Scaling-up strategies for controllable biosynthetic ZnO NPs using cell free-extract of endophytic Streptomyces albus: characterization, statistical optimization, and biomedical activities evaluation

Phytochemical fabrication of ZnO nanoparticles and their antibacterial and anti-biofilm activity

The synthesis of metal nanoparticles through bio-reduction is environmentally benign and devoid of impurities, which is very important for biological applications. This method aims to improve ZnO nanoparticle's antibacterial and anti-biofilm activity while reducing the amount of hazardous chemicals used in nanoparticle production. The assembly of zinc oxide nanoparticles (ZnO NPs) is presented via bio-reduction of an aqueous zinc nitrate solution using Echinochloacolona (E. colona) plant aqueous leaf extract comprising various phytochemical components such as phenols, flavonoids, proteins, and sugars. The synthesized nano ZnO NPs are characterized by UV-visible spectrophotometer (UV-vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (X-RD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental composition by energy-dispersive x-ray spectroscopy (EDX). The formation of biosynthesized ZnO nanoparticles was confirmed by the absorbance at 360-370 nm in the UV-vis spectrum. The average crystal size of the particles was found to be 15.8 nm, as calculated from XRD. SEM and TEM analysis of prepared ZnO NPs confirmed the spherical and hexagonal shaped nanoparticles. ZnO NPs showed antibacterial activity against Escherichia coli and Klebsiella pneumoniae with the largest zone of inhibition (ZOI) of 17 and 18 mm, respectively, from the disc diffusion method. Furthermore, ZnO NPs exhibited significant anti-biofilm activity in a dose-dependent manner against selected bacterial strains, thus suggesting that ZnO NPs can be deployed in the prevention of infectious diseases and also used in food preservation.

Green synthesis of trimetallic CuO/Ag/ZnO nanocomposite using Ziziphus spina-christi plant extract: characterization, statistically experimental designs, and antimicrobial assessment

In this study, Ziziphus spina christi leaves was used to synthesize a trimetallic CuO/Ag/ZnO nanocomposite by a simple and green method. Many characterizations e.g. FTIR, UV-vis DRS, SEM-EDX, TEM, XRD, zeta-size analysis, and DLS, were used to confirm green-synthesized trimetallic CuO/Ag/ZnO nanocomposite. The green, synthesized trimetallic CuO/Ag/ZnO nanocomposite exhibited a spherical dot-like structure, with an average particle size of around 7.11 ± 0.67 nm and a zeta potential of 21.5 mV. An extremely homogeneous distribution of signals, including O (79.25%), Cu (13.78%), Zn (4.42%), and Ag (2.55%), is evident on the surface of green-synthetic nanocomposite, according to EDX data. To the best of our knowledge, this is the first study to effectively use an industrially produced green trimetallic CuO/Ag/ZnO nanocomposite as a potent antimicrobial agent by employing different statistically experimental designs. The highest yield of green synthetic trimetallic CuO/Ag/ZnO nanocomposite was (1.65 mg/mL), which was enhanced by 1.85 and 5.7 times; respectively, by using the Taguchi approach in comparison to the Plackett-Burman strategy and basal condition. A variety of assays techniques were utilized to evaluate the antimicrobial capabilities of the green-synthesized trimetallic CuO/Ag/ZnO nanocomposite at a 200 µg/mL concentration against multidrug-resistant human pathogens. After a 36-h period, the tested 200 µg/mL of the green-synthetic trimetallic CuO/Ag/ZnO nanocomposite effectively reduced the planktonic viable counts of the studied bacteria, Escherichia coli and Staphylococcus aureus, which showed the highest percentage of biofilm reduction (98.06 ± 0.93 and 97.47 ± 0.65%; respectively).

Biogenic nanoparticles: pioneering a new era in breast cancer therapeutics-a comprehensive review

Breast cancer, a widespread malignancy affecting women globally, often arises from mutations in estrogen/progesterone receptors. Conventional treatments like surgery, radiotherapy, and chemotherapy face limitations such as low efficacy and adverse effects. However, nanotechnology offers promise with its unique attributes like targeted delivery and controlled drug release. Yet, challenges like poor size distribution and environmental concerns exist. Biogenic nanotechnology, using natural materials or living cells, is gaining traction for its safety and efficacy in cancer treatment. Biogenic nanoparticles synthesized from plant extracts offer a sustainable and eco-friendly approach, demonstrating significant toxicity against breast cancer cells while sparing healthy ones. They surpass traditional drugs, providing benefits like biocompatibility and targeted delivery. Thus, this current review summarizes the available knowledge on breast cancer (its types, stages, histopathology, symptoms, etiology and epidemiology) with the importance of using biogenic nanomaterials as a new and improved therapy. The novelty of this work lies in its comprehensive examination of the challenges and strategies for advancing the industrial utilization of biogenic metal and metal oxide NPs. Additionally; it underscores the potential of plant-mediated synthesis of biogenic NPs as effective therapies for breast cancer, detailing their mechanisms of action, advantages, and areas for further research.

