Beauveria bassiana biogenic nanoparticles for the control of Noctuidae pests

BACKGROUND

Biogenic metallic and oxide metal nanoparticles have potential as alternatives for several current problems in agriculture, such as the control of caterpillars which cause huge losses in the production of important crops. In the present study, capped and uncapped silver, iron oxide and titanium dioxide nanoparticles were synthesized from the filtrate of Beauveria bassiana and evaluated in regard to physico-chemical characteristics, capping composition, cytotoxicity, genotoxicity and biological activity on Helicoverpa armigera and Spodoptera frugiperda caterpillars.

RESULTS

A difference in the physico-chemical parameters of the capped and uncapped nanoparticles was observed, with larger aggregation and lower stability of the uncapped. In regard to the study of the capping, the presence of functional groups of biomolecules as well as the activity of B. bassiana hydrolytic enzymes were observed. Cytotoxic effects on the tested cell lines were not observed and DNA damage levels increased with more intense effects of the uncapped nanoparticles. In regard to the biological activity against Noctuidae pests, the uncapped and capped iron oxide, and uncapped titanium dioxide nanoparticles occasioned higher mortality (76%, 60% and 51%, respectively) but no differences in LC50 were recorded. Moreover, sublethal effects were reported on Helicoverpa armigera whereas Spodoptera frugiperda showed low susceptibility to the nanoparticles.

CONCLUSION

The results demonstrate that biogenic metallic and oxide metal nanoparticles might show promising effects for the control of caterpillars which cause damage on important agricultural crops. Further investigations are necessary to understand the mechanisms of action and optimize the biological activity of these new nanomaterials. © 2023 Society of Chemical Industry.

Unveiling the cytotoxic and anti-proliferative potential of green-synthesized silver nanoparticles mediated by Colletotrichum gloeosporioides

Fungal endophytes are a putative source of bioactive metabolites that have found significant applications in nanomedicine due to their metabolic versatility. In the present study, an aqueous extract of the fungal endophyte, Colletotrichum gloeosporioides associated with a medicinal plant Oroxylum indicum, has been used for the fabrication of green silver nanoparticles (CgAgNPs) and further evaluated their cytotoxic and anti-proliferative activity. Bioanalytical techniques including UV-Vis spectral analysis revealed a sharp band at 435 nm and functional molecules from the aqueous extract involved in the synthesis of CgAgNPs were evidenced through FTIR. Further, the crystalline nature of CgAgNPs was determined through XRD analysis and microscopy techniques including AFM, TEM and FESEM demonstrated the spherical shape of CgAgNPs exhibiting a crystalline hexagonal lattice and the size was found to be in the range of 9-29 nm. The significant cytotoxic potential of CgAgNPs was observed against breast cancer cells, MDA-MB-231 and MCF-7 with IC50 values of 18.398 ± 0.376 and 38.587 ± 1.828 μg mL-1, respectively. The biochemical study revealed that the treatment of MDA-MB-231 and MCF-7 cells with CgAgNPs reduces glucose uptake, suppresses cell proliferation, and enhances LDH release, indicating reduced cell viability and progression. Moreover, our research revealed differential expression of genes associated with apoptosis, cell cycle inhibition and metastasis suppression, evidencing anti-proliferative activity of CgAgNPs. The main objective of the present study is to harness anti-breast cancer activity of novel biogenic nanoparticles synthesized using the aqueous extract of O. indicum associated C. gloeosporioides and study the underlying mechanistic pathway exerted by these mycogenic nanoparticles.

Nanotechnological interventions of the microbiome as a next-generation antimicrobial therapy

The rise of antimicrobial resistance (AMR) impacts public health due to the diminished potency of existing antibiotics. The microbiome plays an important role in the host's immune system activity and shows the history of exposure to antimicrobials and its manipulation in combating antimicrobial resistance. Advancements in gene technologies, DNA sequencing, and computational biology have emerged as powerful platforms to better understand the relationship between animals and microorganisms (MOs). The past few years have witnessed an increase in the use of nanotechnology, both in industry and in academia, as tools to tackle antimicrobial resistance. New strategies of microbiome manipulation have been developed, such as the use of prebiotics, probiotics, peptides, antibodies, an appropriate diet, phage therapy, and the use of various nanotechnological techniques. Owing to the research outcomes, targeted delivery of antimicrobials with some modifications with nanoparticles can lead to the destruction of resistant microbial cells. In addition, nanoparticles have been studied for their potential antimicrobial effects both in vitro and in vivo. In this review, we highlight key opportunistic areas for applying nanotechnologies with the aim of manipulating the microbiome for the treatment of antimicrobial resistance. Besides providing a detailed review on various nanomaterials, technologies, opportunities, technical needs, and potential approaches for the manipulation of the microbiome to address these challenges, we discuss future challenges and our perspective.

