Bioinspired synthesis of zinc oxide nano-flowers: A surface enhanced antibacterial and harvesting efficiency

A nano-bioengineered cobalt oxide biostimulant mediated regulation of physiological, biochemical, and antioxidant mechanisms in Zea mays

Biogenic synthesized cobalt nanoparticles (NPs), dose optimization toxicity, and metabolic studies of Zea mays are very important before their application in the field. Here, we investigate the morphological, biochemical, and metabolic response of summer maize (Zea mays) against bulk cobalt chloride and Withania-assisted bioengineered cobalt NPs. It was found that cobalt chloride as bulk and concentration of 100 mg/L NPs inhibits growth via significant changes their metabolic and biochemical molecules. While biogenic assisted with Withania, cobalt NPs with concentrations of 50 and 100 mg/L have shown a significant increase in shoot length by 15% and 9% respectively. Root length was found to be decreased at 25 mg/L and 50 mg/L as compared to control. Fresh and dry weight was found to be increased at 25 mg/L and 50 mg/L. However, chlorophyll contents seemed to decline at 25 mg/L and increased at 50 mg/L. Carbohydrate content was found to be decreased at 50 mg/L and 25 mg/L by 76% and 70% respectively. Starch content was found to be increased at 25 mg/L and 50 mg/L by 28% and 33% respectively. Nitrate content was found to be decreased at 50 mg/L by 17%. However, higher tested concentrations showed a very much decrease in these compounds. Results displayed that a small quantity of cobalt oxide nanoparticles had a stimulatory impact on the seedling development while a higher quantity encouraged an inhibitory effect. 100 mg/L also showed an increase in activities when comparison was done against control. At 25 mg/L all activities were found to be maximum. This increased level suggests that the congregation of these secondary metabolites generates an oxidative response in plants when exposed to Cobalt oxide nanoparticles and cobalt chloride. However, further mechanistic research should be adopted as our experimental findings ruled out the generalized phytotoxicity of plants.

Attapulgite-Assisted In Situ Anchoring of Ultrasmall Ag Nanoparticles for Enhanced Eradication of Multidrug-Resistant Bacterial Biofilms and Accelerated Wound Healing

Silver nanoparticles (Ag NPs) have emerged as a promising solution to combat biofilm-related infections caused by multidrug-resistant bacteria. However, their practical application remains limited due to their tendency to aggregate and exhibit high toxicity at elevated concentrations. Here, we developed a Citrus limon peel water extract-mediated hydrothermal process to facilitate the heterogeneous nucleation of Ag NPs on attapulgite (APT) nanorods and prepared Ag/APT nanocomposites with ultrasmall Ag NPs (<2 nm) uniformly anchored on APT nanorods. Ascorbic acid and polyphenols in Citrus limon peel extract acted as electron donors to reduce Ag+ to Ag0, while the interfacial interaction of APT nanorods induced heterogeneous nucleation and confined the growth of Ag nanocrystals, resulting in ultrasmall Ag NPs. As a result, due to the synergistic effect of the targeted biofilm-binding affinity of APT nanorods and the siginificantly increased specific surface area of Ag NPs conducive to the release of Ag+ ions, the obtained Ag/APT nanocomposites exhibited enhanced eradication activities on antimicrobial-resistant bacterial biofilms and accelerated wound healing in MRSA-infected wound models. Additionally, attributing to the low dosage of Ag, Ag/APT exhibited exceptional biocompatibility both in vitro and in vivo. This work provides a simple and green strategy for the preparation of highly active Ag-based antibacterial nanomaterials and sheds new light on the development of advanced antimicrobial agents for wound healing.

Sustainable approach for fabrication of pineapple agro-waste mediated cellulose nanocrystals embedded with Ag/Ag2O/ZnO nanocomposites for efficient removal of waterborne pathogens in wastewater

Biogenic nanocomposites (NCs) effectively purify contaminated water by eliminating pollutants caused by rapid urbanization, unrestrained industrial activities, and the proliferation of pathogenic organisms, addressing the critical water contamination crisis impacting global health. This study describes the synthesis of a sustainable biopolymer NC (BNC) by incorporating pineapple (Murusi variety) crop residue-based Ag/Ag2O/ZnO NCs and cellulose nanocrystals (CNCs) through an eco-friendly and sustainable approach. TEM analysis revealed cross-sectional diameters of 11 nm consisting of spherical-shaped Ag/Ag2O NPs (9 nm) arranged on nanoflower-shaped ZnO NPs (82 nm). XRD analysis confirmed that biogenic Ag, Ag2O, and ZnO NPs exhibit space groups Fm3m, Pn-3m, and P63mc respectively with Ag/Ag2O NPs forming face-centered cubic and ZnO NPs wurtzite crystal structures. FTIR validated the pure CNCs formation, while TGA and differential thermogravimetry (DTG) demonstrated high thermal stability at 370 °C. Ag/Ag2O NPs exhibited outstanding antibacterial activity at 2000 ppm, with inhibition zones of 20 mm against E. coli and 21 mm against S. aureus. In contrast, ZnO NPs demonstrated lower antibacterial activity with inhibition zones of 13 mm against E. coli and 14 mm against S. aureus. The Ag/Ag₂O/ZnO NCs displayed significant antibacterial activity against both strains with inhibition zones of 19 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the NCs were determined to be 31.3 ppm and 62.5 ppm, respectively, for both bacterial strains. These findings highlight the superior antimicrobial properties of silver-based NCs compared to ZnO, suggesting their potential application in antimicrobial treatments. The developed BNC filter comprising of Ag/Ag2O/ZnO NCs 20 mg: CNCs: 50 g effectively removed Salmonella typhi from 1.2 L of contaminated wastewater through sequential filtration, exhibiting significant characteristics including sustainability, low production cost, water stability, easy recoverability, and high bacterial growth inhibition, making it a promising solution for water treatment applications.

Biosynthesized ZnO-based bimetallic nanocomposite for anticancer, antimicrobial, and photocatalytic applications

Industrial wastewater, particularly antibiotic-laden effluents, poses a significant environmental threat, necessitating efficient and sustainable remediation strategies. In this study, ZnO/Au nanocomposites were synthesized using Urtica dioica extract (ZnO/Au@UDE NCs), offering an eco-friendly alternative to conventional chemical methods. The NCs exhibited well-defined spherical and oval morphologies (40-50 nm), as confirmed by FTIR, TEM, and XRD analyses. Their photocatalytic efficiency in degrading penicillin G was optimized by adjusting key parameters, achieving rapid degradation within 130 min. The incorporation of gold nanoparticles significantly enhanced the electron-hole separation, thereby improving photocatalytic performance. Furthermore, ZnO/Au@UDE NCs demonstrated potent antibacterial activity against Escherichia coli and Pseudomonas aeruginosa (MIC: 125 µg/ml) and exhibited strong antioxidant and anticancer properties, with IC50 values of 72.49 µg/ml for MCF-7 and 23.63 µg/ml for AGS cancer cells. The combined photocatalytic and biological functionalities highlight the potential of these NCs for environmental remediation and biomedical applications, demonstrating a sustainable and multifunctional approach to nanomaterial development.

