Isolation and characterization of a novel thermophile; Bacillus haynesii, applied for the green synthesis of ZnO nanoparticles

Eco-friendly zinc oxide nanoparticle biosynthesis powered by probiotic bacteria

The rapid advancement of nanotechnology, particularly in the realm of pharmaceutical sciences, has significantly transformed the potential for treating life-threatening diseases. A pivotal aspect of this evolution is the emergence of "green nanotechnology," which emphasizes the environmentally sustainable synthesis of raw materials through biological processes. This review focuses on the biological synthesis and application of zinc oxide (ZnO) nanoparticles (NPs) from probiotic bacteria, particularly those sourced from wastewater. Microorganisms from wastewater tolerate harmful elements and enzymatically convert toxic heavy metals into eco-friendly materials. These probiotic bacteria are instrumental in the synthesis of ZnO NPs and exhibit remarkable antimicrobial properties with diverse industrial applications. As the challenge of drug-resistant pathogens escalates, innovative strategies for combating microbial infections are essential. This review explores the intersection of nanotechnology, microbiology, and antibacterial resistance, highlighting the importance of selecting suitable probiotic bacteria for synthesizing ZnO NPs with potent antibacterial activity. Additionally, the review addresses the biofunctionalization of NPs and their applications in environmental remediation and therapeutic innovations, including wound healing, antibacterial, and anticancer treatments. Eco-friendly NP synthesis relies on the identification of these suitable microbial "nano-factories." Targeting probiotic bacteria from wastewater can uncover new microbial NP synthesis capabilities, advancing environmentally friendly NP production methods. KEY POINTS: • Innovative strategies are needed to combat drug-resistant pathogens like MRSA. • Wastewater-derived probiotic bacteria are an eco-friendly method for ZnO synthesis. • ZnO NPs show significant antimicrobial activity against various pathogens.

Green Synthesis of Zinc Oxide Nanoparticles: Preparation, Characterization, and Biomedical Applications - A Review

Over the last decade, biomedical nanomaterials have garnered significant attention due to their remarkable biological properties and diverse applications in biomedicine. Metal oxide nanoparticles (NPs) are particularly notable for their wide range of medicinal uses, including antibacterial, anticancer, biosensing, cell imaging, and drug/gene delivery. Among these, zinc oxide (ZnO) NPs stand out for their versatility and effectiveness. Recently, ZnO NPs have become a primary material in various sectors, such as pharmaceutical, cosmetic, antimicrobials, construction, textile, and automotive industries. ZnO NPs can generate reactive oxygen species and induce cellular apoptosis, thus underpinning their potent anticancer and antibacterial properties. To meet the growing demand, numerous synthetic approaches have been developed to produce ZnO NPs. However, traditional manufacturing processes often involve significant economic and environmental costs, prompting a search for more sustainable alternatives. Intriguingly, biological synthesis methods utilizing plants, plant extracts, or microorganisms have emerged as ideal for producing ZnO NPs. These green production techniques offer numerous medicinal, economic, environmental, and health benefits. This review highlights the latest advancements in the green synthesis of ZnO NPs and their biomedical applications, showcasing their potential to revolutionize the field with eco-friendly and cost-effective solutions.

Biomimetic synthesis of nanoparticles: A comprehensive review on green synthesis of nanoparticles with a focus on Prosopis farcta plant extracts and biomedical applications

The synthesis of nanoparticles (NPs) using environmentally friendly methods has garnered significant attention in response to concerns about the environmental impact of various nanomaterial manufacturing techniques. To address this issue, natural resources like extracts from plants, fungi, and bacteria are employed as a green alternative for nanoparticle synthesis. Plant extracts, which contain active components such as terpenoids, alkaloids, phenols, tannins, and vitamins, operate as coating and reducing agents. Bacteria and fungi, on the other hand, rely on internal enzymes, sugar molecules, membrane proteins, nicotinamide adenine dinucleotide (NADH), and nicotinamide adenine dinucleotide phosphate (NADPH) dependent enzymes to play critical roles as reducing agents. This review collects recent advancements in biomimetic methods for nanoparticle synthesis, critically discussing the preparation approaches, the type of particles obtained, and their envisaged applications. A specific focus is given on using Prosopis fractal plant extracts to synthesize nanoparticles tailored for biomedical applications. The applications of this plant and its role in the biomimetic manufacturing of nanoparticles have not been reported yet, making this review a pioneering and valuable contribution to the field.

Green synthesis of zinc oxide nanoparticles using novel bacterium strain (Bacillus subtilis NH1-8) and their in vitro antibacterial and antibiofilm activities against Salmonellatyphimurium

Zinc oxide nanoparticles (ZnO NPs) are used in a range of applications, including food packaging, preservation, and storage. In the current investigation, extracellular green synthesis of ZnO NPs through an simple, eco-friendly, and rapid approach using a novel bacterial strain (Bacillus subtilis NH1-8) was studied. To assess the morphological, optical, and structural properties of ZnO NPs, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, and X-ray diffraction (XRD) techniques were carried out. In addition, disk diffusion, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC) methods were performed to determine the antibacterial activity of ZnO NPs. The average size of biosynthesized ZnO NPs was 39 nm, exhibiting semi-spherical, which was confirmed by TEM analyses. The UV-vis spectroscopy exhibited the absorption peak at 200-800nm. The ZnO NPs have shown effective antimicrobial and antibiofilm activities against S. typhimurium. Thus, biosynthesized ZnO NPs could be exploited as a breakthrough technology in the surface coating of food containers and cans to minimize contamination by S. typhimurium.

Zinc oxide nanoparticles prepared through microbial mediated synthesis for therapeutic applications: a possible alternative for plants

Zinc oxide nanoparticles (ZnO-NPs) synthesized through biogenic methods have gained significant attention due to their unique properties and potential applications in various biological fields. Unlike chemical and physical approaches that may lead to environmental pollution, biogenic synthesis offers a greener alternative, minimizing hazardous environmental impacts. During biogenic synthesis, metabolites present in the biotic sources (like plants and microbes) serve as bio-reductants and bio-stabilizers. Among the biotic sources, microbes have emerged as a promising option for ZnO-NPs synthesis due to their numerous advantages, such as being environmentally friendly, non-toxic, biodegradable, and biocompatible. Various microbes like bacteria, actinomycetes, fungi, and yeast can be employed to synthesize ZnO-NPs. The synthesis can occur either intracellularly, within the microbial cells, or extracellularly, using proteins, enzymes, and other biomolecules secreted by the microbes. The main key advantage of biogenic synthesis is manipulating the reaction conditions to optimize the preferred shape and size of the ZnO-NPs. This control over the synthesis process allows tailoring the NPs for specific applications in various fields, including medicine, agriculture, environmental remediation, and more. Some potential applications include drug delivery systems, antibacterial agents, bioimaging, biosensors, and nano-fertilizers for improved crop growth. While the green synthesis of ZnO-NPs through microbes offers numerous benefits, it is essential to assess their toxicological effects, a critical aspect that requires thorough investigation to ensure their safe use in various applications. Overall, the presented review highlights the mechanism of biogenic synthesis of ZnO-NPs using microbes and their exploration of potential applications while emphasizing the importance of studying their toxicological effects to ensure a viable and environmentally friendly green strategy.