Evaluation of the efficacy of different concentrations of nano-capsules containing Talaromyces flavus with two forms of powder and suspension in reducing the incidence of cotton Verticillium wilt

Previous domestic and foreign studies have shown the significant effect of Talaromyces flavus on growth inhibition of some important plant pathogens including Verticillium dahliae, Fusarium oxysporum f. sp. lycopersici and Fusarium oxysporum f. sp. cucumerinum. In Iran, it is necessary to produce new formulations of this fungus based on modern technologies given the importance of attracting companies producing biological control agents and transferring the technical knowledge of mass production of formulations of these agents to them. In the present study, based on the method presented in the Pesticide Research Department of the Iranian Plant Protection Research Institute, two types of T. flavus formulations in the form of nano-capsules containing Talaromyces flavus with two forms of powder and suspension were prepared using nanotechnology. In the next step, during the greenhouse examination, the efficiency of each of these new formulations in concentrations of one to five per thousand for soil addition method and concentration of five per thousand for seed impregnation method (six treatments for each of the two new formulations) was compared with the registered formulation of Talaromin in two methods of seed impregnation and soil addition with healthy control and infected control to control cotton Verticillium wilt disease, in the form of a randomized complete block design with 16 treatments and 5 replications. After statistical analysis of the data obtained by Duncan's Multiple Range Test by MS TAT C software, the results showed that in terms of disease severity among treatments with the previous formulation (Talaromin) with each of the methods of soil addition and seed impregnation, there was no statistically significant difference between nano-suspension with each of the concentrations of one, four and five per thousand by the soil addition method and nano-powder with each of the concentrations of two and three per thousand by soil addition method, and the mentioned treatments were included in one statistical group in terms of disease severity with healthy control.

Fungi fabrication, characterization, and anticancer activity of silver nanoparticles using metals resistant Aspergillus niger

The purpose of this study was to assess the bio-fabrication possibilities of pre-isolated (from bauxite mine tailings) metal-tolerant Aspergillus niger biomass filtrate and the anticancer potential of synthesized silver nanoparticles (AgNPs) tested with a Human Cervical cancer cell line (HeLa cells: Henrietta Lacks cells). The nitrate reduction test demonstrated that A. niger has the ability to reduce nitrate, and filtrate derived from A. niger biomass efficiently fabricated AgNPs from AgNO₃, as demonstrated by a visible color change from pale greenish to brownish. The UV-visible spectroscopy analysis revealed an absorbance peak at 435 nm, which corresponded to the AgNPs. These AgNPs have been capped and stabilized with several functional groups related to various bioactive molecules such as aldehyde, benzene rings, aldehydic, amines, alcohols, and carbonyl stretch protein molecules. Fourier-Transform Infrared Spectroscopy (FTIR) analysis confirmed the capping and stabilizing chemical bonding pattern. Scanning Electron Microscopy (SEM) revealed that the synthesized AgNPs were spherical, with an average size of 21.38 nm. This bio-fabricated AgNPs has in-vitro anticancer potential when tested against the HeLa cell line due to its potential size and shape. At 100 g mL^-1 concentrations of this bio-fabricated AgNPs, the anticancer activity percentage was found to be 70.2%, and the IC₅₀ value was found to be 66.32 g m^-1. These findings demonstrated that the metal-tolerant A. niger cell filtrate could produce AgNPs with anticancer potential.

Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.

Functional Attributes of Myco-Synthesized Silver Nanoparticles from Endophytic Fungi: A New Implication in Biomedical Applications

To develop a benign nanomaterial from biogenic sources, we have attempted to formulate and fabricate silver nanoparticles synthesized from the culture filtrate of an endophytic fungus Penicillium oxalicum strain LA-1 (PoAgNPs). The synthesized PoAgNPs were exclusively characterized through UV-vis absorption spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), and Transmission Electron Microscopy (TEM) with energy dispersive X-ray spectroscopy (EDX). The synthesized nanoparticles showed strong absorbance around 430 nm with surface plasmon resonance (SPR) and exhibited a face-centered cubic crystalline nature in XRD analysis. Proteins presented in the culture filtrate acted as reducing, capping, and stabilization agents to form PoAgNPs. TEM analysis revealed the generation of polydispersed spherical PoAgNPs with an average size of 52.26 nm. The PoAgNPs showed excellent antibacterial activity against bacterial pathogens. The PoAgNPs induced a dose-dependent cytotoxic activity against human adenocarcinoma breast cancer cell lines (MDA-MB-231), and apoptotic morphological changes were observed by dual staining. Additionally, PoAgNPs demonstrated better larvicidal activity against the larvae of Culex quinquefasciatus. Moreover, the hemolytic test indicated that the as-synthesized PoAgNPs are a safe and biocompatible nanomaterial with versatile bio-applications.

