Bio-fabricated zinc oxide and cry protein nanocomposites: Synthesis, characterization, potentiality against Zika, malaria and West Nile virus vector's larvae and their impact on non-target organisms.

The role of mosquito vectors in spreading disastrous diseases to living organisms, especially to humans is inevitable and undeniable. The impacts of the available chemical and synthetic insecticides on non-specific organisms as well as on nature are being the reason behind the search for target-specific, biocompatible and eco-friendly alternatives. The Madhuca longifolia seed extract and cry proteins from Bacillus thuringiensis-based nanocomposites (Cp-Ml-ZnO NCs) were produced to conquer the above-mentioned issues. The Cp-Ml-ZnO NCs (100 µg/mL) expressed better scavenging potentiality on 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radicals than Ml seed extract and Ml-ZnO NPs. The susceptibility of tested vector larvae to the Cp-Ml-ZnO NCs was Ae. aegypti ˃An. stephensi ˃ Cx. quinquefasciatus along with LC50-27.73, 34.81, and 42.54 µg/mL concentration. The target specificity and biocompatibility of Cp-Ml-ZnO NCs were authenticated by the results obtained by evaluating the efficacy on D. similis, A. salina, P. reticulata, G. affinis, and RBCs of goat blood. Thus the Cp-Ml-ZnO NCs could be adopted for the control of vector larvae.

Synthesis and characterization of cry protein coated zinc oxide nanocomposites and its assessment against bacterial biofilm and mosquito vectors.

Mosquitoes need to be eradicated as they can spread deadly diseases. Cry toxic proteins from Bacillus and zinc oxide nanoparticles also can tremendously control pest and bacterial pathogens. With this reference, the Ac-ZnO NPs was effectively synthesized using Acorus calamus rhizomes extract where after incorporated with bacterial cry toxic protein (Btp) to produce Btp-Ac-ZnO nanocomposites. The XRD and FTIR, disclose the crystalline form with an average size of 17.47 nm and the possible biomolecules of Btp-Ac-ZnO NCs. SEM and TEM make known the well agglomerated and cone shape of Btp-Ac-ZnO NCs. The NCs show concentration-dependent antioxidant activity. Btp-Ac-ZnO NCs drastically arrest the formation of biofilm by the pathogenic bacteria such as E. faecalis, S. aureus, P. aeruginosa, and P. vulgaris at 100 µg/mL. All the above, the Btp-Ac-ZnO NCs exhibits superior larvicidal activity against three mosquito vectors namely Ae. aegypti, An. stephensi and Cx. quinquefasciatus with LC50 values of 43.76, 39.60 and 37.13 µg/mL respectively. Besides, the biological enzymes are significantly reduced in the treated larvae than that of untreated one, which indicates the effect of Btp-Ac-ZnO NCs. Since, the Btp-Ac-ZnO NCs could be utilized against the pathogenic bacteria, and its biofilm structure, and also in the vector control sectors.

High synergistic antibacterial, antibiofilm, antidiabetic and antimetabolic activity of Withania somnifera leaf extract-assisted zinc oxide nanoparticle.

Nanotechnology is currently gaining immense attention to combat food borne bacteria, and biofilm. Diabetes is a common metabolic disease affecting majority of people. A better therapy relies on phytomediated nanoparticle synthesis. In this study, W. somnifera leaf extract-assisted ZnO NPs (Ws-ZnO NPs) was synthesized and characterized. From HR-TEM analysis, it has been found that the hexagonal wurtzite particle is 15.6 nm in size and - 12.14 mV of zeta potential. A greater antibacterial effect of Ws-ZnO NPs was noticed against E. faecalis and S. aureus at 100 µg mL-1. Also, the biofilm of E. faecalis and S. aureus was greatly inhibited at 100 µg mL-1 compared to E. coli and P. aeruginosa. The activity of α-amylase and α-glucosidase enzyme was inhibited at 100 µg mL-1 demonstrating its antidiabetic potential. The larval and pupal development was delayed at 25 µg mL-1 of Ws-ZnO NPs. A complete mortality (100%) was recorded at 25 µg mL-1. Ws-ZnO NPs showed least LC50 value (9.65 µg mL-1) compared to the uncoated ZnO NPs (38.8 µg mL-1) and leaf extract (13.06 µg mL-1). Therefore, it is concluded that Ws-ZnO NPs are promising to be used as effective antimicrobials, antidiabetic and insecticides to combat storage pests.

Synthesis of ZnO nanoparticles using insulin-rich leaf extract: Anti-diabetic, antibiofilm and anti-oxidant properties.

Here, we report the novel fabrication of ZnO nanoparticles using the Costus igneus leaf extract. Gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy to determine the bioactive components present in the plant extract. The synthesis of Ci-ZnO NPs (C. igneus- coated zinc oxide nanoparticles) was accomplished using a cost-effective and simple technique. Ci-ZnO NPs were specified using UV-visible spectroscopy, FTIR, XRD, and TEM. Ci-ZnO NPs was authenticated by UV-Vis and exhibited a peak at 365 nm. The XRD spectra proved the crystalline character of the Ci-ZnO NPs synthesized as hexagonal wurtzite. The FTIR spectrum illustrated the presence of possible functional groups present in Ci-ZnO NPs. The TEM micrograph showed evidence of the presence of a hexagonal organization with a size of 26.55 nm typical of Ci-ZnO NPs. The α-amylase and α-glucosidase inhibition assays demonstrated antidiabetic activity of Ci-ZnO NPs (74 % and 82 %, respectively), and the DPPH [2,2-diphenyl-1-picrylhydrazyl hydrate] assay demonstrated the antioxidant activity of the nanoparticles (75%) at a concentration of 100 µg/ml. The Ci-ZnO NPs exhibited promising antibacterial and biofilm inhibition activity against the pathogenic bacteria Streptococcus mutans, Lysinibacillus fusiformis, Proteus vulgaris, and Vibrio parahaemolyticus. Additionally, the Ci-ZnO NPs showed biocompatibility with mammalian RBCs with minimum hemolytic activity (0.633 % ±â€¯0.005 %) at a concentration of 200 µg/ml.