Nano-sized warriors: zinc chromium vanadate nanoparticles as a dual solution for eradicating waterborne enterobacteriaceae and fighting cancer

The revolution of biomedical applications has opened new avenues for nanotechnology. Zinc Chromium vanadate nanoparticles (VCrZnO4 NPs) have emerged as an up-and-coming candidate, with their exceptional physical and chemical properties setting them apart. In this study, a one-pot solvothermal method was employed to synthesize VCrZnO4 NPs, followed by a comprehensive structural and morphological analysis using a variety of techniques, including X-Ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Energy-dispersive X-ray, and X-ray photoelectron spectroscopy. These techniques confirmed the crystallinity of the NPs. The VCrZnO4 NPs were tested for their antibacterial activity against primary contaminants such as Enterobacteriaceae, including Shigella flexneri, Salmonella cholerasis, and Escherichia coli, commonly found in hospital settings, using the broth dilution technique. The results indicated a stronger antibacterial activity of VCrZnO4 NPs against Shigella and Salmonella than E. coli. Electron microscopy showed that the NPs caused severe damage to the bacterial cell wall and membrane, leading to cell death. In addition, the study evaluated the anticancer activities of the metal complexes in vitro using colorectal cancer cells (HCT-116) and cervical cancer cells (HELA), along with non-cancer cells and human embryonic kidney cells (HEK-293). A vanadium complex demonstrated efficient anticancer effects with half-inhibitory concentrations (IC₅₀) of 38.50+3.50 g/mL for HCT-116 cells and 42.25+4.15 g/mL for HELA cells. This study highlights the potential of Zinc Chromium vanadate nanoparticles as promising candidates for antibacterial and anticancer applications. Various advanced characterization techniques were used to analyze the properties of nanomaterials, which may help develop more effective and safer antibacterial and anticancer agents in the future.

Metal Nanoparticles to Combat Candida albicans Infections: An Update

Candidiasis is an opportunistic mycosis with high annual incidence worldwide. In these infections, Candida albicans is the chief pathogen owing to its multiple virulence factors. C. albicans infections are usually treated with azoles, polyenes and echinocandins. However, these antifungals may have limitations regarding toxicity, relapse of infections, high cost, and emergence of antifungal resistance. Thus, the development of nanocarrier systems, such as metal nanoparticles, has been widely investigated. Metal nanoparticles are particulate dispersions or solid particles 10-100 nm in size, with unique physical and chemical properties that make them useful in biomedical applications. In this review, we focus on the activity of silver, gold, and iron nanoparticles against C. albicans. We discuss the use of metal nanoparticles as delivery vehicles for antifungal drugs or natural compounds to increase their biocompatibility and effectiveness. Promisingly, most of these nanoparticles exhibit potential antifungal activity through multi-target mechanisms in C. albicans cells and biofilms, which can minimize the emergence of antifungal resistance. The cytotoxicity of metal nanoparticles is a concern, and adjustments in synthesis approaches or coating techniques have been addressed to overcome these limitations, with great emphasis on green synthesis.

Green synthesis of zinc oxide nanoparticles using Bacillus subtilis ZBP4 and their antibacterial potential against foodborne pathogens

In this study, extracellular biosynthesis of zinc oxide nanoparticles (ZnO NPs) by using the supernatant of Bacillus subtilis ZBP4 after cultivation in nutrient broth at 33 °C for 24 h was investigated. Zinc sulfate heptahydrate was used as the precursor, and the reactions were performed at 33 °C for 72 h. The effects of pH 5-9 and precursor concentration (2-10 mM) were determined and the optima were found to be pH 7.5 and 8 mM ZnSO₄·7H₂O, respectively. The nanoparticles were characterized by UV-VIS spectroscopy, FESEM, TEM, EDS, XRD, FTIR and zeta potential measurement. ZnO NPs appeared to be irregular spherical structures with a size range of 22-59 nm, as confirmed by FESEM and TEM. Energy-dispersive spectroscopy analysis validated the formation of ZnO NPs. X-ray diffraction analysis revealed the crystalline structure of the ZnO NPs, and they were determined to have a zeta potential of -19.0 ± 4.3 mV and a bandgap of 3.36 eV. Antibacterial activity experiments showed that ZnO NPs are effective against a broad spectrum of Gram-positive and Gram-negative food pathogens. This study provides evidence for a safe and effective method for synthesizing ZnO NPs and demonstrates their effectiveness against pathogenic bacteria.

Endophytic microbiome of Boehmeria nivea and their antagonism against latent fungal pathogens in plants

BACKGROUND

Pathogenic microbes still become obstacles that can reduce the quality of plant growth, including ramie (Boehmeria nivea) plants. The study identified the microbiome and antagonistic interaction of the endophytic community from the B. nivea is necessary to improve the production of the ramie plant, especially ramie stem organs for fiber materials.  RESULTS: Twenty isolates of endophytic microorganisms were obtained from the roots, stems, leaves, and flowers. They were identified using the Internal Transcribed Spacer (ITS) region of ribosomal (rDNA), and its morphotypes obtained 20 isolates, with a composition of 9 species of bacteria and 11 species of fungi. Besides that, the disease observations on ramie stems showed that four species of pathogenic fungi were identified as Fusarium solani isolate 3,248,941, Fusarium solani isolates colpat-359, Fusarium oxysporum isolate N-61-2, Clonostachys rosea strain B3042. The endophytic microorganism of ramie ability was tested to determine their potential to inhibit the growth of the pathogenic fungi based on the in-vivo antagonist test. The isolated bacteria were only able to inhibit the growth of F. solani, with the highest percentage of 54-55%. Three species of endophytic fungi, including Cladosporium tennissimum, Fusarium falciforme, and Penicillium citrinum, showed the best inhibition against the fungal pathogen Fusarium solani with the highest inhibitory presentation of 91-95%. Inhibitory interaction between the endophytic microbes and the ramie pathogens indicated the type of antibiosis, competition, and parasitism.  CONCLUSION: The results of this study succeeded in showing the potential antifungal by endophytic fungi from ramie against the pathogens of the plant itself. P. citrinum isolate MEBP0017 showed the highest inhibition against all the pathogens of the ramie.