Synthesis of an antimicrobial chitosan film impregnated with ZnO nanoparticles phytosynthesized with Ruta graveolens plant extract

In this study, biopolymer of chitosan-based films were synthesized, which were impregnated with zinc oxide nanoparticles (ZnO NPs) at concentrations of 0, 1, 5 and 10 % w:v to obtain a film with microbicide properties and non-toxic for humans. The ZnO NPs were phytosynthesized with ethanolic extract of Ruta graveolens, by UV-Vis spectrophotometry and Tauc equation were estimated their Band gap energy = 3.37 eV at wavelength of 302 nm. The films characterization by FTIR spectroscopy, swelling test, TGA and DSC indicated that the linking of ZnO NPs with the biopolymer was successfully developed. Finally, to evaluate the potential application of the biopolymer in biomedicine, the microbicidal activity against pathogens Escherichia coli, Staphylococcus aureus and Candida albicans was evaluated. The analyses revealed that the microorganisms are susceptible to the doses of ZnO NPs present in the biopolymer. Resulting the biopolymers with 5 % w:v of ZnO NPs being the most efficient for inhibition zones of 33, 31 and 27 mm that were obtained for each microorganism respectively.

In vitro antioxidant and antibacterial activities of biogenic synthesized zinc oxide nanoparticles using leaf extract of Mallotus philippinensis Mull. Arg

The preparation of metallic nanoparticles (NPs) using the green method is rapid, eco-friendly, and easily scaled up at room temperature and pressure. In the current study, zinc oxide nanoparticles (ZnO NPs) were prepared utilizing leaf extract from Mallotus philippinensis, employing two distinct precursors of zinc oxide: zinc acetate and zinc nitrate. The antioxidant and antibacterial properties of the synthesized nanoparticles were also evaluated. The synthesis of ZnO NPs was preliminary monitored by UV-visible analysis. The biosynthesized nanoparticles were further characterized using a variety of techniques, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet-visible (UV-Vis) spectroscopy. XRD peaks showed that nanoparticles synthesized from both zinc precursors exhibit crystalline properties, having wurtzite hexagonal shapes. The TEM analysis indicates that the average crystallite size was determined to be 21 nm and 28 nm for zinc nitrate and zinc acetate as precursor. FTIR analysis confirmed the presence of polyphenolic compounds on the surface of the nanoparticles, which likely acted as reducing and capping agents during ZnO NP synthesis. The antioxidant activity of M. philippinensis-mediated ZnO NPs was assessed in vitro. ZnO NPs synthesized using zinc nitrate exhibited higher antioxidant potential (IC50 = 65.31 µg/ml) compared to those synthesized using zinc acetate (IC50 = 66.87 µg/ml). Furthermore, the ZnO NPs demonstrated significant antibacterial activity against both gram-positive and gram-negative bacteria, including Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Streptococcus pneumoniae (S. pneumoniae). The highest antibacterial activity was observed against S. pneumoniae, with a zone of inhibition of 14.97 ± 0.38 mm for ZnO NPs synthesized using zinc nitrate. These findings suggest that M. philippinensis leaf extract is an effective reducing and capping agent for the biosynthesis of ZnO NPs. The resulting nanoparticles exhibit potent antioxidant and antibacterial properties, highlighting their potential applications in biomedical and environmental fields.

Green Synthesis, Characterization and Pharmaceutical Applications of Biocompatible Zinc Oxide Nanoparticles Using Heliotropium rariflorum Stocks

Background: Zinc oxide nanoparticles are safe, non-toxic, and biocompatible. These NPs are used in food packaging materials, self-cleaning glass, ceramics, deodorants, sunscreens, paints, coatings, ointments, lotions, and as preservatives. This study explored the biological potential of ZnO nanoparticles synthesized using H. rariflorum. Methods: In vitro antibacterial and antifungal activities against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Candida albicans, Penicillium notatum, Aspergillus flavus, Aspergillus niger and Aspergillus solani were determined. Antioxidant activity was explored using the DPPH radical scavenging method. In vivo analgesic, antipyretic and sedative potential of synthesized nanoparticles was investigated using a mouse model. Results: SEM with various magnification powers showed that some particles were spherical while some were aggregated, flake-shaped, and hexagonal with rough and irregular surfaces. The EDX analysis revealed Zn (12.63%), O (22.83%) and C (63.11%) with trace quantities of Si (0.40%), Ca (0.54%) and P (0.49%). The XRD pattern indicated an amorphous state, with no peaks observed throughout the spectrum. The UV-visible spectrophotometry revealed a characteristic absorption peak at 375 nm, indicating the presence of ZnO nanoparticles. Fourier Transform Infrared Spectroscopy (FTIR) displayed several small peaks between 1793 and 2370 cm-1, providing evidence of the presence of different kinds of organic compounds with different functional groups. ZnO-NPs showed dose-dependent antibacterial and antifungal potential against all strains. Staphylococcus aureus and Candida albicans were the most susceptible strains. The nanoparticles exhibited a maximum antioxidant effect of 85.28% at 100 μg/mL. In this study, the acute toxicity test showed no mortality, and normal behavior was observed in mice at ZnO-NP doses of 5, 10, and 20 mg/kg. For analgesic and antipyretic activities, a two-way ANOVA revealed that dose, time, and the interaction between dose and time were significant. In contrast, the samples had a non-significant effect on sedative activity. Conclusions: This innovative study suggests a potential use of plant resources for managing microbes and treating various diseases, providing a scientific basis for the traditional use of H. rariflorum.

Chitosan-Copper Hybrid Nanoflowers: A Novel Nanopesticide for Controlling Rhizoctonia solani Infection in Crops

Copper-based nanomaterials are effective alternatives to traditional pesticides due to their antibacterial properties. However, the high cost and low dispersity limit their application. In this study, we synthesized cost-effective, eco-friendly, and stable chitosan-copper hybrid nanoflowers (CS-Cu HNFs) through facile self-assembly to manage agricultural diseases caused by the fungal pathogen (Rhizoctonia solani). The results show that CS-Cu HNFs, which utilized chitosan and copper phosphate as primary scaffolds, were formed via a series of nucleation, aggregation, self-assembly, and anisotropic growth processes. 200 mg/L CS-Cu HNFs exhibited an excellent inhibitory effect on R. solani, which was 6.11 times that of CuO nanoparticles, despite CS-Cu HNFs containing only 45% of Cu as that in CuO nanoparticles. Additionally, CS-Cu HNFs significantly reduced R. solani infection in various crops and displayed broad-spectrum antibacterial activity. This research provides new insights into the preparation and application of organic-inorganic hybrid nanoflowers as nanopesticides.

Biogenic zinc oxide nanoregulator determines the quantitative analysis of morpho-anatomical and antioxidant capacity in Lactuca sativa L

Zinc oxide nanoparticles (ZnO NPs) can possibly serve as a pervasive source of essential nutrient zinc in agricultural crops in the future. The major environmental concerns with ZnO NPs might be their toxicity and incorrect dosage, which might lead to crop damage and environmental pollution. Interplay between ZnO NPs and Lactuca sativa (L. sativa) will be of interest, yet little is known about apropos interaction of these two, which will assist in optimizing the dose of ZnO NPs for their commercial use in agriculture. The current study aimed to investigate the growth, anatomical, and antioxidative responses of L. sativa against ZnO NPs and zinc acetate. ZnO NPs were foliar sprayed with concentrations of 0, 25, 50, and 100 ppm. ZnO NPs remarkably promoted L. sativa growth, leaf water content, and biomass accumulation; however, they declined root growth. The foliar spray of ZnO NPs improved the thickness of the stem hypodermis, cortex, pericycle, and phloem, while decreasing the stem diameter, thickness of the epidermis, and number of vascular bundles. ZnO NPs rigorously declined the cell area of xylem but slightly improved it in phloem. Unlike stem cells' anatomical responses to ZnO NPs, the root cells behaved otherwise. Overall, the antioxidative activity of L. sativa considerably improved at 25 ppm concentration and decreased at 100 ppm. Generally, low and medium concentrations of ZnO NPs promoted plant morphological, anatomical, and antioxidant traits, while higher doses inhibited the same traits. Contrary to this, Zn acetate displayed severe toxic effects on almost all studied anatomical traits.