Moringa oleifera seed methanol extract with consolidated antimicrobial, antioxidant, anti-inflammatory, and anticancer activities

The wide biological activity of the Moringa oleifera represents a potential opportunity for developing selective cancer treatment drugs. The bioactive phytochemicals in Moringa seed extract (MSE) indicated large numbers of phytochemicals (21 compounds) with dominant abundance for cycloisolongifolene, 8,9-dehydro-9-vinyl, and chamazulene accounting for 12.7% and 12.19% of the total detected compounds. The MSE showed a potent anticancer effect toward Caco-2, MDA, and HepG-2 cells with half-maximal inhibitory concentration (IC50) values of 9.15 ± 1.18, 4.85 ± 0.11, and 7.36 ± 0.22 µg/mL, respectively, with higher safety (≥31-folds) toward normal human cells (IC50 of 150.7 ± 11.11 µg/mL). It appears that MSE stimulates selective-dose-dependent cell shrinkage, and nuclear condensation in the tumor cells, which finally induces the apoptosis pathway to increase its anticancer action. Additionally, MSE showed a potent capability to stimulate cell cycle arrest in both main checkpoint phases (G0/G1 and G2/M) of cell population growth. The apoptotic death stimulation was confirmed through upregulation of tumor protein p53 (p53) and cyclin-dependent kinase inhibitor p21 (p21) expression by more than three- to sixfold and downregulation of B-cell lymphoma 2 expression (threefold) in MSE-treated cells compared to 5-fluorouracil (5-FU)-treated tumor cells. Furthermore, the MSE revealed strong anti-inflammatory activity with significant antioxidant activity by lowering nitric oxide levels and enhancing the superoxide dismutase activity. On the other hand, the MSE revealed broad-spectrum antibacterial activity in a dose-dependent manner against Staphylococcus aureus minimum inhibitory concentration (MIC of 1.25 mg/mL), followed by Salmonella typhimurium (MIC of 1.23 mg/mL), whereas Escherichia coli was the least sensitive to MSE activity (MIC of 22.5 mg/mL) with significant antibiofilm activity against sensitive pathogens.

Purification and characterization of the produced hyaluronidase by Brucella Intermedia MEFS for antioxidant and anticancer applications

Hyaluronidase (hyase) is an endoglycosidase enzyme that degrades hyaluronic acid (HA) and is mostly known to be found in the extracellular matrix of connective tissues. In the current study, eleven bacteria isolates and one actinomycete were isolated from a roaster comb and screened for hyase production. Seven isolates were positive for hyase, and the most potent isolate was selected based on the diameter of the transparent zone. Based on the morphological, physiological, and 16 S rRNA characteristics, the most potent isolate was identified as Brucella intermedia MEFS with accession number OR794010. The environmental conditions supporting the maximum production of hyase were optimized to be incubation at 30 ºC for 48 h and pH 7, which caused a 1.17-fold increase in hyase production with an activity of 84 U/mL. Hyase was purified using a standard protocol, including precipitation with ammonium sulphate, DEAE as ion exchange chromatography, and size exclusion chromatography using Sephacryle S100, with a specific activity of 9.3-fold compared with the crude enzyme. The results revealed that the molecular weight of hyase was 65 KDa, and the optimum conditions for hyase activity were at pH 7.0 and 37 °C for 30 min. The purified hyase showed potent anticancer activities against colon, lung, skin, and breast cancer cell lines with low toxicity against normal somatic cells. The cell viability of hyase-treated cancer cells was found to be in a dose dependent manner. Hyase also controlled the growth factor-induced cell cycle progression of breast cancer cells and caused relative changes in angiogenesis-related genes as well as suppressed many pro-inflammatory proteins in MDA cells compared with 5-fluorouracil, indicating the significant role of hyase as an anticancer agent. In addition, hyase recorded the highest DPPH scavenging activity of 65.49% and total antioxidant activity of 71.84% at a concentration of 200 µg/mL.

In vitro influence of PEG functionalized ZnO-CuO nanocomposites on bacterial growth

Polyethyleneglycol-coated biocompatible CuO-ZnO nanocomposites were fabricated hydrothermally varying Zn:Cu ratios as 1:1, 2:1, and 1:2, and their antibacterial activity was determined through the well diffusion method against the Gram-negative Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and the Gram-positive Staphylococcus aureus. The minimum inhibitory concentration and the minimum bactericidal concentration values of the synthesized samples were determined. Subsequently, the time synergy kill assay was performed to elucidate the nature of the overall inhibitory effect against the aforementioned bacterial species. The mean zone of inhibition values for all four samples are presented. The inhibitory effect increased with increasing concentration of the nanocomposite (20, 40 and 60 mg/ml) on all the bacterial species except for S. aureus. According to the MBC/MIC ratio, ZnO was found to be bacteriostatic for E. coli and P. aeruginosa, and bactericidal for S. aureus and K. pneumoniae. Zn:Cu 2:1 was bactericidal on all bacterial species. A bacteriostatic effect was observed on E. coli and P. aeruginosa in the presence of Zn:Cu 1:1 whereas, it showed a bactericidal effect on S. aureus and K. pneumoniae. Zn:Cu 1:2 exhibited a bacteriostatic effect on E. coli while a bactericidal effect was observed for E. coli, P. aeruginosa, and K. pneumoniae. The metal oxide nanocomposites were found to be more sensitive towards the Gram-positive strain than the Gram-negative strains. Further, all the nanocomposites possess anti-oxidant activity as shown by the DPPH assay.