In Vitro Antimicrobial and Anticancer Peculiarities of Ytterbium and Cerium Co-Doped Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnO NPs) are a promising platform for their use in biomedical research, especially given their anticancer and antimicrobial activities. This work presents the synthesis of ZnO NPs doped with different amounts of rare-earth ions of ytterbium (Yb) and cerium (Ce) and the assessment of their anticancer and antimicrobial activities. The structural investigations indicated a hexagonal wurtzite structure for all prepared NPs. The particle size was reduced by raising the amount of Ce and Yb in ZnO. The anticancer capabilities of the samples were examined by the cell viability MTT assay. Post 48-h treatment showed a reduction in the cancer cell viability, which was x = 0.00 (68%), x = 0.01 (58.70%), x = 0.03 (80.94%) and x = 0.05 (64.91%), respectively. We found that samples doped with x = 0.01 and x = 0.05 of Yb and Ce showed a better inhibitory effect on HCT-116 cancer cells than unadded ZnO (x = 0.00). The IC50 for HCT-116 cells of Ce and Yb co-doped ZnO nanoparticles was calculated and the IC50 values were x = 0.01 (3.50 µg/mL), x = 0.05 (8.25 µg/mL), x = 0.00 (11.75 µg/mL), and x = 0.03 (21.50 µg/mL). The treatment-doped ZnO NPs caused apoptotic cell death in the HCT-116 cells. The nanoparticles showed inhibitory action on both C. albicans and E. coli. It can be concluded that doping ZnO NPs with Yb and Ce improves their apoptotic effects on cancer and microbial cells.

An Evaluation of the Biocatalyst for the Synthesis and Application of Zinc Oxide Nanoparticles for Water Remediation—A Review

Global water scarcity is threatening the lives of humans, and it is exacerbated by the contamination of water, which occurs because of increased industrialization and soaring population density. The available conventional physical and chemical water treatment techniques are hazardous to living organisms and are not environmentally friendly, as toxic chemical elements are used during these processes. Nanotechnology has presented a possible way in which to solve these issues by using unique materials with desirable properties. Zinc oxide nanoparticles (ZnO NPs) can be used effectively and efficiently for water treatment, along with other nanotechnologies. Owing to rising concerns regarding the environmental unfriendliness and toxicity of nanomaterials, ZnO NPs have recently been synthesized through biologically available and replenishable sources using a green chemistry or green synthesis protocol. The green-synthesized ZnO NPs are less toxic, more eco-friendly, and more biocompatible than other chemically and physically synthesized materials. In this article, the biogenic synthesis and characterization techniques of ZnO NPs using plants, bacteria, fungi, algae, and biological derivatives are reviewed and discussed. The applications of the biologically prepared ZnO NPs, when used for water treatment, are outlined. Additionally, their mechanisms of action, such as the photocatalytic degradation of dyes, the production of reactive oxygen species (ROS), the generation of compounds such as hydrogen peroxide and superoxide, Zn2+ release to degrade microbes, as well as their adsorbent properties with regard to heavy metals and other contaminants in water bodies, are explained. Furthermore, challenges facing the green synthesis of these nanomaterials are outlined. Future research should focus on how nanomaterials should reach the commercialization stage, and suggestions as to how this ought to be achieved are presented.

Use of Nanoparticles to Prevent Resistance to Antibiotics-Synthesis and Characterization of Gold Nanosystems Based on Tetracycline

Antimicrobial resistance (AMR) is a serious public health problem worldwide which, according to the World Health Organization (WHO), requires research into new and more effective drugs. In this work, both gold nanoparticles covered with 16-3-16 cationic gemini surfactant (Au@16-3-16) and DNA/tetracycline (DNA/TC) intercalated complexes were prepared to effectively transport tetracycline (TC). Synthesis of the Au@16-3-16 precursor was carried out by using trihydrated gold, adding sodium borohydride as a reducing agent and the gemini surfactant 16-3-16 as stabilizing agent. Circular dichroism and atomic force microscopy techniques were then used to ascertain the optimal R range of the relationship between the concentrations of Au@16-3-16 and the DNA/TC complex (R = CAu@16-3-16/CDNA) that allow the obtainment of stable and compact nanosystems, these characteristics being fundamental for their use as antibiotic transporters. Stability studies over time were carried out for distinct selected Au@16-3-16 and Au@16-3-16/DNA-TC nanoformulations using the ultraviolet−visible spectrophotometry technique, checking their stability for at least one month. In addition, in order to know the charge and size distribution of the nanocomplexes, DLS and zeta potential measurements were performed in the solution. The results showed that the characterized nanosystems were highly charged, stable and of a reduced size (<100 nm) that allows them to cross bacterial membranes effectively (>1 μm). Once the different physicochemical characteristics of the gold nanosystems were measured, Au@16-3-16 and Au@16-3-16/DNA-TC were tested on Escherichia coli and Staphylococcus aureus to study their antibacterial properties and internalization capacity in microbes. Differences in the interaction of the precursors and the compacted nanosystems generated were observed in Gram-positive and Gram-negative bacteria, possibly due to membrane damage or electrostatic interaction with internalization by endocytosis. In the internalization experiments, depending on the treatment application time, the greatest bacterial destruction was observed for all nanoformulations explored at 18 h of incubation. Importantly, the results obtained demonstrate that both new nanosystems based on TC and Au@16-3-16 precursors have optimal antimicrobial properties and would be beneficial for use in patients, avoiding possible side effects.

Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview

Zinc oxide is a safe material for humans, with high biocompatibility and negligible cytotoxicity. Interestingly, it shows exceptional antimicrobial activity against bacteria, viruses, fungi, etc., especially when reduced to the nanometer size. As it is easily understandable, thanks to its properties, it is at the forefront of safe antimicrobials in this pandemic era. Besides, in the view of the 2022 European Green Deal announced by the European Commission, even science and nanotechnology are moving towards “greener” approaches to the synthesis of nanoparticles. Among them, biogenic ZnO nanoparticles have been extensively studied for their biological applications and environmental remediation. Plants, algae, fungi, yeast, etc., (which are composed of naturally occurring biomolecules) play, in biogenic processes, an active role in the formation of nanoparticles with distinct shapes and sizes. The present review targets the biogenic synthesis of ZnO nanoparticles, with a specific focus on their bioactive properties and antimicrobial application.