Synthesis, characterization, and evaluation of antibacterial and antifungal activities of CuO-ZnO-Co3O4 nanocomposites

The co-precipitation method was used to prepare CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite. The structural, morphological, and optical properties of the prepared samples were studied using X-ray diffraction (XRD), total reflection X-ray fluorescence (TXRF), transmission electron microscopy (TEM), selected area electron diffraction (SAED), diffuse reflectance spectroscopy (DRS), and zeta potential. XRD analysis revealed that the crystal structures of CuO, ZnO, and Co3O4 nanoparticles are monoclinic, hexagonal, and cubic, with average crystallite sizes of 30.8 nm, 31.8 nm, and 32.8 nm, respectively. For CuO-ZnO-Co3O4 nanocomposites, the corresponding sizes were 24.9 nm, 13.6 nm, and 16.1 nm. The optical bandgaps of CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposites were 1.5 eV, 3.14 eV, 1.2 eV, and 1.3 eV, respectively. In this study, the antibacterial activity of CuO-ZnO-Co3O4 nanocomposite against Gram-negative bacteria (E. coli, Klebsiella, pseudomonas, and Salmonella) and Gram-positive bacteria (Staphylococcus aureus) was investigated and compared with the antibiotic Azithromycin. In addition, the effect of the nanocomposite on fungi was studied and compared with the antifungal Mystatin.

Zinc oxide nanoparticles mediated salinity stress mitigation in Pisum sativum: a physio-biochemical perspective

Salinity is the major abiotic stress among others that determines crop productivity. The primary goal is to examine the impact of Zinc Oxide Nanoparticles (ZnO NPs) on the growth, metabolism, and defense systems of pea plants in simulated stress conditions. The ZnO NPs were synthesized via a chemical process and characterized by UV, XRD, and SEM. The ZnO NPs application (50 and 100) ppm and salt (50 mM and 100 mM) concentrations were carried out individually and in combination. At 50 ppm ZnO NPs the results revealed both positive and negative effects, demonstrating an increase in the root length and other growth parameters, along with a decrease in Malondialdehyde (MDA) and hydrogen peroxide concentrations. However, different concentrations of salt (50 mM and 100 mM) had an overall negative impact on all assessed parameters. In exploring the combined effects of ZnO NPs and salt, various concentrations yielded different outcomes. Significantly, only 50 mM NaCl combined with 50 ppm ZnO NPs demonstrated positive effects on pea physiology, leading to a substantial increase in root length and improvement in other physiological parameters. Moreover, this treatment resulted in decreased levels of MAD, Glycine betaine, and hydrogen peroxide. Conversely, all other treatments exhibited negative effects on the assessed parameters, possibly due to the high concentrations of both stressors. The findings offered valuble reference data for research on the impact of salinity on growth parameters of future agriculture crop.

Zinc oxide nano-fertilizer differentially effect on morphological and physiological identity of redox-enzymes and biochemical attributes in wheat (Triticum aestivum L.)

The aim of current study was to prepared zinc oxide nanofertilzers by ecofriendly friendly, economically feasible, free of chemical contamination and safe for biological use. The study focused on crude extract of Withania coagulans as reducing agent for the green synthesis of ZnO nano-particles. Biosynthesized ZnO NPs were characterized by UV-Vis spectroscopy, XRD, FTIR and GC-MS analysis. However, zinc oxide as green Nano fertilizer was used to analyze responses induced by different doses of ZnO NPs [0, 25, 50,100, 200 mg/l and Zn acetate (100 mg/l)] in Triticum aestivum (wheat). The stimulatory and inhibitory effects of foliar application of ZnO NPs were studied on wheat (Triticum aestivum) with aspect of biomass accumulation, morphological attributes, biochemical parameters and anatomical modifications. Wheat plant showed significant (p < 0.01) enhancement of growth parameters upon exposure to ZnO NPs at specific concentrations. In addition, wheat plant showed significant increase in biochemical attributes, chlorophyll content, carotenoids, carbohydrate and protein contents. Antioxidant enzyme (POD, SOD, CAT) and total flavonoid content also confirmed nurturing impact on wheat plant. Increased stem, leaf and root anatomical parameters, all showed ZnO NPs mitigating capacity when applied to wheat. According to the current research, ZnO NPs application on wheat might be used to increase growth, yield, and Zn biofortification in wheat plants.

Synthesis of carboxylated cellulose nanocrystal/ZnO nanohybrids using Oxytenanthera abyssinica cellulose and zinc nitrate hexahydrate for radical scavenging, photocatalytic, and antibacterial activities

The extremely low antioxidant, photocatalytic, and antibacterial properties of cellulose limit its application in the biomedical and environmental sectors. To improve these properties, nanohybrides were prepared by mixing carboxylated cellulose nanocrystals (CCNCs) and zinc nitrate hexahydrate. Data from FTIR, XRD, DLS, and SEM spectra showed that, ZnO nanoparticles, with a size ranging from 94 to 351 nm and the smallest nanoparticle size of 164.18 nm, were loaded onto CCNCs. CCNCs/ZnO1 nanohybrids demonstrated superior antibacterial, photocatalytic, and antioxidant performance. More considerable antibacterial activity was shown with a zone of inhibition ranging from 26.00 ± 1.00 to 40.33 ± 2.08 mm and from 31.66 ± 3.51 to 41.33 ± 1.15 mm against Gram-positive and Gram-negative bacteria, respectively. Regarding photodegradation properties, the maximum value (∼91.52 %) of photocatalytic methylene blue degradation was observed after 75 min exposure to a UV lamp. At a concentration of 125.00 μm/ml of the CCNC/ZnO1 nanohybrids sample, 53.15 ± 1.03 % DPPH scavenging activity was obtained with an IC50 value of 117.66 μm/ml. A facile, cost-effective, one-step synthesis technique was applied to fabricate CCNCs/ZnO nanohybrids at mild temperature using Oxytenanthera abyssinica carboxylated cellulose nanocrystals as biotemplate. The result showed that CCNCs/ZnO nanohybrids possess potential applications in developing advanced functional materials for dye removal and antibacterial and antioxidant applications.

Albumin-coated green-synthesized zinc oxide nanoflowers inhibit skin melanoma cells growth via intra-cellular oxidative stress

Zinc oxide (ZnO) has attracted a substantial interest in cancer research owing to their promising utility in cancer imaging and therapy. This study aimed to synthesized ZnO nanoflowers coated with albumin to actively target and the inhibit skin melanoma cells. We synthesized bovine serum albumin (BSA)-coated ZnO nanoflowers (BSA@ZnO NFs) and evaluated it's in vitro and in vivo therapeutic efficacy for skin cancer cells. BSA@ZnO NFs were prepared via single-step reduction method in the presence of plant extract (Heliotropium indicum) act as a capping agent, and further the successful fabrication was established by various physico-chemical characterizations, such as scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR) spectroscopy, and x-rays diffraction (XRD) analysis. The fabricated BSA@ZnO NFs appeared flower like with multiple cone-shaped wings and average hydration size of 220.8 ± 12.6 nm. Further, BSA@ZnO NFs showed enhanced cellular uptake and cytocidal effects against skin cancer cells by inhibiting their growth via oxidative stress compared uncoated ZnO NFs. Moreover, BSA@ZnO NFs showed enhance biosafety, blood circulation time, tumor accumulation and in vivo tumor growth inhibition compared to ZnO NFs. In short, our findings suggesting BSA@ZnO NFs as a promising candidate for various types of cancer treatment along with chemotherapy.