An integrated approach to assess the sublethal effects of colloidal gold nanorods in tadpoles of Xenopus laevis

Gold nanorods (AuNR) have been explored for many applications, including innovative nanomedicines, which also might contribute to its increase in the environment, namely due to inadequate disposable of wastes into aquatic environments. Early-life stages of amphibians are usually aquatic and sensitive to chemical contamination. Accordingly, this study aimed to determine the sublethal effects of CTAB functionalized AuNR on Xenopus laevis tadpoles. As such, tadpoles were exposed to serial concentrations of AuNR for 72 h. A reduction in the rate of feeding (EC₅₀ = 4 μg.L^-1), snout to vent growth (EC₅₀ = 5 μg.L^-1) and weight gain (EC₅₀ = 6 μg.L^-1), was observed for AuNR-exposed tadpoles. Also, tadpoles actively avoided concentrations ≥ 4 μg.L^-1 of AuNR, after 12 h of exposure. At the biochemical level, AuNR caused impairments in antioxidant and nervous system related enzymes. Exposure to CTAB alone caused a high mortality. Results indicated that CTAB functionalized AuNR may induce several sublethal effects that may compromise the organism's fitness. Avoidance behavior (which corresponds to the disappearance of organisms, thus, similar to their death), observed at concentrations matching those inducing sublethal effects, suggest that it should be considered in the risk assessment for amphibians.

Synthesis and characterization of crustin capped titanium dioxide nanoparticles: Photocatalytic, antibacterial, antifungal and insecticidal activities

Current scenario of bio-nanotechnology, successfully fabrication of ultrafine titanium dioxide nanoparticles (TiO₂NPs) using various biological protein sources for the multipurpose targets. The present research report involves synthesis of TiO₂NPs using antimicrobial peptide (AMP) crustin (Cr). Crustin previously purified from the blue crab, Portunus pelagicus haemolymph, by blue Sepharose CL-6B matrix assisted affinity column chromatography. Synthesized Cr-TiO₂NPs was physico-chemically characterized by UV-Visible spectroscopy (UV-Visible), X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), High-resolution transmission electron microscopy (HR-TEM) and zeta potential examination. X-ray diffraction analysis for crystalline nature and phase identification of titanium dioxide nanoparticles was absorbed. Functional groups were found through FTIR ranges between 1620 and 1700 cm^-1. HR-TEM analysis showed that the synthesized Cr-TiO₂NPs tetragonal shape and sizes ranging from 10 to 50 nm. Finally, the surface charge of the Cr-TiO₂NPs was confirmed through zeta potential analysis. Furthermore, the characterized Cr-TiO₂NPs exhibited good biofilm inhibition against GPB - S. mutans (Gram Positive Bacteria- Streptococcus mutans), GNB - P. vulgaris (Gram Negative Bacteria- Proteus vulgaris) and fungal Candida albicans. Moreover, photocatalysis demonstrated that the Cr-TiO₂NPs was effectively explored the degradation of dyes. The results suggest that Cr-TiO₂NPs is an excellent bactericidal, fungicidal and photocatalytic agent that can be supportively used for biomedical and industrial applications.

Efficacy of green nanoparticles against cancerous and normal cell lines: a systematic review and meta-analysis

This study aimed to perform a systematic review and meta-analysis of papers discussing the efficacy of microbial synthesised metallic nanoparticles (MNPs) against cancerous and normal cell lines by exploiting Bayesian generalised linear (BGL) model. Data was systematically collected from published papers via Cochrane library, Web of Science, PubMed, Science Direct, ProQuest, Scopus, and Embase. Impressively, most of the studies were carried out on HeLa and A549 cancer cell lines. Specifically, a hefty 65.67% of studies employed bacteria to biofabricate MNPs. Significantly, BGL meta-analysis represented highly valuable information. Hence, based on adjusted analysis, the MNPs with the size of 25-50 nm were found to be far less cytotoxic than the MNPs with the size of ≤25 nm (OR = 0.233, P ˂ 0.05) against either cancerous or normal cell lines. Interestingly, it was found that the odds of cytotoxicity in cancerous cell lines were practically nine times more than normal cell lines, representing the substantially more cytotoxicity of MNPs in cancerous cell lines (OR = 9.004, P ˂ 0.001). Green MNPs mentioned here may be developed as novel anti-cancer agents, which could lead to a revolution in the treatment of cancer.

Mycosynthesis of bactericidal silver and polymorphic gold nanoparticles: physicochemical variation effects and mechanism

AIM

Extracellular synthesis of silver and gold nanoparticles using aqueous cell-free filtrate (CFF) of endophytic Chaetomium globosum and characterization of its bioactive proteins.

METHODS

Temperature and pH gradients were used to assess their effects on dimensions of NPs. NPs were tested in vivo for antibacterial activity. MALDI-TOF-MS/MS was used for characterization of CFF proteins.

RESULTS

Fungal CFF fabricated nanoparticles of various shape under varied physicochemical conditions. Silver nanoparticles showed significantly (p ≤ 0.5) enhanced antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae compared with AgNO₃. Two prominent CFF proteins showed homology with benzoate 4-monooxygenase cytochrome P450 and ubiquinol-cytochrome c reductase.

CONCLUSION

The study achieved controlled mycosynthesis of NPs and explains the hitherto poorly known mechanism of reduction, stabilization and antibacterial activity of nanoparticles.

A green chemistry approach for synthesizing thermostable antimicrobial peptide-coated gold nanoparticles immobilized in an alginate biohydrogel

Developing rapid, green, and cost effective approaches for synthesizing metal nanoparticles with biochemical and biomedical applications is currently a top priority.