A facile method of synthesis of cobalt ferrite (CoFe₂O₄) and nickel ferrite (NiFe₂O₄) nanoparticles (NPs) was developed using urea as a hydroxylating agent and Paederia foetida Linn. (family: Rubiaceae) leaf extract as a bio-template. The synthesised ferrite NPs were characterised in a detailed manner by powder X-ray diffraction (XRD), transmission electron microscopy, Fourier transform-infrared spectroscopy and vibrating sample magnetometer analysis. The XRD patterns revealed the formation of cubic face-centred phase for both CoFe₂O₄ and NiFe₂O₄ NPs. These quasi-spherical particles of CoFe₂O₄ and NiFe₂O₄ were shown to have sizes in the range of 10–80 and 5–50 nm, respectively. The photocatalytic activity of metal ferrites was evaluated in H₂O₂ assisted oxidative degradation of methylene blue (MB) and rhodamine B (RhB) under irradiation of solar light. Both metal ferrite photocatalysts exhibited pronounced activity in degradation of MB and RhB, respectively, but relatively higher activity was observed for NiFe₂O₄. After completion, the catalysts were recovered using an external magnet. Recycling of these recovered catalysts up to five times showed no noticeable change in the efficiency.

Dyes and lead (Pb²⁺) are toxic compounds that can contaminant water. In this study, magnesium oxide (MgO) nanoparticles (NPs) prepared using clove, i.e. Syzygium aromaticum extract [clove extract (CE)] were used for methylene blue (MB) removal and Pb²⁺ ion sensing in aqueous solution. Maximum 90% MB removal was achieved using MgO NPs. The MB adsorption on MgO NPs surface followed second-order kinetics and Langmuir isotherm. MB dye was adsorbed as a monolayer on the surface of MgO NPs with maximum adsorption capacity, 5555 mg g⁻¹. MgO NPs were also able to selectively detect lead (Pb²⁺) in 1 nM–200 µM range with 24 µM (3σ) limit of detection. So, CE prepared MgO NPs are useful for MB dye adsorption and metal ion sensing applications.

Synthesis of iron nanoparticles (INPs) with a biocompatible coating usually is a multistep process which requires harsh, special and protected reaction conditions. In the current experiment, the authors used Xanthomonas campestris cells to develop a facile method for fabrication of biocompatible INPs. Bacterial cells were supplied with ferric citrate as an iron precursor. Transmission electron microscopy micrographs exhibited that xanthan gum-coated INPs are synthesised and deposited on the surface of X. campestris cells and produced nanoparticles were 20–80 nm in diameter with 41.7 nm mean particle size. Xanthan gum coating with about 7 nm thickness formed a clear hollow around each nanoparticle. According to thermogravimetric analysis, the coating was about 13.4% of the total INPs weight. Prepared particles had a zeta potential of −114 mv which is an ideal surface charge to make particles colloidally stable in aqueous matrixes. Xanthan gum-coated INPs were non-crystalline with low saturation magnetisation value of about 0.26 emu/g.

The electrospinning technique was used for the nanofiber production of Alyssum lepidium mucilage with acetic acid and polyvinyl alcohol (PVA) polymer. Some parameters such as voltage, polymer concentration, tip-to-collector distance, and feed rate were optimised and applied for the fabrication of the nanofiber membranes of the seeds mucilage. The scanning electron microscopy images were used to find the optimised conditions for the electrospinning process. It was found that the aqueous solution of Alyssum mucilage/PVA (80:20), voltage (18 kV), polymer concentration (50%), tip-to-collector distance (10 cm) and feed rate (0.125 ml/h) could be successfully used to obtain uniform nanofibers with diameters as low as 139.9 nm. X-ray diffraction and Fourier transform infrared spectrometer analysis also proved the presence of the alyssum mucilage/PVA nanofiber. In this study, the used electrospun procedure was biodegradable, inexpensive, non-toxic, and maintainable enough to optimise the mucilage nanofiber fabrication as a new source, thereby improving the potential application of the nanofiber biomembrane in filtration and medical systems with biocompatible and biodegradable properties.