Proteomic insights to decipher nanoparticle uptake, translocation, and intercellular mechanisms in plants

Advent of proteomic techniques has made it possible to identify a broad spectrum of proteins in living systems. Studying the impact of nanoparticle (NP)-mediated plant protein responses is an emerging field. NPs are continuously being released into the environment and directly or indirectly affect plant's biochemistry. Exposure of plants to NPs, especially crops, poses a significant risk to the food chain, leading to changes in underlying metabolic processes. Once absorbed by plants, NPs interact with cellular proteins, thereby inducing changes in plant protein patterns. Based on the reactivity, properties, and translocation of nanoparticles, NPs can interfere with proteins involved in various cellular processes in plants such as energy regulation, redox metabolism, and cytotoxicity. Such interactions of NPs at the subcellular level enhance ROS scavenging activity, especially under stress conditions. Although higher concentrations of NPs induce ROS production and hinder oxidative mechanisms under stress conditions, NPs also mediate metabolic changes from fermentation to normal cellular processes. Although there has been lots of work conducted to understand the different effects of NPs on plants, the knowledge of proteomic responses of plants toward NPs is still very limited. This review has focused on the multi-omic analysis of NP interaction mechanisms with crop plants mainly centering on the proteomic perspective in response to both stress and non-stressed conditions. Furthermore, NP-specific interaction mechanisms with the biological pathways are discussed in detail.

Biosynthesis of silver nanoparticles by banana pulp extract: Characterizations, antibacterial activity, and bioelectricity generation

Here, green banana pulp extract (PE) has been used as a bio-reducing agent for the reduction of silver ions to silver nanoparticles (AgNPs). Bio-synthesized AgNPs were characterized by using UV, XRD, FEEM, TEM, and FTIR analysis. The face-centered cubic structures of AgNPs were formed with an average crystallite size of 31.26 nm and an average particle size of 42.97 nm. In this report, the electrical activities of green synthesized AgNPs have been evaluated along with the antibacterial activities. The antibacterial activities of AgNPs were evaluated against two pathogenic bacteria: Escherichia coli (gram-negative) and Staphylococcus epidermidis (gram-positive). AgNPs were added to the electrochemical cell and results demonstrated the improvement of power of the electrochemical cell. Green synthesized AgNPs showed excellent antibacterial activities against both gram-positive and negative bacteria and most importantly the NPs played an important role as an effective catalyst to enhance the electrical performance of bio-electrochemical cells. These significant findings may help in the advancement of nanotechnology in biomedical applications as well as in the creation of cheap and eco-friendly power generation devices.

Nano-Bio Interactions: Biofilm-Targeted Antibacterial Nanomaterials

Biofilm is a spatially organized community formed by the accumulation of both microorganisms and their secretions, leading to persistent and chronic infections because of high resistance toward conventional antibiotics. In view of the tunable physicochemical properties and the related unique biological behavior (e.g., size-, shape-, and surface charge-dependent penetration, protein corona endowed targeting, catalytic- and electronic-related oxidative stress, optical- and magnetic-associated hyperthermia, etc.), nanomaterials-based therapeutics are widely used for the treatment of biofilm-associated infections. In this review, the biological characteristics of biofilm are introduced. And the nanomaterials-based antibacterial strategies are further discussed via biofilm targeting, including preventing biofilm formation, enhancing biofilm penetration, disrupting the mature biofilm, and acting as drug delivery systems. In which, the interactions between biofilm and nanomaterials include mechanical disruption, electron transfer, enzymatic degradation, oxidative stress, and hyperthermia. Additionally, the current advances of nanomaterials for antibacterial nanomaterials by biofilm targeting are summarized. This review aims to present a complete vision of antibacterial nanomaterials-biofilm (nano-bio) interactions, paving the way for the future development and clinical translation of effective antibacterial nanomedicines.

Recent advances in nanoflowers: compositional and structural diversification for potential applications

In recent years, nanoscience and nanotechnology have emerged as promising fields in materials science. Spectroscopic techniques like scanning tunneling microscopy and atomic force microscopy have revolutionized the characterization, manipulation, and size control of nanomaterials, enabling the creation of diverse materials such as fullerenes, graphene, nanotubes, nanofibers, nanorods, nanowires, nanoparticles, nanocones, and nanosheets. Among these nanomaterials, there has been considerable interest in flower-shaped hierarchical 3D nanostructures, known as nanoflowers. These structures offer advantages like a higher surface-to-volume ratio compared to spherical nanoparticles, cost-effectiveness, and environmentally friendly preparation methods. Researchers have explored various applications of 3D nanostructures with unique morphologies derived from different nanoflowers. The nanoflowers are classified as organic, inorganic and hybrid, and the hybrids are a combination thereof, and most research studies of the nanoflowers have been focused on biomedical applications. Intriguingly, among them, inorganic nanoflowers have been studied extensively in various areas, such as electro, photo, and chemical catalysis, sensors, supercapacitors, and batteries, owing to their high catalytic efficiency and optical characteristics, which arise from their composition, crystal structure, and local surface plasmon resonance (LSPR). Despite the significant interest in inorganic nanoflowers, comprehensive reviews on this topic have been scarce until now. This is the first review focusing on inorganic nanoflowers for applications in electro, photo, and chemical catalysts, sensors, supercapacitors, and batteries. Since the early 2000s, more than 350 papers have been published on this topic with many ongoing research projects. This review categorizes the reported inorganic nanoflowers into four groups based on their composition and structure: metal, metal oxide, alloy, and other nanoflowers, including silica, metal-metal oxide, core-shell, doped, coated, nitride, sulfide, phosphide, selenide, and telluride nanoflowers. The review thoroughly discusses the preparation methods, conditions for morphology and size control, mechanisms, characteristics, and potential applications of these nanoflowers, aiming to facilitate future research and promote highly effective and synergistic applications in various fields.

Synthesis and Characterization of Silica, Silver-Silica, and Zinc Oxide-Silica Nanoparticles for Evaluation of Blood Biochemistry, Oxidative Stress, and Hepatotoxicity in Albino Rats

Evaluation of nanoparticles (NPs) for biomedical applications has received a lot of attention for detailed study on pharmacokinetics prior to clinical application. In this study, pure C-SiO₂ (crystalline silica) NPs and SiO₂ nanocomposites with silver (Ag) and zinc oxide (ZnO) were prepared by utilizing different synthesis routes such as sol-gel and co-precipitation techniques. The prepared NPs showed highly crystalline nature as confirmed by X-ray diffraction analysis where average crystallite sizes of 35, 16, and 57 nm for C-SiO₂, Ag-SiO₂, and ZnO-SiO₂ NPs, respectively, were calculated. Fourier transform infrared analysis confirmed the presence of functional groups related to the chemicals and procedures used for sample preparation. Due to agglomeration of the prepared NPs, the scanning electron microscope images showed large particle sizes when compared to their crystalline sizes. The optical properties of the prepared NPs such as absorption were obtained with UV-Vis spectroscopy. For in vivo biological evaluation, albino rats, both male and female, kept in different groups were exposed to NPs with 500 μg/kg dose. Hematological, serum biochemistry, histo-architecture, oxidative stress biomarkers, and antioxidant parameters in liver tissues along with various biomarkers for the evaluation of erythrocytes were estimated. The results on hemato-biochemistry, histopathological ailments, and oxidative stress parameters exhibited 95% alteration in the liver and erythrocytes of C-SiO₂ NPs-treated rats while 75 and 60% alteration in the liver tissues of rats due to exposure to Ag-SiO₂ and ZnO-SiO₂ NPs, respectively, when compared with the albino rats of the control (untreated) group. Therefore, the current study showed that the prepared NPs had adverse effects on the liver and erythrocytes causing hepatotoxicity in the albino rats in respective order C-SiO₂ > Ag SiO₂ > ZnO-SiO₂. As the C-SiO₂ NPs appeared to be the most toxic, it has been concluded that coating SiO₂ on Ag and ZnO reduced their toxicological impact on albino rats. Consequently, it is suggested that Ag-SiO₂ and ZnO-SiO₂ NPs are more biocompatible than C-SiO₂ NPs.