Large-scale production of myco-fabricated ZnO/MnO nanocomposite using endophytic Colonstachys rosea with its antimicrobial efficacy against human pathogens

In this study, a ZnO/MnO nanocomposite was myco-fabricated using the isolated endophytic Clonostachys rosea strain EG99 as the nano-factory. The extract of strain EG99, a reducing/capping agent, was successfully titrated with equal quantities of Zn(NO3)2·6H2O and Mn(NO3)2·6H2O (precursors) in a single step to fabricate the rod-shaped ZnO/MnO nanocomposite of size 6.22 nm. The ZnO/MnO nanocomposite was myco-fabricated in 20 min, and the results were validated at 350 and 400 nm using UV-Vis spectroscopy. In a 7-L bioreactor, an industrial biotechnological approach was used to scale up the biomass of this strain, EG99, and the yield of the myco-fabricated ZnO/MnO nanocomposite. A controlled fed-batch fermentation system with a specific nitrogen/carbon ratio and an identical feeding schedule was used in this production process. Higher yields were obtained by adopting a controlled fed-batch fermentation approach in a 7-L bioreactor with a regular feeding schedule using a nitrogen/carbon ratio of 1:200. Overall, the fed-batch produced 89.2 g/l of biomass at its maximum, 2.44 times more than the batch's 36.51 g/l output. Furthermore, the fed-batch's maximum ZnO/MnO nanocomposite yield was 79.81 g/l, a noteworthy 14.5-fold increase over the batch's yield of 5.52 g/l. Finally, we designed an innovative approach to manage the growth of the endophytic strain EG99 using a controlled fed-batch fermentation mode, supporting the rapid, cheap and eco-friendly myco-fabrication of ZnO/MnO nanocomposite. At a dose of 210 µg/ml, the tested myco-fabricated ZnO/MnO nanocomposite exhibited the maximum antibacterial activity against Staphylococcus aureus (98.31 ± 0.8%), Escherichia coli (96.70 ± 3.29%), and Candida albicans (95.72 ± 0.95%). At the same dose, Staphylococcus aureus biofilm was eradicated in 48 h; however, Escherichia coli and Candida albicans biofilms needed 72 and 96 h, respectively. Our myco-fabricated ZnO/MnO nanocomposite showed strong and highly selective antagonistic effects against a variety of multidrug-resistant human pathogens. Therefore, in upcoming generations of antibiotics, it might be employed as a nano-antibiotic.

Bioinspired fabrication of zinc hydroxide-based nanostructure from lignocellulosic biomass Litchi chinensis leaves and its efficacy evaluation on antibacterial, antioxidant, and anticancer activity

Zinc-based nanostructures are known for their numerous potential biomedical applications. In this context, the biosynthesis of nanostructures using plant extracts has become a more sustainable and promising alternative to effectively replace conventional chemical methods while avoiding their toxic impact. In this study, following a low-temperature calcination process, a green synthesis of Zn-hydroxide-based nanostructure has been performed using an aqueous extract derived from the leaves of Litchi chinensis, which is employed as a lignocellulose waste biomass known to possess a variety of phytocompounds. The biogenic preparation of Zn-hydroxide based nanostructures is enabled by bioactive compounds present in the leaf extract, which act as reducing and capping agents. In order to evaluate its physicochemical characteristics, the produced Zn-hydroxide-based nanostructure has been subjected to several characterization techniques. Further, the multifunctional properties of the prepared Zn-hydroxide-based nanostructure have been evaluated for antioxidant, antimicrobial, and anticancer activity. The prepared nanostructure showed antibacterial efficacy against Bacillus subtilis and demonstrated its anti-biofilm activity as evaluated through the Congo red method. In addition, the antioxidant activity of the prepared nanostructure has been found to be dose-dependent, wherein 91.52 % scavenging activity could be recorded at 200 μg/ml, with an IC50 value of 45.22 μg/ml, indicating the prepared nanostructure has a high radical scavenging activity. Besides, the in vitro cytotoxicity investigation against HepG2 cell lines explored that the as-prepared nanostructure exhibited a higher cytotoxic effect and 73.21 % cell inhibition could be noticed at 25.6 μg/ml with an IC50 of 2.58 μg/ml. On the contrary, it was found to be significantly lower in the case of HEK-293 cell lines, wherein ~47.64 % inhibition could be noticed at the same concentration. These findings might be further extended to develop unique biologically derived nanostructures that can be extensively evaluated for various biomedical purposes.