Enhancement of astaxanthin production in Haematococcus pluvialis using zinc oxide nanoparticles

Today, there is a great interest in using astaxanthin due to its potential health advantages. Application of different types of nanoparticles (NPs) as stress agents to enhance astaxanthin production in Haematococcus pluvialis, a microalgae strain, has been reported in the literature. In this study, the effect of different concentrations of zinc oxide (ZnO) NPs on the enhancement of astaxanthin production in H. pluvialis was investigated. First, ZnO NPs were synthesized from zinc nitrate as the precursor and sodium hydroxide (chemical method), and peel extract of pomegranate (green method) as reducing agents. To study the cell viability and stimulate the astaxanthin production, H. pluvialis cells were exposed to the different concentrations (i.e. 50, 100, 200, and 400 μg.ml^-1) of ZnO NPs. The synthesized powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) methods. The characterization results showed that the pure ZnO NPs were successfully synthesized via both methods with uniform particle size distribution. But, the average particle size of the green synthesized ZnO NPs (about 30 nm) was smaller than that of the chemically synthesized ones (about 80 nm). Maximum astaxanthin production (~ 20 mg.g^-1 of dry biomass of H. pluvialis) was achieved at 100 μg.ml^-1 of green synthesized ZnO NPs exposure to the H. pluvialis in comparison with the control culture after 15 days. However, ZnO NPs concentration above 200 μg.ml^-1 was toxic to the microalgae. From these results, it can be concluded that a specific amount of ZnO NPs could be considered as a worthy candidate for the enhancement of astaxanthin production in H. pluvialis.

Anti-microbial and anti-cancer activities of Mn0.5Zn0.5DyxFe2-xO4 (x ≤ 0.1) nanoparticles

Combining two or more nanoparticles is a promising approach. Previously we have reported synthesis of nanoparticles Dysprosium (Dy) substituted with manganese (Mn) zinc (Zn) by using ultrasonication method. The five different nanoparticles (NPs) Mn0.5Zn0.5DyxFe2-xO4 (x ≤ 0.1) have been structurally and morphologically characterized but there is no report on the biological application of these NPs. In the present study, we have examined the anti-cancer, anti-bacterial, and anti-fungal activities of Mn0.5Zn0.5DyxFe2-xO4 (x ≤ 0.1) NPs. Human colorectal carcinoma cells (HCT-116) were tested with different concentrations of NPs by using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. In addition, the impact of NPs was also examined on normal cells such as human embryonic kidney cells, HEK-293. After 48 h of treatment, Mn0.5Zn0.5DyxFe2-xO4 NPs (x = 0.02, 0.04 and 0.06) showed no inhibitory action on cancer cell's growth and proliferation, whereas Mn0.5Zn0.5DyxFe2-xO4 NPs (x = 0.08 and 0.1) showed profound inhibitory action on cancer cell's growth and proliferation. However, the treatment of Mn0.5Zn0.5DyxFe2-xO4 NPs on the normal cells (HEK-293) did not show cytotoxic or inhibitory action on HEK-293 cells. The treatment of Mn0.5Zn0.5DyxFe2-xO4 NPs (x ≤ 0.1) also inhibited both the bacteria (Escherichia coli ATCC35218 and Staphylococcus aureus) with lowest MIC and MBC values of 4 and 8 mg/mL and fungus (Candida albicans) with MIC and MFC values of 4 and 8 mg/mL on treatment with x = 0.08 and 0. 1.

Unlocking the potential of biosynthesized zinc oxide nanoparticles for degradation of synthetic organic dyes as wastewater pollutants

The azo dyes released into water from different industries are accumulating in the water bodies and bioaccumulating within living systems thereby affecting environmental health. This is a major concern in developing countries where stringent regulations are not followed for the discharge of industrial waste into water bodies. This has led to the accumulation of various pollutants including dyes. As these developing countries also face acute water shortages and due to the lack of cost-effective systems to remove these pollutants, it is essential to remove these toxic dyes from water bodies, eradicate dyes, or generate fewer toxic derivatives. The photocatalysis mechanism of degradation of azo dyes has gained importance due to its eco-friendly and non-toxic roles in the environment. The zinc nanoparticles act as photocatalysts in combination with plant extracts. Plant-based nanoparticles over the years have shown the potential to degrade dyes efficiently. This is carried out by adjusting the dye and nanoparticle concentrations and combinations of nanoparticles. Our review article considers increasing the efficiency of degradation of dyes using zinc oxide (ZnO) nanoparticles and understanding the photocatalytic mechanisms in the degradation of dyes and the toxic effects of these dyes and nanoparticles in different tropic levels.

Green Synthesized ZnO Nanoparticles Mediated by Streptomyces plicatus: Characterizations, Antimicrobial and Nematicidal Activities and Cytogenetic Effects

Zinc oxide nanoparticles (ZnO-NPs) are regarded as one of the most promising kinds of materials in a variety of fields, including agriculture. Therefore, this study aimed to biosynthesize and characterize ZnO-NPs and evaluate their different biological activities. Seven isolates of actinomycetes were obtained and screened for ZnO-NPs synthesis. The isolate MK-104 was chosen and identified as the Streptomyces plicatus MK-104 strain. The biosynthesized ZnO-NPs exhibited an absorbance peak at 350 nm and were spherical in shape with an average size of 21.72 ± 4.27 nm under TEM. XRD and DLS methods confirmed these results. The biosynthesized ZnO-NPs demonstrated activity against plant pathogenic microbes such as Erwinia amylovora, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Fusarium moniliform and Alternaria alternata, with MIC values ranging from 15.6 to 500 µg/mL. Furthermore, ZnO-NPs had a significant effect on Meloidogyne incognita, with death percentages of 88.2, 93.4 and 96.72% after 24, 48 and 72 h of exposure, respectively. Vicia faba seeds were treated with five concentrations of ZnO-NPs (12.5, 25, 50, 100 and 200 µg/mL). Low-moderate ZnO-NP concentrations (12.5-50 µg/mL) were shown to promote seed germination and seedling development, while the mitotic index (MI) decreased as the dosage of ZnO-NPs increased. Micronuclei (MNs) and the chromosomal abnormality index increased as well.

Diagnostic deficiencies of C. difficile infection among patients in a tertiary hospital in Saudi Arabia: A laboratory-based case series

Clostridioides difficile infection (CDI) has become a threatening public health problem in the developed world. In the kingdom of Saudi Arabia, prevalence of CDI is still unknown due to limited surveillance protocols and diagnostic resources. We used a two-step procedure to study and confirm C. difficile cases. We also studied toxin profiles of these isolates. Stool samples were collected from symptomatic patients and clinically suspected of CDI for almost 12 months. Isolates were confirmed by culture method followed by 16S rRNA sequencing. Multiplex PCR was performed for the identification of toxin A, toxin B and binary toxin genes and compared to Gene Expert results. Out of the 47 collected samples, 27 were successfully grown on culture media. 18 samples were confirmed as C. difficile by both culture and 16S rRNA sequencing. Interestingly, the rest of the isolates (9 species) belonged to different genera. Our results showed 95% of samples were positive for both toxin A and B (tcdA, tcdB) and all samples exhibited the toxin gene regulator tcdC. All samples were confirmed negative for the binary toxin gene ctdB and 11% of the isolates were positive for ctdA gene. Interestingly, one isolate harbored the binary toxin gene (cdtA ⁺) and tested negative for both toxins A and B. We believe that combining the standard culture method with molecular techniques can make the detection of C. difficile more accurate.