Emerging Advancements in Piezoelectric Nanomaterials for Dynamic Tumor Therapy

Cancer is one of the deadliest diseases, having spurred researchers to explore effective therapeutic strategies for several centuries. Although efficacious, conventional chemotherapy usually introduces various side effects, such as cytotoxicity or multi−drug resistance. In recent decades, nanomaterials, possessing unique physical and chemical properties, have been used for the treatment of a wide range of cancers. Dynamic therapies, which can kill target cells using reactive oxygen species (ROS), are promising for tumor treatment, as they overcome the drawbacks of chemotherapy methods. Piezoelectric nanomaterials, featuring a unique property to convert ultrasound vibration energy into electrical energy, have also attracted increasing attention in biomedical research, as the piezoelectric effect can drive chemical reactions to generate ROS, leading to the newly emerging technique of ultrasound−driven tumor therapy. Piezoelectric materials are expected to bring a better solution for efficient and safe cancer treatment, as well as patient pain relief. In this review article, we highlight the most recent achievements of piezoelectric biomaterials for tumor therapy, including the mechanism of piezoelectric catalysis, conventional piezoelectric materials, modified piezoelectric materials and multifunctional piezoelectric materials for tumor treatment.

Nano-managing silver and zinc as bio-conservational approach against pathogens of the honey bee

Herein, silver and zinc oxide Nanoparticles (NPs) were synthesized by using W. coagulant fruit extract as reducing agent and capping agent. The green synthesized NP with distinct properties were used for novel application against fungal and bacterial pathogen of honey bee (A. mellifera). The UV-spectroscopy confirms the synthesis of silver and zinc oxide NPs at 420 nm and 350 nm respectively. Further, XRD evaluated the monoclinic structure of Ag NPs while ZnO NPs showed wurtzite hexagonalcrystlized structure. Resistant honey bee pathogens such Paenibacilluslarvae, Melissococcus plutonius and Ascosphaera apis were isolated, identified and cultured in vitro to assess the antimicrobial potentials of Ag and ZnO NPs. Additionally, different biomolecules provide access to achieve maximum and stable Ag and ZnO NPs. It was also observed that with increasing the concentration of zinc oxide NPs and sliver NPs, zone of inhibition was also increased. Thus, present findings show that plant extracts can be a useful natural resource to prepare functional nonmaterial for targeted applications especially in the field of apicultural research.

Hydrothermally synthesized titanium/hydroxyapatite as photoactive and antibacterial biomaterial

The present work investigated hydrothermal synthesis of titanium/hydroxyapatite (Ti/HA) nanocomposite at varied Ti content. The synthesis was performed by coprecipitation method using CaO, ammonium dihydrogen phosphate and titanium oxide chloride precursor with the additional cetyl trimethyl ammonium chloride as templating agent, followed by hydrothermal treatment at 150 °C. The derived materials were characterized by x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy analyses. The photocatalytic properties of materials were tested on methyl violet (MV) photocatalytic oxidation, meanwhile the antibacterial testing was performed against Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, and Streptococcus pyogenes. In addition, cytotoxicity evaluation of the materials as potential biomaterial was also conducted. The results showed that physicochemical character of Ti/HA exhibits exhibit the excellent properties to be photocatalyst along with antibacterial activity. From the detail study of effect of varied titanium content ranging from 5 to 10 %wt., the increasing crystallite size of anatase phase of about 25.81 nm and 38.22 nm for Ti content of 5 and 10 % wt., respectively. In other side, the band gap energy value increases as the increasing Ti content, i.e. the values are 3.08; 3.18; and 3.20 eV for Ti content of 5, 10, 20 % wt., respectively. The band gap energy is correlated with the photocatalytic activity which the highest MV degradation was 96.46% over Ti/HA with 20% wt. of Ti (Ti20/HA). The nanocomposites also express the antibacterial activity with comparable minimum inhibitory concentration (MIC) with other similar Ti/HA nanocomposites. The MIC values of Ti20/HA against E. coli, S. aureus, K. pneumonia, and S. pyogenes are 25; 25; 50 and 50 μg/mL, respectively. In addition, the cytotoxicity test revealed the potency to be a biomimetic material as shown by severe toxicity.

Bioinspired Cobalt Oxide Nanoball Synthesis, Characterization, and Their Potential as Metal Stress Absorbants

Massive accumulation of heavy metals in agricultural land as a result of enhanced levels of toxicity in the soil is an emerging global concern. Among various metals, zinc contamination has severe effects on plant and human health through the food chain. To remove such toxicity, a nanotechnological neutralizer, cobalt oxide nanoballs (Co₃O₄ Nbs) were synthesized by using the extract of Cordia myxa. The Co₃O₄ Nbs were well characterized via UV-vis spectrophotometry, scanning electron microscopy, and X-ray diffraction techniques. Green-synthesized Co₃O₄ Nbs were exposed over Acacia jacquemontii and Acacia nilotica at different concentrations (25, 50, 75, and 100 ppm). Highly significant results were observed for plant growth by the application of Co₃O₄ Nbs at 100 ppm, thereby increasing the root length (35%), shoot length (48%), fresh weight (44%), and dry weight (40%) of the Acacia species with respect to the control. Furthermore, physiological parameters including chlorophyll contents, relative water contents, and osmolyte contents like proline and sugar showed a prominent increase. The antioxidant activity and atomic absorption supported and justified the positive response to using Co₃O₄ Nbs that mitigated the heavy-metal zinc stress by improving the plant growth. Hence, the biocompatible Co₃O₄ Nbs counteract the zinc toxicity for governing and maintaining plant growth. Such nanotechnological tools can therefore step up the cropping system and overcome toxicity to meet the productivity demand along with the development of agricultural management strategies.