The synthesis of zinc sulphide nanoparticles (ZnS NPs) using a green approach was explored. The resulting nanoparticles (NPs) were characterised by UV–vis spectroscopy, scanning and transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The leishmanicidal, cytotoxic and antioxidant activity of the resulting synthesised ZnS NPs (<70 nm) were evaluated against Leishmania major (L. major) promastigotes and amastigotes by MTT assay and using a macrophage model. The ZnS NPs were able to counteract the effects of oxidative metabolites as demonstrated by the oxidant activity. The IC₅₀ value of butylated hydroxyanisole was 26.04 µg/ml as compared with the IC₅₀ for ZnS NPs (90.95 µg/ml). The NPs displayed no cytotoxicity for the murine macrophaghes as the selectivity index (SI) fell into the safety range (SI ≥ 10). These nanomaterials exhibited good antileishmanial activity against the L. major stages that were comparable to that of Glucantime, the drug of choice. The IC₅₀ values of ZnS NPs and Glucantime against amastigotes were 11.59 ± 2.51 and 4.95 ± 2.51 μg/ml, respectively. The IC₅₀ values for ZnS NPs and Glucantime versus promastigote were 29.81 ± 3.15 and 14.75 ± 4.05 μg/ml, respectively. Further investigation is essential to explore the biological effects of ZnS NPs on animal and/or clinical models.

Owing to the numerous biological applications, cost effectiveness and low cytotoxicity of the biomimetic nanoparticles (NPs), the authors optimised the production of silver NPs (AgNPs) using aqueous extract of Teucrium stocksianum Boiss. The NPs were characterised by ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS) and Fourier transform-infrared spectroscopy (FTIR). The UV-vis spectroscopy revealed a surface plasmon resonance (410-440 nm) at an incubation temperature of 90°C when 1 mM Ag nitrate combined to 5 mg/ml extract concentration in the ratio of 1:10. DLS results show an average zeta size of ∼44.61 nm and zeta potential of −15.3 mV. SEM and XRD confirmed the high crystallinity and cubical symmetry with an average size below 100 nm. FTIR measurement shows the presence of various functional groups, responsible for the capping and reduction of Ag metal. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay shows that AgNPs are less cytotoxic to J774 and L929 cells as compared with enhanced anticancer activity with low IC50 concentrations (68.24 µg/ml) against Michigan Cancer Foundation-7 (MCF-7) cells. The ethidium bromide/acridine orange assay shows that the AgNPs kill the cell by apoptosis. Overall, the results show that AgNPs possesses potent anticancer activities.

Biogenic synthesis of gold (Au), silver (Ag) and bimetallic alloy Au–Ag nanoparticles (NPs) from aqueous solutions using Cannabis sativa as reducing and stabilising agent has been presented in this report. Formation of NPs was monitored using UV–visible spectroscopy. Morphology of the synthesised metallic and bimetallic NPs was investigated using X-ray diffraction and scanning electron microscopy. Elemental composition and the surface chemical state of NPs were confirmed by energy dispersive X-ray spectroscopy analysis. Fourier transform-infrared spectroscopy was utilised to identify the possible biomolecules responsible for the reduction and stabilisation of the NPs. Biological applicability of biosynthesised NPs was tested against five bacterial strains namely Klebsiella pneumonia, Bacillus subtilis (B. subtilis), Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa (P. aeruginosa) and Leishmania major promastigotes. The results showed considerable antibacterial and anti-leishmanial activity. The Au–Ag bimetallic NPs showed improved antibacterial activity against B. subtilis and P. aeruginosa as compared to Au and Ag alone, while maximum anti-leishmanial activity was observed at 250 μg ml⁻¹ NP concentration. These results suggest that biosynthesised NPs can be used as potent antibiotic and anti-leishmanial agents.

Graphite nanosheets (GNSs) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposites were prepared by solution casting method. This study aimed to evaluate the effects of previously phototreatment with ultraviolet (UV) radiation on the biotreatment with Paecilomyces variotti of neat PHBV and PHBV/GNS nanocomposites. Some samples of PHBV film were submitted only to biotreatment with P. variotti during 120 days; other samples were subjected to phototreatment (UV radiation) for 30 h followed by biodegradation assessment with P. variotti for a period of 120 days. The effects of biotreatments on thermal properties were studied through differential scanning calorimetry. The PHBV films were monitored by weight changes as a function of time. Also, their surfaces were examined after the tests using scanning electron microscopy, contact angle and roughness measurements. The level of oxidation was recorded by means of carbonyl index evaluation by Fourier transformed infrared spectroscopy spectroscopy. The phototreatment of PHBV films influenced the process of adhesion and colonisation by P. variotti on the surface of the films, and enhanced morphological and structural changes.