Biological Nanofactories: Using Living Forms for Metal Nanoparticle Synthesis

Metal nanoparticles are nanosized entities with dimensions of 1-100 nm that are increasingly in demand due to applications in diverse fields like electronics, sensing, environmental remediation, oil recovery and drug delivery. Metal nanoparticles possess large surface energy and properties different from bulk materials due to their small size, large surface area with free dangling bonds and higher reactivity. High cost and pernicious effects associated with the chemical and physical methods of nanoparticle synthesis are gradually paving the way for biological methods due to their eco-friendly nature. Considering the vast potentiality of microbes and plants as sources, biological synthesis can serve as a green technique for the synthesis of nanoparticles as an alternative to conventional methods. A number of reviews are available on green synthesis of nanoparticles but few have focused on covering the entire biological agents in this process. Therefore present paper describes the use of various living organisms like bacteria, fungi, algae, bryophytes and tracheophytes in the biological synthesis of metal nanoparticles, the mechanisms involved and the advantages associated therein.

Nanoparticles as therapeutic options for treating multidrug-resistant bacteria: research progress, challenges, and prospects

Resistance to antimicrobial agents has been alarming in recent years and poses a huge public health threat globally according to the WHO. The increase in morbidity and mortality resulting from microbial infections has been attributed to the emergence of multidrug-resistant microbes. Associated with the increase in multidrug resistance is the lack of new and effective antimicrobials. This has led to global initiatives to identify novel and more effective antimicrobial agents in addition to discovering novel and effective drug delivery and targeting methods. The use of nanoparticles as novel biomaterials to fully achieve this feat is currently gaining global attention. Nanoparticles could become an indispensable viable therapeutic option for treating drug-resistant infections. Of all the nanoparticles, the metals and metal oxide nanoparticles appear to offer the most promise and have attracted tremendous interest from many researchers. Moreover, the use of nanomaterials in photothermal therapy has received considerable attention over the years. This review provides current insight on antimicrobial resistance as well as the mechanisms of nanoparticle antibacterial activity. It offers an in-depth review of all the recent findings in the use of nanomaterials as agents against multi-resistant pathogenic bacteria. Also, nanomaterials that can respond to light stimuli (photothermal therapy) to kill microbes and facilitate enhanced drug delivery and release are discussed. Moreover, the synergistic interactions of nanoparticles with antibiotics and other nanomaterials, microbial adaptation strategies to nanoparticles, current challenges, and future prospects were extensively discussed.

Phytomolecules-Coated NiO Nanoparticles Synthesis Using Abutilon indicum Leaf Extract: Antioxidant, Antibacterial, and Anticancer Activities

BACKGROUND

NiO nanoparticles have attracted much attention due to their unique properties. They have been synthesized using chemical and physical techniques that often need toxic chemicals. These toxic chemicals cannot easily be removed from the nanoparticle's surface, make them less biocompatible, and limit their biological applications. Instead, plants based green synthesis of nanoparticles uses phytomolecules as reducing and capping agents. These phytomolecules are biologically active with no or less toxic effects.

MATERIALS AND METHODS

Phytomolecules-coated NiO nanoparticles were synthesized employing a green route using Abutilon indicum leaf extract. For comparative study, we also have synthesized NiO nanoparticles using the co-precipitation method. Synthesized nanoparticles were successfully characterized using different spectroscopic techniques. The synthesized nanoparticles were evaluated for antibacterial activity with agar well diffusion assay against different bacteria compared to standard drug and plant extract. They are also examined for anticancer potential using MTT assay against HeLa cancer cells, and further, their antioxidant potential was determined using DPPH assay. Biocompatibility of the synthesized nanoparticles was assessed against fibroblast cells.

RESULTS

Phytomolecules-coated NiO nanoparticles were demonstrated superior antibacterial and anticancer performance against bacteria (E. coli, B. bronchiseptica, B. subtilis, and S. aureus) by presenting highest zone of inhibitions (18 ± 0.58 mm, 21 ± 0.45 mm, 22 ± 0.32 mm, and 23 ± 0.77 mm) and HeLa cancer cells by exhibiting the least cell viability percentage (51.74 ± 0.35%) compared to plant extract and chemically synthesized NiO nanoparticles but were comparable to standard antibiotic and anticancer drugs, respectively. Phytomolecules-coated NiO nanoparticles were also demonstrated excellent antioxidant activity (79.87 ± 0.43% DPPH inhibition) and biocompatibility (> 90% cell viability) with fibroblast cells.

CONCLUSION

Nanoparticle synthesis using the Abutilon indicum leaf extract is an efficient and economical method, produces biocompatible and more biologically active nanoparticles, which can be an excellent candidate for therapeutic applications.

Development of bactericidal spinel ferrite nanoparticles with effective biocompatibility for potential wound healing applications

The current study was devised to explore the antibacterial activity and underlying mechanism of spinel ferrite nanoparticles (NPs) along with their biocompatibility and wound healing potentials. In this regard, nickel ferrite and zinc/nickel ferrite NPs were synthesized via a modified co-precipitation method and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy Energy-dispersive X-ray spectroscopy (EDX). The biocompatibility of the synthesized NPs with human dermal fibroblast (HDF) and red blood cells (RBCs) was assessed. The biocompatible concentrations of the NPs were used to investigate the antimicrobial activity against various pathogenic Gram-negative and Gram-positive bacteria. The mode of bactericidal action was also explored. In vitro scratch assay was performed to evaluate the wound healing potential of NPs. The SEM-EDX analysis showed that the average particles size of nickel ferrite and zinc/nickel ferrite were 49 and 46 nm, respectively, with appropriate elemental composition and homogenous distribution. The XRD pattern showed all the characteristic diffraction peaks of spinel ferrite NPs, which confirmed the synthesis of the pure phase cubic spinel structure. The biocompatible concentration of nickel ferrite and zinc/nickel ferrite NPs was found to be 250 and 125 μg ml-1, respectively. Both the NPs showed inhibition against all the selected strains in the concentration range of 50 to 1000 μg ml-1. Studies on the underlying antimicrobial mechanism revealed damage to the cell membrane, protein leakage, and intracellular reactive oxygen species production. The in vitro scratch assay confirmed the migration and proliferation of fibroblast with artificial wound shrinkage. This study shows that nickel ferrite and zinc/nickel ferrite NPs could be a strong candidate for antibacterial and wound healing nano-drugs.