Phyto-Mediated Controllable Synthesis of ZnO Clusters with Bactericidal Activity

The rapid development of antibiotic resistance has been considered a major threat to public health. Nanomaterials have risen to be an effective weapon to tackle this problem through multiple antibacterial mechanisms. The improved and tailored physiochemical properties of fine-tuned secondary nanoarchitectures contribute to the superior bactericidal actions of metal oxide structures. However, it is still challenging to construct secondary structures through mild green manufacturing methods. Here, we report the preferred antibacterial ZnO nanocrystal clusters formed by a green structure-tuning synthesis process, in which the primary ZnO nanoparticles with sizes <10 nm were assembled into different forms of clusters depending on the zinc salt concentration and temperature. ZnO clusters with a stable loose-assembly structure and a rougher surface exhibited better bactericidal ability with minimal inhibitory concentrations of 0.5 and 0.1 mg/mL against Escherichia coli and Staphylococcus aureus, respectively. The underlying mechanism is related to enhancing contact with bacteria, releasing small ZnO nanoparticles, and generating additional reactive oxygen species, which could aggravate the damage to bacterial cell membrane and eventually lead to bacterial death. Furthermore, attachment of phenolic compounds from olive leaf extract would promote membrane penetration by ZnO nanoparticles, resulting in the improvement of antibacterial activities, which profit from the green route mediated by Olea europaea leaf extract that could structure-tune ZnO nanocrystal clusters in one simple step that retains the active ingredients on the nanoparticles. This work proposes a feasible and clean strategy to improve the structure-bioactivity relationship of ZnO by controlling its growth into a preferable structure, and the developed ZnO clusters have a good prospect in antibacterial applications because of their excellent performance and green fabrication method.

Casting Zinc Oxide Nanoparticles Using Fagonia Blend Microbial Arrest

Physical and chemical methods for production of nanoparticles (NPs) are not only harmful for environment but also toxic for living organism. The present study attempts to synthesize ZnO NPs using the natural plant extract of Fagonia cretica. The phytochemical screening of F. cretica water extract was performed to check the presence of biologically active compounds like alkaloids, tannins, carbohydrates, proteins, phenols, saponins, flavonoids, and steroids. Well-prepared ZnO NPs given sharp absorption peak at 362 were confirmed by UV-visible. XRD analysis showed the ZnO NPs having wurtzite hexagonal structure with crystalline form. TEM analysis endorses flower-shaped ZnO nanoparticles ~ 100-1000 nm. FTIR spectrum suggested the involvement of phenolic groups and amino acids and amide linkages in protein performs as the stabilizing agent in the synthesis of ZnO NPs. The ZnO NPs showed strong antibacterial behavior against two bacterial strains Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. In addition, ZnO NPs exhibited strong antioxidant activity of 79%:85.6%:89.9% at 5 μg/mL:10 μg/mL:5 μg/mL concentration of ZnO NPs respectively. This work indicates that Fagonia is considered to be appropriate and promising candidate for extending the innovative applications in the field of medicine and industry and also helpful and useful to the scientific communities.

Incubating Green Synthesized Iron Oxide Nanorods for Proteomics-Derived Motif Exploration: A Fusion to Deep Learning Oncogenesis

The nanotechnological arena has revolutionized the diagnostic efficacies by investigating the protein corona. This displays provoking proficiencies in determining biomarkers and diagnostic fingerprints for early detection and advanced therapeutics. The green synthesized iron oxide nanoparticles were prepared via Withania coagulans and were well characterized using UV-visible spectroscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, and nano-LC mass spectrophotometry. Iron oxides were rod-shaped with an average size of 17.32 nm and have crystalline properties. The as-synthesized nanotool mediated firm nano biointeraction with the proteins in treatment with nine different cancers. The resultant of the proteome series was filtered oddly that highlighted the variant proteins within the differentially expressed proteins on behalf of nano-bioinformatics. Further magnification focused on S13_N, RS15, RAB, and 14_3_3 domains and few abundant motifs that aid scanning biomarkers. The entire set of variant proteins contracting to common proteins elucidates the underlining mechanical proteins that are marginally assessed using the robotic nanotechnology. Additionally, the iron rods indirectly possess a prognostic effect in manipulating expression of proteins through a smarter route. Thereby, such biologically designed nanotools provide a dual approach for medical studies.

Biomolecule-mimetic nanomaterials for photothermal and photodynamic therapy of cancers: Bridging nanobiotechnology and biomedicine

Nanomaterial-based phototherapy has become an important research direction for cancer therapy, but it still to face some obstacles, such as the toxic side effects and low target specificity. The biomimetic synthesis of nanomaterials using biomolecules is a potential strategy to improve photothermal therapy (PTT) and photodynamic therapy (PDT) techniques due to their endowed biocompatibility, degradability, low toxicity, and specific targeting. This review presents recent advances in the biomolecule-mimetic synthesis of functional nanomaterials for PTT and PDT of cancers. First, we introduce four biomimetic synthesis methods via some case studies and discuss the advantages of each method. Then, we introduce the synthesis of nanomaterials using some biomolecules such as DNA, RNA, protein, peptide, polydopamine, and others, and discuss in detail how to regulate the structure and functions of the obtained biomimetic nanomaterials. Finally, potential applications of biomimetic nanomaterials for both PTT and PDT of cancers are demonstrated and discussed. We believe that this work is valuable for readers to understand the mechanisms of biomimetic synthesis and nanomaterial-based phototherapy techniques, and will contribute to bridging nanotechnology and biomedicine to realize novel highly effective cancer therapies.

Controlled growth of ZnO nanoparticles using ethanolic root extract of Japanese knotweed: photocatalytic and antimicrobial properties

Synthesis of zinc oxide (ZnO) nanoparticles (NPs) was mediated by plant extracts to assist in the reduction of zinc atoms during the synthesis and act as a capping agent during annealing. The preparation used ethanolic extracts from the roots of Japanese knotweed (Fallopia japonica). Two major outcomes could be made. (i) A synergistic effect of multiple polyphenolic components in the extract is needed to achieve the capping effect of crystallite growth during thermal annealing at 450 °C characterized by an exponential growth factor (n) of 4.4 compared to n = 3 for bare ZnO. (ii) Synergism between the ZnO NPs and plant extracts resulted in superior antimicrobial activity against both Gram-positive bacteria, e.g., Staphylococcus aureus, and Gram-negative bacteria, e.g., Escherichia coli and Campylobacter jejuni. The materials were also tested for their antimicrobial activity against S. aureus under ultraviolet (UV) illumination. Also here, the photocatalyst prepared with plant extracts was found to be superior. The residues of the plant extract molecules on the surface of the catalyst were identified as the main cause of the observed differences, as proved by thermal gravimetry. Such a preparation using ethanolic extract of Fallopia japonica could serve as a more controlled synthesis of ZnO and potentially other metal oxides, with low environmental impact and high abundance in nature.

Crest to Trough Cellular Drifting of Green-Synthesized Zinc Oxide and Silver Nanoparticles

Green nanotechnology facilitates the blooming of zinc oxide (ZnO) and silver (Ag) nanoparticles (NPs) with distinct flowerlike and spherical morphologies, respectively. The well-characterized NPs with an average size of 35 nm (ZnO) and 25 nm (Ag) were functionalized on the cresty plates for antibacterial inhibition against Staphylococcus aureus and Pseudomonas aeruginosa, with the flowerlike ZnONPs exhibiting 90.9% inhibition and AgNPs exhibiting 100% inhibition. Further, the in vivo underwater troughs for hematological, immunological, and serological analysis in Labeo rohita exhibited 102 > 575 > 104 and 206 > 109 > 81% at concentrations of 1, 2, and 3 mg/L with 4-day and 15-day treatment, respectively, over ZnONPs. However, AgNPs exhibited 257 > 408 > 124 and 86 > 202 > 43% with 4-day and 15-day treatment, respectively, at the same concentrations. The classical ZnNPs and AgNPs exhibited excellent inhibition potential and significant transfiguration of hematological, enzymological, and protein parameters as safe nanomedicine, but ZnONPs were found to be 58, 69, 29 and 34, 51, 70% more active than AgNPs with 4-day and 15-day treatment, respectively. Therefore, the onset of ROX and antioxidant arena favors beneficial cellular drifting of NPs.