Gold nanoflowers (GNFs) prepared by reduction of HAuCl₄ by ascorbic acid were capped with human serum albumin (HSA) by either electrostatic or covalent attachment to prevent their self-aggregation. Measurement of surface plasmon resonance absorbance changes under different stress conditions showed that GNFs stabilised by covalent attachment of HSA were more stable than those stabilised by electrostatic attachment. Cytotoxicity of the covalently conjugated GNF was also studied in cultured human oral cancer cell lines by measuring the metabolic activity via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

The interaction of La₂O₂CO₃ nanoparticles (La NPs) with human serum albumin (HSA) has been studied. Analysis of the fluorescence quenching data of HSA using Stern–Volmer method showed that La NPs quenched HSA fluorescence in static quenching mode. Thermodynamic analysis indicated that hydrogen bonds and Van der Waals interactions play a major role for HSA–La NPs associations. Fluorescent displacement measurements confirmed that the primary binding site of La NPs was mainly located within site I (subdomain IIA) of HSA. The binding distance was calculated by using Forster resonance energy transfer theory. Also, the results of Fourier-transform infrared spectroscopy, circular dichroism, three-dimensional fluorescence and UV–visible measurements indicated that the binding of above La NPs to HSA may induce conformational and micro-environmental changes of protein. This study suggested that the conformational change of HSA was at secondary structure of it and the biological activity of this protein was changed in the present of La NPs.

Medicinal plants are widely utilised by the African population since they have no harmful side effects and low cost compared with different treatments. The field of nanotechnology is the most active part of research in modern material's science. Though there are several chemicals as well as physical methods, however, green synthesis of nanomaterials is the most emerging method of synthesis. Conventionally, chemical reduction is the most often applied approach for the preparation of metallic nanoparticle's however, in most of the synthesis protocols it cannot avoid the utilisation of toxic chemicals. Hence, the authors report an environmentally friendly, cost effective and green approach for synthesis of 1 mM AgNO₃ solution using the polyphenolic-rich leaf extracts of Syzygium cumini (S. cumini) (L.) Skeels as a reducing and capping agent. The synthesised AgNPs are characterised by UV-Vis spectroscopy and Fourier transform infrared (FTIR) spectroscopy. FTIR analysis revealed that the AgNPs were stable due to eugenols, terpenes, and other different aromatic compounds present in the extract. The green biosynthesised S. cumini AgNPs significantly inhibited the growth of human pathogenic both gram-positive Staphylococcus aureus (1.40 mm) and gram-negative bacteria Escherichia coli (2.75 mm) and Salmonella typhimurium (1.45 mm) showing promising antimicrobial activity.

This study investigated synthesis and characterisation of Nano-PLGA (poly(lactic-co-glycolic acid))/CO (clove-oil) nanoparticles. The delivery of drug-loaded nanoparticles to demineralised dentin substrates and their morphological association with a two-step etch-and-rinse adhesive system was studied. The effect of Nano-PLGA/CO pretreatment on micro-tensile bond strength of resin-dentin bonding was scrutinised. This study employed CO-containing PLGA nanoparticles as a delivery vehicle for sustainable drug release inside dentinal-tubules for potential dental applications. Emulsion evaporation resulted in uniformly distributed negatively-charged Nano-PLGA/Blank and Nano-PLGA/CO nanoparticles. Scanning electron microscopy/ transmission electron microscopy revealed even spherical nanoparticles with smooth texture. High CO-loading and encapsulation were achieved. Moreover, controlled CO-release was evidenced after 15 days, in-vitro and ex-vivo. Nanoparticles exhibited low initial toxicity towards human mesenchymal stem cells with excellent antibacterial properties. Nanoparticles penetration inside dentinal-tubules indicated a close correlation with resin-tags. Nano-PLGA/CO pretreatment indicated reduction in short-term bond strength of resin-dentin specimens. Nano-PLGA/CO as model drug-loaded nanoparticles showed excellent metric and antibacterial properties, low toxicity and sustained CO release. However, the loading of nanoparticles with CO up to ∼10 mg (Nano-PLGA/CO:10) did not adversely affect short-term bond strength values. This drug-delivery strategy could be further expanded to deliver other pulp-sedative agents and medications with other dental relevance.