Ecofriendly Synthesis of Silver Nanoparticles by Terrabacter humi sp. nov. and Their Antibacterial Application against Antibiotic-Resistant Pathogens

It is essential to develop and discover alternative eco-friendly antibacterial agents due to the emergence of multi-drug-resistant microorganisms. In this study, we isolated and characterized a novel bacterium named Terrabacter humi MAHUQ-38^T, utilized for the eco-friendly synthesis of silver nanoparticles (AgNPs) and the synthesized AgNPs were used to control multi-drug-resistant microorganisms. The novel strain was Gram stain positive, strictly aerobic, milky white colored, rod shaped and non-motile. The optimal growth temperature, pH and NaCl concentration were 30 °C, 6.5 and 0%, respectively. Based on 16S rRNA gene sequence, strain MAHUQ-38^T belongs to the genus Terrabacter and is most closely related to several Terrabacter type strains (98.2%-98.8%). Terrabacter humi MAHUQ-38^T had a genome of 5,156,829 bp long (19 contigs) with 4555 protein-coding genes, 48 tRNA and 5 rRNA genes. The culture supernatant of strain MAHUQ-38^T was used for the eco-friendly and facile synthesis of AgNPs. The transmission electron microscopy (TEM) image showed the spherical shape of AgNPs with a size of 6 to 24 nm, and the Fourier transform infrared (FTIR) analysis revealed the functional groups responsible for the synthesis of AgNPs. The synthesized AgNPs exhibited strong anti-bacterial activity against multi-drug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 6.25/50 and 12.5/50 μg/mL, respectively. The AgNPs altered the cell morphology and damaged the cell membrane of pathogens. This study encourages the use of Terrabacter humi for the ecofriendly synthesis of AgNPs to control multi-drug-resistant microorganisms.

Biogenic Silver Nanoparticles Synthesized by Lysinibacillus xylanilyticus MAHUQ-40 to Control Antibiotic-Resistant Human Pathogens Vibrio parahaemolyticus and Salmonella Typhimurium

The present study highlights a simple and eco-friendly method for the biosynthesis of silver nanoparticles (AgNPs) using Lysinibacillus xylanilyticus strain MAHUQ-40. Also, the synthesized AgNPs were used to investigate their antibacterial activity and mechanisms against antibiotic-resistant pathogens. Biosynthesis of AgNPs was confirmed by ultraviolet-visible spectroscopy, and then, they were characterized by field emission-transmission electron microscopy (FE-TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and fourier transform-infrared (FTIR). The toxicity of AgNPs against two pathogenic bacteria was evaluated. The UV-vis spectral scanning showed the peak for synthesized AgNPs at 438 nm. Under FE-TEM, the synthesized AgNPs were spherical with diameter ranges from 8 to 30 nm. The XRD analysis revealed the crystallinity of synthesized AgNPs. FTIR data showed various biomolecules including proteins and polysaccharides that may be involved in the synthesis and stabilization of AgNPs. The resultant AgNPs showed significant antibacterial activity against tested pathogens. The MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations) of the AgNPs synthesized by strain MAHUQ-40 were 3.12 and 12.5 μg/ml, respectively, against Vibrio parahaemolyticus and 6.25 and 25 μg/ml, respectively, against Salmonella Typhimurium. FE-TEM analysis showed that the biogenic AgNPs generated structural and morphological changes and damaged the membrane integrity of pathogenic bacteria. Our findings showed the potentiality of L. xylanilyticus MAHUQ-40 to synthesis AgNPs that acted as potent antibacterial material against pathogenic bacterial strains.

Biologically rapid synthesis of silver nanoparticles by Sphingobium sp. MAH-11T and their antibacterial activity and mechanisms investigation against drug-resistant pathogenic microbes

The present study highlights the biological synthesis of silver nanoparticles (AgNPs) using Sphingobium sp. MAH-11 and also their antibacterial mechanisms against drug-resistant pathogenic microorganisms. The nanoparticle synthesis method used in this study was reliable, facile, rapid, cost-effective and ecofriendly. The AgNPs exhibited the highest absorbance at 423 nm. The TEM image expressed spherical shape of AgNPs and the size of synthesized AgNPs was 7-22 nm. The selected area diffraction (SAED) pattern and XRD spectrum revealed the crystalline structure of AgNPs. The results of FTIR analysis disclosed the functional groups responsible for the reduction of silver ion to metal nanoparticles. The biosynthesized AgNPs showed strong anti-microbial activity against drug-resistant pathogenic microorganisms. Moreover, Escherichia coli and Staphylococcus aureus were used to explore the antibacterial mechanisms of biosynthesized AgNPs. Minimal inhibitory concentrations (MICs) of E. coli and S. aureus were 6.25 μg/mL and 50 μg/mL, respectively and minimum bactericidal concentrations (MBCs) of E. coli and S. aureus were 25 μg/mL and 100 μg/mL, respectively. Results exhibited that biosynthesized AgNPs caused morphological changes and injured the membrane integrity of strains E. coli and S. aureus. The AgNPs synthesized by Sphingobium sp. MAH-11 may serve as a potent antimicrobial agent for many therapeutic applications.

Zeolitic imidazolate framework-8 (ZIF-8) doped TiZSM-5 and Mesoporous carbon for antibacterial characterization

Drug resistant bacteria affects millions worldwide and remains a serious threat to health care system. The study reports the first application of hybrid nanocomposites based on zeolitic imidazolate framework-8 (ZIF-8) with MFI structured zeolite Ti-ZSM-5 (TiZ5) and mesoporous carbon (MC). The composite was designated as TiZ5/ZIF-8 and MC/ZIF-8 was studied for antibacterial activity. Bioactive components Zn2+ and 2-methyl imidazole present in ZIF-8 was found to exert significant antibacterial effect on Escherchia. coli and Staphyloccocus. No other antibiotic drugs are required. For comparative purpose, Fe-BTC MOF (BTC = 1,3,5-benzenetricarboxylate) was used as second set of nanoformulations (TiZ5/Fe-BTC and MC/Fe-BTC) but showed a lower antibacterial activity. The phase (X-ray diffraction), texture (BET surface area), coordination (DRS-UV-Vis), and morphology (TEM) was investigated. XRD showed the presence of nanosized ZIF-8 over TiZ5 and MC. Surface area calculation using N2 adsorption isotherm showed a reduction in the micropore surface area of ZIF-8 from 1148 m2/g to 224 m2/g (80%) and an increased meso surface area from 31 m2/g to 59 m2/g (90%). The mesopore pore volume increased significantly from 0.05 cm3/g to 0.12 m2/g. MC/ZIF-8 showed similar textural modifications. FT-IR spectra and DRS-UV-Vis spectra showed distinct composite formation with TiZ5, while a weak absorption of ZIF-8 observed over MC. TEM revealed the presence of nanocomposite MC/ZIF-8 and TiZ5/ZIF-8 distributed in nanosize ranging between 25 and 50 nm. TiZ5/ZIF-8 showed the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 0.5 and 1 mg/ml, respectively against E. coli. The MIC and MBC of TiZ5/ZIF-8 against S. aureus were 1 and 2 mg/ml, respectively. MC/ZIF-8 composite had second best antibacterial activity. This study shows that ZIF-8 based composite holds a great potential against E. coli and S. aureus.