Inorganic Nanoflowers—Synthetic Strategies and Physicochemical Properties for Biomedical Applications: A Review

Nanoflowers, which are flower-shaped nanomaterials, have attracted significant attention from scientists due to their unique morphologies, facile synthetic methods, and physicochemical properties such as a high surface-to-volume ratio, enhanced charge transfer and carrier immobility, and an increased surface reaction efficiency. Nanoflowers can be synthesized using inorganic or organic materials, or a combination of both (called a hybrid), and are mainly used for biomedical applications. Thus far, researchers have focused on hybrid nanoflowers and only a few studies on inorganic nanoflowers have been reported. For the first time in the literature, we have consolidated all the reports on the biomedical applications of inorganic nanoflowers in this review. Herein, we review some important inorganic nanoflowers, which have applications in antibacterial treatment, wound healing, combinatorial cancer therapy, drug delivery, and biosensors to detect diseased conditions such as diabetes, amyloidosis, and hydrogen peroxide poisoning. In addition, we discuss the recent advances in their biomedical applications and preparation methods. Finally, we provide a perspective on the current trends and potential future directions in nanoflower research. The development of inorganic nanoflowers for biomedical applications has been limited to date. Therefore, a diverse range of nanoflowers comprising inorganic elements and materials with composite structures must be synthesized using ecofriendly synthetic strategies.

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.

Photocatalytic effect-assisted antimicrobial activities of acrylic resin incorporating zinc oxide nanoflakes

To overcome the deficiency of the antimicrobial effect of polymer, zinc oxide nanoparticles have been widely utilized as advanced nanofillers due to their antimicrobial and photocatalytic activity. However, the underlying antimicrobial mechanism has not been fully understood apart from topological and physical characteristics. In this study, we prepared zinc oxide nanoparticles-based acrylic resin to explore its antimicrobial mechanism under controlled mechanophysical conditions by using silane-treated zinc oxide nanoflakes (S-ZnNFs). S-ZnNFs incorporated acrylic resin (poly(methyl methacrylate), PMMA) composites up to 2 wt% were selected based on comparable mechanophysical properties (e.g., roughness, wettability, strength and hardness), possibly affecting antimicrobial properties beyond the zinc oxide nanoparticle effect, to bare PMMA. Antimicrobial adhesion results were still observed in 2 wt% S-ZnNFs incorporated PMMA using Candida albicans (C. albicans), one of the fungal infection species. In order to confirm the antimicrobial effects by photocatalysis, we pre-exposed the UV light on 2 wt% S-ZnNF composites before cell seeding, revealing synergetic antimicrobial effect via additional reactive oxygen species (ROS) generation to C. albicans over zinc oxide nanoparticle-induced one. RNA-seq analysis revealed distinguished cellular responses between zinc oxide nanoparticles and UV-mediated photocatalytic effect, but both linked to generation of intracellular ROS. Thus, the above data suggest that induction of high intracellular ROS of C. albicans was the main antimicrobial mechanism under controlled mechanophysical parameters and synergetic ROS accumulation can be induced by photocatalysis, recapitulating a promising use of a S-ZnNFs or possibly zinc oxide nanoparticles as intracellular-ROS-generating antimicrobial nanofillers in acrylic composite for biomedical applications.

Antibiotic-free antimicrobial poly (methyl methacrylate) bone cements: A state-of-the-art review

Prosthetic joint infection (PJI) is the most serious complication following total joint arthroplasty, this being because it is associated with, among other things, high morbidity and low quality of life, is difficult to prevent, and is very challenging to treat/manage. The many shortcomings of antibiotic-loaded poly (methyl methacrylate) (PMMA) bone cement (ALBC) as an agent for preventing and treating/managing PJI are well-known. One is that microorganisms responsible for most PJI cases, such as methicillin-resistant S. aureus, have developed or are developing resistance to gentamicin sulfate, which is the antibiotic in the vast majority of approved ALBC brands. This has led to many research efforts to develop cements that do not contain gentamicin (or, for that matter, any antibiotic) but demonstrate excellent antimicrobial efficacy. There is a sizeable body of literature on these so-called "antibiotic-free antimicrobial" PMMA bone cements (AFAMBCs). The present work is a comprehensive and critical review of this body. In addition to summaries of key trends in results of characterization studies of AFAMBCs, the attractive features and shortcomings of the literature are highlighted. Shortcomings provide motivation for future work, with some ideas being formulation of a new generation of AFAMBCs by, example, adding a nanostructured material and/or an extract from a natural product to the powder and/or liquid of the basis cement, respectively.

Application of Zinc Oxide nanoflowers in Environmental and Biomedical Science

Zinc oxide (ZnO) nanostructures can be synthesized in nanoforms of spheres, rods, flowers, disks, walls, etc., among which nanoflowers have gained special attention due to their versatile biomedical and pollutant remedial applications in waste water and air. ZnO nanoflowers have an ultrasmall size with a huge surface area to volume ratio due to their hexagonal petal structures which render them superior compared to the nanoparticles of other shapes. The ZnO nanoflowers have bandgap energy equivalent to a semiconductor that makes them have unique photophysical properties. We have used the appropriate keywords in Google Scholar and PubMed to obtain the recent publications related to our topic. We have selected the relevant papers and utilized them to write this review. The different methods of synthesis of ZnO nanoflowers are chemical vapor deposition, facile hydrothermal, thermal evaporation, chemical reduction, bio route of synthesis, and solvothermal method, etc. which are mentioned in this review. ZnO nanoparticles are used in paints, cosmetics, and other products due to their high photocatalytic activity. The different applications of ZnO nanoflowers in the diagnosis of disease biomarkers, biosensors, catalysts, and the therapeutic process along with wastewater remediation and gas sensing applications will be discussed in this review.

Green approaches for the synthesis of metal and metal oxide nanoparticles using microbial and plant extracts

Green synthesis approaches are gaining significance as promising routes for the sustainable preparation of nanoparticles, offering reduced toxicity towards living organisms and the environment. Nanomaterials produced by green synthesis approaches can offer additional benefits, including reduced energy inputs and lower production costs than traditional synthesis, which bodes well for commercial-scale production. The biomolecules and phytochemicals extracted from microbes and plants, respectively, are active compounds that function as reducing and stabilizing agents for the green synthesis of nanoparticles. Microorganisms, such as bacteria, yeasts, fungi, and algae, have been used in nanomaterials' biological synthesis for some time. Furthermore, the use of plants or plant extracts for metal and metal-based hybrid nanoparticle synthesis represents a novel green synthesis approach that has attracted significant research interest. This review discusses various biosynthesis approaches via microbes and plants for the green preparation of metal and metal oxide nanoparticles and provides insights into the molecular aspects of the synthesis mechanisms and biomedical applications. The use of agriculture waste as a potential bioresource for nanoparticle synthesis and biomedical applications of biosynthesized nanoparticles is also discussed.

An outstanding role of novel virus-like heterojunction nanosphere BOCO@Ag as high performance antibacterial activity agent

The development of highly efficient photonic nanomaterials with synergistic biological effects is critical and challenging task for public hygiene health well-being and has attracted extensive interest. In this study, a type of near-infrared (NIR) driven, virus-like heterojunction was first developed for synergistic biological application. The Ag-coated Bi2CO5 nanomaterial (BOCO@Ag) demonstrated good biocompatibility, low cytotoxicity, high antibacterial activity and excellent light utilization stability. The synthesized BOCO@Ag performed a potential high photothermal conversion (efficiency~46.81%) to generate high temperatures when irradiated with near-infrared light illumination. As expected, compared to single Ag+ disinfection, BOCO@Ag can exhibit better antibacterial performance when combined with photothermal energy and released Ag+ . These results suggest that BOCO@Ag can be a promising photo-activate antimicrobial candidate and provide security for humans health and the environment treatment.