The biological method for synthesis of silver nanoparticles (AgNPs) using Bacopa monneri leaves and its anti-proliferation against human lung adenocarcinoma cell line (A549) was studied. The AgNPs synthesis was determined by an ultraviolet–visible spectrum and was confirmed primarily by the colour change and surface plasmon resonance was observed at 450 nm and its reduction of functional groups stretched in AgNPs was identified by Fourier transform infrared and the crystalline nature of AgNPs was confirmed by X-ray diffraction. The structural morphology of the AgNPs was found to be spherical and polygonal shape and size (> 35 nm) were determined by field emission scanning electron microscopy analysis and its purity was identified by energy dispersive analysis of X-rays (EDAX). A further, antibacterial activity of biosynthesised AgNPs against Gram negative and Gram positive bacteria was assessed. The cytotoxic effect of synthesised AgNPs was analysed against human lung adenocarcinoma cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The GI₅₀ was found to be 20 µg/ml at 24 h incubation. The apoptosis cells containing condensate and marginalised chromatin stages were analysed by propidium iodide staining and DNA damage was observed in A549 treated cells. The present study strongly emphasised that the bioactive molecule-coated AgNPs could have potential for biomedical applications and significant anticancer effects against human lung adenocarcinoma cells.

Multi-drug resistance in pathogenic bacteria has created immense clinical problem globally. To address these, there is need to develop new therapeutic strategies to combat bacterial infections. Silver nanoparticles (AgNPs) might prove to be next generation nano-antibiotics. However, improved efficacy and broad-spectrum activity is still needed to be evaluated and understood. The authors have synthesised AgNPs from Withania somnifera (WS) by green process and characterised. The effect of WS-AgNPs on growth kinetics, biofilm inhibition as well as eradication of preformed biofilms on both gram-positive and gram-negative pathogenic bacteria was evaluated. The authors have demonstrated the inhibitory effect on bacterial respiration and disruption of membrane permeability and integrity. It was found that WS-AgNPs inhibited growth of pathogenic bacteria even at 16 µg/ml. At sub-minimum inhibitory concentration concentration, there was approximately 50% inhibition in biofilm formation which was further validated by light and electron microscopy. WS-AgNPs also eradicated the performed biofilms by varying levels at elevated concentration. The bacterial respiration was also significantly inhibited. Interaction of WS-AgNPs with test pathogen caused the disruption of cell membrane leading to leakage of cellular content. The production of intracellular reactive oxygen species reveals that WS-AgNPs exerted oxidative stress inside bacterial cell causing microbial growth inhibition and disrupting cellular functions.

Drug delivery is one of the most important challenges in the domain of health. Non-toxic and biocompatible carriers are provided by human serum albumin nano-capsule (HSA/NC) for drug delivery applications. In this study, HSA, with high loadings of drug-modified cobalt ferrite (CoFe₂O₄) magnetic nanoparticle (CoFe₂O₄/MNPs) was fabricated for epirubicin anticancer drug delivery. In the initial step, CoFe₂O₄/MNPs was synthesised via co-precipitation technique and characterised by X-ray powder diffraction, vibrating sample magnetometry, energy dispersive X-ray analysis, scanning electron microscopy and map analysis. Furthermore, CoFe₂O₄/MNPs and epirubicin were loaded into HSA/NC and utilised as a novel system against breast cancer cell line (MCF-7). IC₅₀ for free epirubicin, unloaded CoFe₂O₄/MNPs/HSA/NC, CoFe₂O₄/MNPs and epirubicin-loaded CoFe₂O₄/MNPs/HSA/NC were 7.7, 2400, 840 and 430 μg/ml, respectively. The results obtained revealed high cytotoxicity effect of epirubicin-loaded CoFe₂O₄/MNPs on breast cancer cell line.

In this investigation, the biological synthesis method was adopted to synthesise silver nanoparticles (AgNPs) by using the leaf extracts of Cleistanthus collinus (C. collinus). This plant has traditionally been used to remove the harmful pest from the agriculture field. Leaf extract of C. collinus was used as bioreductant on the precursor solvent of AgNO₃. The synthesised AgNPs were characterised by spectroscopic method such as UV–vis spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy, dynamic light scattering and microscopic method by field-emission scanning electron microscopy analysis. The AgNPs were studied for both antibacterial and antifungal activities and found to exhibit potential antibacterial activity against Bacillus subtilis, Staphylococcus aureus and Pseudomonas aeruginosa. The anticancer activity of AgNPs was screened against A-431 osteosarcoma cell line by [3-(4, 5-dimetheylthiazol-2)-2, 5 diphenyl tetrazolium bromide] assay and the IC₅₀ value was found to be 91.05 ± 1.53 μg/ml. This trend of eco-friendly stable synthesis of AgNPs could prove a better substitute for the chemical methods and offer greater opportunity to use these nanosilvers in agricultural and biomedical sectors.