Synthesis of Ni0.5Co0.5-xCdxFe1.78Nd0.02O4 (x ≤ 0.25) nanofibers by using electrospinning technique induce anti-cancer and anti-bacterial activities

Here we report the electrospinning synthesis of Cd-substituted Ni-Co ferrite Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) nanofiber (NFs) with a very low concentration of Nd as a dopant. The structure and surface morphology of the Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs were analyzed by X-ray powder pattern (XRD), transmission and scanning electron microscopes (TEM) along with Energy-dispersive X-ray (EDX). We have examined the biological applications of the Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs on both cancerous cells and bacterial cells. We have found that Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs produced inhibitory action on the human colorectal carcinoma cells (HEK-293) and also showed inhibitory action on the bacterial strains (S. aureus and E. coli) respectively. Finally, this is the first report on the synthesis of Cd- substituted Co-Ni ferrite nanofibers using electrospinning technique exhibiting anti-cancer and anti-bacterial activities.Communicated by Ramaswamy H. Sarma.

A Wild Fomes fomentarius for Biomediation of One Pot Synthesis of Titanium Oxide and Silver Nanoparticles for Antibacterial and Anticancer Application

The present study offers an alternative method for green synthesis of the formation of two types of nanoparticles (NPs). These NPs, titanium oxide and silver NPs (TiO₂ and Ag NPs, respectively), were obtained from the amalgamation of intracellular extract of a wild mushroom, Fomes fomentarius, with aqueous solutions of titanium isopropoxide and silver nitrate, respectively. F. fomentarius was identified phenotypically and by 18S ribosomal RNA gene sequencing (Gene accession no: MK635351). The biosynthesis of TiO₂ and Ag NPs was studied and characterized by X-ray diffraction (XRD), diffuse reflectance UV-Visible spectroscopy (DR-UV), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscope (TEM). Success was achieved in obtaining NPs of differing sizes and shapes. The antibacterial and anticancer activity of the NPs was significant with morphological damage being caused by both, although Ag NPs (10–20 nm) were found to have profound effects on bacterial and cancer cells in comparison to TiO₂ NPs (100–120 nm). These metal NPs, synthesized using wild mushrooms, hold a great potential in biomedicinedue to an effective enzyme combination, which permits them to modify different chemical compounds to less toxic forms, which is required for ecofriendly and safe biomaterials.

Green Synthesis of Silver Nanoparticles Using Pseudoduganella eburnea MAHUQ-39 and Their Antimicrobial Mechanisms Investigation against Drug Resistant Human Pathogens

Silver nanoparticles (AgNPs) have shown great promise in biomedical applications. The exact mechanism and mode of action of AgNPs regarding antimicrobial activity are still not well known. Moreover, synthesis of nanoparticles by physical and chemical methods is expensive and not ecofriendly. This study highlights the green, rapid, facile, cost-effective and ecofriendly synthesis of AgNPs using Pseudoduganella eburnea MAHUQ-39 and also investigates their antibacterial mechanisms. The transmission electron microscopy (TEM) image revealed a spherical shape of the AgNPs. The size of the synthesized AgNPs was 8 to 24 nm. The elemental mapping and selected area electron diffraction (SAED) and X-ray diffraction (XRD) patterns revealed the crystalline structure of AgNPs. Fourier-transform infrared spectroscopy (FTIR) analysis identified the functional groups that are involved in the reduction of silver ion to AgNPs. The green synthesized AgNPs exhibited strong antimicrobial activity against multidrug-resistant pathogenic microbes. Minimal inhibitory concentrations (MICs) of Staphylococcus aureus and Pseudomonas aeruginosa were 100 μg/mL and 6.25 μg/mL, respectively, and the minimum bactericidal concentrations (MBCs) of S. aureus and P. aeruginosa were 200 μg/mL and 50 μg/mL, respectively. Our data demonstrated that synthesized AgNPs created structural changes of cells and destroyed the membrane integrity of strains S. aureus and P. aeruginosa. Therefore, AgNPs synthesized by strain MAHUQ-39 can be used as a powerful antimicrobial agent for various therapeutic applications.

UsingFomitopsis pinicolafor bioinspired synthesis of titanium dioxide and silver nanoparticles, targeting biomedical applications

The current study proposes a bio-directed approach for the formation of titanium oxide and silver nanoparticles (TiO₂ and Ag NPs), using a wild mushroom, Fomitopsis pinicola, identified by 18S ribosomal RNA gene sequencing (gene accession no. MK635350) and phenotypic examination. NP synthesis was confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance UV-visible spectroscopy (DR-UV), and scanning and transmission electron microscopy (SEM/TEM). Furthermore, the impact of NPs on Escherichia coli and Staphylococcus aureus and a human colon cancer cell line (HCT) were evaluated by MIC/MBC and MTT assays, respectively, along with structural morphogenesis by different microscopy methods. The results obtained showed that TiO₂ and Ag NPs were found to be significantly active, however, slightly enhanced antibacterial and anticancer action was seen with Ag NPs (10–30 nm). Such NPs can be utilized to control and treat infectious diseases and colon cancer and therefore have potential in a range of biomedical applications.

This study proposes a bio-directed approach for the formation of titanium oxide and silver nanoparticles (TiO₂ and Ag NPs), using a wild mushroom, Fomitopsis pinicola, identified by 18S ribosomal RNA gene sequencing (gene accession no. MK635350) and phenotypic examination.

One-Pot Sonochemical Synthesis of ZnO Nanoparticles for Photocatalytic Applications, Modelling and Optimization

This present study proposed a successful one pot synthesis of zinc oxide nanoparticles (ZnO NPs) and their optimisation for photocatalytic applications. Zinc chloride (ZnCl2) and sodium hydroxide (NaOH) were selected as chemical reagents for the proposed study. The design of this experiment was based on the reagents' amounts and the ultrasonic irradiations' time. The results regarding scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy confirmed the presence of ZnO NPs with pure hexagonal wurtzite crystalline structure in all synthesised samples. Photocatalytic activity of the developed samples was evaluated against methylene blue dye solution. The rapid removal of methylene blue dye indicated the higher photocatalytic activity of the developed samples than untreated samples. Moreover, central composite design was utilised for statistical analysis regarding the obtained results. A mathematical model for the optimisation of input conditions was designed to predict the results at any given point. The role of crystallisation on the photocatalytic performance of developed samples was discussed in detail in this novel study.