Synthesis of Cu-doped 2D-WS2 nanosheet-based nano-antibiotic materials for inhibiting E. Coli and S. aureus bacterial strains

A new class of nano-antibiotic materials must be developed to treat bacterial infectious diseases. In this context, the synthesizing Cu-metal incorporated WS2 nanosheet (Cu–WS2-NS)-based antibiotic materials might overcome such associated issues.

Synthesis, Characterization, Immune Regulation, and Antioxidative Assessment of Yeast-Derived Selenium Nanoparticles in Cyclophosphamide-Induced Rats

This article introduces an environmentally friendly and more economical method for preparing red selenium nanoparticles (Se-NPs) with high stability, good biocompatibility, and narrow size using yeast as a bio-reducing agent with high antioxidant, immune regulation, and low toxicity than inorganic and organic Se. The yeast-derived Se-NPs were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results revealed spherical-shaped particles of Se-NPs with an average diameter of 71.14 ± 18.17 nm, an amorphous structure, and surface enhancement with an organic shell layer, that provide precise geometry and stability in the formation of bio-inert gray or black Se-NPs instead of red Se-NPs. Furthermore, the addition of 0.3-0.8 mg/kg Se-NPs in the feed significantly improved the health of mice. As Se-NPs stimulated the oxidative state of mice, it significantly increased the level of GSH-Px, SOD, and AOC, and decreased the level of MDA. The yeast-derived Se-NPs alleviated the immunosuppression induced by cyclophosphamide, whereas protected the liver, spleen, and kidney of mice, stimulated the humoral immune potential of the mice, and significantly increased the levels of I g M, IgA, and I g G. These results indicated that the yeast-derived Se-NPs, as a trace element feed additive, increased the defense of the animal against oxidative stress and infectious diseases and therefore Se-NPs can be used as a potential antibiotic substitute for animal husbandry.

Bactericidal and Virucidal Activities of Biogenic Metal-Based Nanoparticles: Advances and Perspectives

Much progress has been achieved in the preparation and application of engineered nanoparticles (NPs) in the field of medicine, mainly for antibacterial and antiviral applications. In the war against bacteria and viruses, besides traditional antibiotics and antiviral drugs, metal-based nanoparticles, such as silver (AgNPs), copper (CuNPs), copper oxides (CuO-NPs), iron oxide (FeO-NPs), zinc oxide (ZnO-NPs), and titanium oxide (TiO2-NPs) have been used as potent antimicrobial agents. These nanoparticles can be synthesized by traditional methods, such as chemical and physical routes, or more recently by biogenic processes. A great variety of macro and microorganisms can be successfully used as reducing agents of metal salt precursors in the biogenic synthesis of metal-based NPs for antimicrobial activity. Depending on the nature of the biological agent, NPs with different sizes, aggregation states, morphology, surface coatings and charges can be obtained, leading to different antimicrobial effects. Considering the drug resistance to traditional therapies, the development of versatile nanomaterials with potent antimicrobial effects is under intensive investigation. In this sense, this review presents and discusses the recent progress in the preparation and application of metal-based nanoparticles biogenically synthesized for antibacterial and antivirus applications. The strength and limitations are critically discussed.

Synthesis of photocatalytic zinc oxide nanoflowers using Peltophorum pterocarpum pod extract and their characterization

Zinc oxide nanoflowers (ZnONFs) were prepared by employing the pod extract of Peltophorum pterocarpum as a green resource and characterized by various methods. UV–vis spectrum displayed a peak at 361 nm which confirmed the formation of ZnO nanoparticles. The optical band gap was calculated as 3.43 eV. FE-SEM images exposed the flower-like morphology and EDX portrayed strong signals for Zn and O. XRD studies substantiated signature peaks for the wurtzite phase of ZnONFs and the lattice parameters matched well with the literature. Mesoporous nature was confirmed by BET analysis which yielded a high specific surface area of 19.61 m2/g. FTIR bands at 420.48 and 462.92 cm−1affirmed the Zn and O bonding vibrations. The photocatalytic potential of the ZnONFs was successfully examined for the removal of methylene blue dye under natural solar light. The experimental data were fitted to Langmuir–Hinshelwood’s first-order equation and the kinetic constant was calculated as 0.0114 min–1.

A novel bimetallic (Fe/Bi)-povidone-iodine micro-flowers composite for photocatalytic and antibacterial applications

The present work describes the synthesis of polyvinylpyrrolidone (PVP) assisted Fe-BiOI based Fe/Bi-povidone‑iodine (Fe/Bi-P-I) micro-flowers based composite and its photocatalytic and antibacterial applications. The Fe/Bi-P-I micro-flowers-based composite material was synthesized using a simple co-precipitation method. The prepared Fe/Bi-P-I micro-flowers-based composite materials were characterized using various characterization techniques and tested against photocatalytic degradation of rhodamine B (RhB) dye and antibacterial analysis. The PVP or povidone‑iodine provides more exposure of reactive sites and oxygen vacancies, which leads to a high separation rate of photoinduced charge carriers, and migration, thereby 100% of photodegradation efficiency at 1 mg/L initial concentration of RhB dye towards the synthesized P-Fe-BiOI based micro-flowers composite. Interestingly, Povidone-Iodine in Fe/Bi-P-I micro-flowers-based composite might be advantageous for antimicrobial activity against both gram-negative (E. coli), and gram-positive (S. aureus) bacterial strains. Therefore, the prepared Fe/Bi-P-I micro-flowers-based composite improved both photocatalytic degradation of organic pollutants as well as high antimicrobial activity. The method of synthesizing the Bi/Fe-P-I micro flower composite in the present study is novel, facile, and economically viable.

Characterization and photocatalytic activity of ZnO nanoflowers synthesized using Bridelia retusa leaf extract

In the current work, the leaf extract of Bridelia retusa was used for the first time to synthesize zinc oxide nanoparticles (ZnONPs). A zinc nanoparticle-specific 364-nm peak was discerned via UV–Vis studies with a typical bandgap energy of 3.41 eV. FE-SEM micrographs revealed flower-shaped structure of the ZnONPs. EDS analysis corroborated the presence of zinc and oxygen. XRD spectrum established the wurtzite structure, sized at 11.06 nm. The mesoporous texture (4.89 nm) of the nanoparticles was deduced from BET analysis, proving a higher specific surface area than commercial ZnONPs. FTIR spectroscopy resulted in absorption bands typical for ZnONPs. Within a span of 165 min, under solar irradiation, the ZnONPs facilitated the photocatalytic degradation of Rhodamine B dye upto 94.74%. Exhibiting pseudo-first-order kinetics, the process had a degradation constant of 0.0109 min−1. It was concluded that numerous factors led to the high degradation efficiency. High values of bandgap energy and specific surface area, along with the mesoporous and crystalline nature of the ZnONPs led to the observed effect. The ZnONPs were also stabilized by the phytochemicals in the B. retusa leaves. The study is thus able to successfully demonstrate the huge potential in the field of environmental nanoremediation. The viability of using ZnONPs as solar photocatalysts for treating dye-laden industrial wastewater was thus attested.