Incorporation of nanoparticles into a number of manufacturing products raised the concern of environmental release via deliberate or accidental routes. Here, experiments were performed to examine the effect of copper oxide nanoparticles (CuO NPs), and polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG) impregnated CuO NPs on seed germination and growth of Trigonella foenum-graecum L. as well as on callus induction through tissue culture technique. Seed germination frequency, length, and weight parameters did not inhibit at higher extent by application of NPs; however, copper acetate, PVP, and PEG significantly decreased the values of all parameters. In all the cases, negative effects were observed concentration-dependent. PVP and PEG impregnated CuO were found less toxic for calli fresh and dry weight induced from leaf and stem explants. The 2, 2-diphenyl-1-picrylhydrazyl reagent-free radical scavenging activity, total antioxidative potential, and total reducing power potential along with total flavonoid and phenolic contents are found elevated in root when compared with shoot. Furthermore, impregnation of PVP and PEG on CuO NPs increases the oxidative response. The results conclude that impregnation of organic molecules on nanoparticles does not reduce the toxicity though can be exploited for enhanced production of secondary metabolites for medicinal purposes.

The current investigation involves the green synthesis of copper nanoparticles (CuNPs) from an aqueous plant extract of Moringa oleifera Lam by two methods: (I) time-based approach and (II) heat treatment of aqueous solution. Prepared CuNPs were characterised via Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and transmission EM. The study also reveals the potential bioactivity of the prepared CuNPs. In vitro anti-microbial efficiency of CuNPs was estimated against bacterial and fungal strains by the agar well diffusion method. Anti-oxidant capacity of CuNPs was determined using ferric reducing ability of plasma (FRAP), lipid peroxidation (LPO) and peroxidase assays, while the antiplatelet potential was determined by measuring two haemostatic parameters (PT & APTT assay). The minimum inhibitory concentration was observed at 60 µg/ml against Streptomyces griseus and Aspergillus niger when NPs were prepared by method II. CuNPs prepared by the method I showed higher FRAP and LPO activities, while increased POX activity was found in CuNPs prepared by method II. CuNPs prepared using method I also showed better anti-oxidant and antiplatelet potential. It was observed that M. oleifera-derived CuNPs exhibits strong anti-microbial, anti-oxidant and APTT potential. This indicates potential utilization of green synthesized NPs for various industrial and therapeutic strategies.

The present study reports an eco-friendly and rapid method for the synthesis of core–shell nanoclusters using the modified reverse micelle method. It is a green synthetic method which uses Sesbania grandiflora Linn extract which acts as a reducing and capping agent. It is observed that this method is very fast and convenient and the nanoclusters are formed with 5–10 min of the reaction time without using harsh conditions. The core–shell nanoclusters so prepared were characterised using UV–Vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Further, their effective antibacterial activity towards the gram-positive bacteria Staphylococcus aureus was found to be due to their smaller particle size.

Green synthesis of silver nanoparticles (AgNPs) using Shivlingi (Bryonia laciniosa) seed extract was carried out. Characterisation of synthesised nanoparticles was accomplished through the optical absorption and photoluminescence spectrum, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The XRD analysis further confirmed the size of nanoparticles ∼15 nm. TEM images revealed homogeneous spherical ∼10 nm Bryonia extract capped AgNPs. The biological studies indicated that both Bryonia seed extract and the nanoparticles lack anti-microbial activity; however, the nanoparticles had better cytotoxicity and total antioxidant activity. The Lethal concentration (LC)₅₀ value of water extract and the nanoparticles were found to be 1091 and 592 μg/ml, respectively. The lower LC₅₀ of nanoparticles indicates that it is more cytotoxic than the crude extract. The results indicate that the Bryonia seed is safe to be used as a medicine and the formation of their nanoparticle has further enriched the chemical reactivity, energy absorption and biological mobility.