Synthesis and biological characterization of Mn0.5Zn0.5EuxDyxFe1.8-2xO4 nanoparticles by sonochemical approach

Metallic nanoparticles (NPs) possess unique properties which makes them attractive candidates for various applications especially in field of experimental medicine and drug delivery. Many approaches were developed to synthesize divers and customized metallic NPs that can be useful in many areas such as, experimental medicine, drug design, drug delivery, electrical and electronic engineering, electrochemical sensors, and biochemical sensors. Among different metallic nanoparticles, manganese (Mn) NPs are the most prominent materials, in the present study, we have synthetized unique Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs by using ultrasonication method (x ≤ 0.1). The structure, and surface morphology of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs was characterized by XRD, SEM, TEM and EDX methods. We have examined the biological effects of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs on both normal (HEK-293) and cancerous (HCT-116) cells. We have found that the treatment of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs post 48 h, showed significant decline in cancer cells population as revealed by MTT assay. The IC₅₀ value of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs was ranged between (2.35 μg/mL to 2.33 μg/mL). To check the specificity of the actions, we found that the treatment of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs did not produce any effects on the normal cells, which suggest that Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs selectively targeted the cancerous cells. The anti-bacterial properties of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs were also evaluated by MIC and MBC assays. We suggest that Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs produced by sonochemical method possess potential anti-cancer and anti-bacterial capabilities.

Synthesis of Mn0.5Zn0.5SmxEuxFe1.8-2xO4 Nanoparticles via the Hydrothermal Approach Induced Anti-Cancer and Anti-Bacterial Activities

Manganese metallic nanoparticles are attractive materials for various biological and medical applications. In the present study, we synthesized unique Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ (0.01 ≤ x ≤ 0.05) nanoparticles (NPs) by using the hydrothermal approach. The structure and surface morphology of the products were determined by X-ray powder diffraction (XRD), transmission electron and scanning electron microcopies (TEM and SEM), along with energy dispersive X-ray spectroscopy (EDX). We evaluated the impact of Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ NPs on both human embryonic stem cells (HEK-293) (normal cells) and human colon carcinoma cells (HCT-116) (cancerous cells). We found that post-48 h of treatment of all products showed a significant decline in the cancer cell population as revealed by microscopically and the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay. The inhibitory concentration (IC₅₀) values of the products ranged between 0.75 and 2.25 µg/mL. When tested on normal and healthy cells (HEK-293), we found that the treatment of products did not produce any effects on the normal cells, which suggests that all products selectively targeted the cancerous cells. The anti-bacterial properties of the samples were also evaluated by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays, which showed that products also inhibited the bacterial growth.

Antibacterial and Antifungal Activity of Novel Synthesized Neodymium-Substituted Cobalt Ferrite Nanoparticles for Biomedical Application

Neodymium (Nd)-substituted cobalt ferrite nanoparticles (NPs), i.e., CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs, were synthesized by the sonochemical method. The compositional characterization was done by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Antistaphylococcal activity was found to be enhanced, i.e., survival rate was 50%, 45%, 40%, and 30% with the increase in the ratio of Nd (0.0 ≤ x ≤ 0.2), whereas anticandidal activity was found efficient, i.e., 9%, 20%, 22%, and 40% survival rate at all the four ratios. The morphogenesis studies indicated that the synthesized metal–ligand, improves the antimicrobial capacity by binding them strongly to the microbial walls. To the best of our knowledge, this is the first report which demonstrates the series of CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs being active towards Staphylococcus aureus and Candida albicans and encourages its potential candidature for pharmaceutical and biomedical purposes.

Cisplatin delivery, anticancer and antibacterial properties of Fe/SBA-16/ZIF-8 nanocomposite

Nanoformulation involving biocompatible MOFs and magnetic nanocarriers is an emerging multifunctional platform for drug delivery and tumor imaging in targeted cancer therapeutics. In this study, a nanocomposite has been developed comprising Fe/SBA-16 and ZIF-8 (Fe/S-16/ZIF-8) through ultrasonication. The drug delivery of cisplatin was studied using an automated diffusion cell system equipped with a flow type Franz cell. The anticancer activity of Fe/S-16/ZIF-8 was studied in vitro in MCF-7, HeLa cells and Human Foreskin Fibroblast (HFF-1) cells. XRD and d-spacing measurements of Fe/S-16/ZIF-8 using TEM revealed the presence of cubic-structured Fe₃O₄, γ-Fe₂O₄ (magnetite), and α-FeOOH (goethite) over an SBA-16/ZIF-8 nanocomposite. The composite showed a surface area of 365 m² g⁻¹, a pore size of 8.3 nm and a pore volume of 0.33 cm³ g⁻¹. VSM analysis of Fe/S-16/ZIF-8 showed that it possessed paramagnetic behavior with a saturated magnetization value of 2.39 emu g⁻¹. The Fe²⁺/Fe³⁺ coordination environment was characterized using diffuse reflectance spectroscopy. The cisplatin drug delivery study clearly showed the synergistic effects present in Fe/S-16/ZIF-8 with over 75% of cisplatin release as compared to that of Fe/S-16 and ZIF-8, which showed 56% and 7.5%, respectively. The morphology analysis of CP/Fe/SBA-16/ZIF-8 using TEM showed an effective transit of nanoparticles into MCF-7 cells. The lethal concentration (LC₅₀) of Fe/SBA-16/ZIF-8 for MCF-7 and HeLa cells is 0.119 mg mL⁻¹ and 0.028 mg mL⁻¹ at 24 h, respectively. For HFF-1 cells, the LC₅₀ is 0.016 mg mL⁻¹. The antibiofilm activity of Fe/SBA-16/ZIF-8 was investigated against biofilm-forming strains of drug resistant P. aeruginosa and MRSA by a microtiter tissue culture plate assay. Overall, nanosized ZIF-8 with a bioactive alkaloid imidazole inside the 3D cage type of SBA-16 pores is found to exhibit both anticancer and antibacterial properties. A Fe/S-16/ZIF-8 composite could be effectively used as a drug and drug delivery system against cancer and promote antibacterial activity.

The role of nano ZIF-8 in a Fe/SBA-16/ZIF composite has been explored as a potential anticancer drug and drug delivery system.