrimp and moderately hemolyzed hRBCs, showing their biosafe nature. Here, we conclude that external factors such as LEDs are effective in controlling the morphology of AgNPs, which further enhanced their therapeutic efficacy.

Plant-Based Green Synthesis of Nanoparticles: Production, Characterization and Applications

Nanotechnology is a fast-expanding and multidisciplinary field with many applications in science and technology [...].