Antiangiogenic and antiapoptotic effects of green-synthesized zinc oxide nanoparticles using Sargassum muticum algae extraction

Putative mechanism for cancer suppression by PLGA nanoparticles loaded with Peganum harmala smoke extract

Synthesis and investigation of biological activity of Peganum harmala smoke-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles. Peganum harmala smoke-loaded PLGA nanoparticles (PHSE-PNP) were produced by double emulsion solvent evaporation method and characterised by scanning electron microscopy (SEM), dynamic light scattering (DLS), and ζ-potential. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) for toxicity evaluation, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assay for antioxidant power, chorioallantoic membrane (CAM), qPCR, and scratch assay for angiogenesis and mouse cancer model for antitumor effects of PHSE-PNP's were used. PHSE-PNP with a size of 216.33 nm, polydispersity index (PDI): 0.22 and ζ-potential: -25.41 mV inhibited A2780, PC3, A549, HepG2, Mda-mb-231, HT-29 as cancer cells and HUVEC as an normal cells with half-maximal inhibitory concentration (IC₅₀) at about 208.62, 479.05, 1092.6, 1103.9, 1299.21, 3467.5, and <4000 µg/ml, respectively. Also PHSE-PNP inhibited ABTS (IC₅₀: 0.720 mg/ml), DPPH (IC₅₀: 1.36 mg/ml) free radicals and decreased the size of murine tumours (88.3% in 11 days) and suppressed angiogenesis in the CAM and scratch assays. PHSE-PNP can be considered as a potential chemopreventive agent in cancer therapy.

Inhibition of Streptococcus mutans, antioxidant property and cytotoxicity of novel nano-zinc oxide varnish

OBJECTIVE

Zinc is a potent antimicrobial against cariogenic bacteria and effective anti-plaque agent. The present study investigated the efficacy of zinc oxide nanoparticles (ZnO-NP) varnish to inhibit S. mutans growth, biofilm, acid production, and its antioxidant potential and cytotoxicity.

DESIGN

Green synthesized ZnO-NP were characterized using ultraviolet-visible spectroscopy, x-ray diffraction spectroscopy, and transmission electron microscopy. Secondary metabolites were assessed using fourier transform infrared spectroscopy. Anti-oxidant potential was ascertained using 2,2-diphenyl-2-picrylhydrazyl hydrate (DDPH) assay and cytotoxicity of synthesized nanoparticles was evaluated on human liver cancer (Hep G2) and human embryonic kidney 293 (HEK-293T) cell lines.

RESULTS

Synthesized ZnO-NP showed excellent antimicrobial properties against S. mutans, as the minimum inhibitory and bactericidal concentrations were 0.53 μg/mL, and 1.3 μg/mL respectively. ZnO-NP at 0.1 mg/μl concentration had the greatest zone of inhibition (24 mm), followed by 0.05 mg/μl ZnO-NP (23 mm) and 0.05 mg/μl ampicillin (21 mm). Further, 0.1 mg/μl ZnO-NP varnish inhibited 90 % of S. mutans biofilms and reduced 24 h acid production closest to that of baseline and it also exhibited antioxidant capacity in a dose dependent manner (94 % inhibition-100 μg/mL). Biocompatibility of ZnO-NP varnish was evaluated on Hep G2 and HEK-293T cell lines; and the highest concentration of 0.1 mg/μl ZnO-NP used caused very low cytotoxicity to Hep G2 cells and was non-cytotoxic to HEK-293T cells.

CONCLUSIONS

Within the limits of this study, ZnO-NP varnish was effective in inhibiting S. mutans and holds great potential as an effective anticaries agent.

Microbial Nano-Factories: Synthesis and Biomedical Applications

In the recent times, nanomaterials have emerged in the field of biology, medicine, electronics, and agriculture due to their immense applications. Owing to their nanoscale sizes, they present large surface/volume ratio, characteristic structures, and similar dimensions to biomolecules resulting in unique properties for biomedical applications. The chemical and physical methods to synthesize nanoparticles have their own limitations which can be overcome using biological methods for the synthesis. Moreover, through the biogenic synthesis route, the usage of microorganisms has offered a reliable, sustainable, safe, and environmental friendly technique for nanosynthesis. Bacterial, algal, fungal, and yeast cells are known to transport metals from their environment and convert them to elemental nanoparticle forms which are either accumulated or secreted. Additionally, robust nanocarriers have also been developed using viruses. In order to prevent aggregation and promote stabilization of the nanoparticles, capping agents are often secreted during biosynthesis. Microbial nanoparticles find biomedical applications in rapid diagnostics, imaging, biopharmaceuticals, drug delivery systems, antimicrobials, biomaterials for tissue regeneration as well as biosensors. The major challenges in therapeutic applications of microbial nanoparticles include biocompatibility, bioavailability, stability, degradation in the gastro-intestinal tract, and immune response. Thus, the current review article is focused on the microbe-mediated synthesis of various nanoparticles, the different microbial strains explored for such synthesis along with their current and future biomedical applications.

Green Synthesis and Biomedical Applications of ZnO Nanoparticles: Role of PEGylated-ZnO Nanoparticles as Doxorubicin Drug Carrier against MDA-MB-231(TNBC) Cells Line

The present study aimed to develop the synthesis of zinc oxide nanoparticles (ZnO-NPs) using the green method, with Aloe barbadensis leaf extract as a stabilizing and capping agent. In vitro antitumor cytotoxic activity, as well as the surface-functionalization of ZnO-NPs and their drug loading capacity against doxorubicin (DOX) and gemcitabine (GEM) drugs, were also studied. Morphological and structural properties of the produced ZnO-NPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersion X-ray diffraction (EDX), UV-Vis spectrophotometry, Fourier-transform infrared analysis (FTIR), and X-ray diffraction (XRD). The prepared ZnO-NPs had a hexagonal shape and average particle size of 20–40 nm, with an absorption peak at 325 nm. The weight and atomic percentages of zinc (50.58% and 28.13%) and oxygen (26.71% and 60.71%) were also determined by EDAX (energy dispersive x-ray analysis) compositional analysis. The appearance of the FTIR peak at 3420 m–1 confirmed the synthesis of ZnO-NPs. The drug loading efficiency (LE) and loading capacity (LC) of unstabilized and PEGylated ZnO-NPs were determined by doxorubicin (DOX) and gemcitabine (GEM) drugs. DOX had superior LE 65% (650 mg/g) and higher LC 32% (320 mg/g) than GEM LE 30.5% (30 mg/g) and LC 16.25% (162 mg/g) on ZnO-NPs. Similar observation was observed in the case of PEG-ZnO-NPs, where DOX had enhanced LE 68% (680 mg/g) and LC 35% (350) mg/g in contrast to GEM, which had LE and LC values of 35% (350 mg/g) and 19% (190 mg/g), respectively. Therefore, DOX was chosen to encapsulate nanoparticles, along with the untreated nanoparticles, to check their in vitro antiproliferative potential against the triple-negative breast cancer (TNBC) cell line (MDA-MB-231) through the MTT (3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide) assay. This drug delivery strategy implies that the PEGylated biogenically synthesized ZnO-NPs occupy an important position in chemotherapeutic drug loading efficiency and can improve the therapeutic techniques of triple breast cancer.

Microbiologically-Synthesized Nanoparticles and Their Role in Silencing the Biofilm Signaling Cascade

The emergence of bacterial resistance to antibiotics has led to the search for alternate antimicrobial treatment strategies. Engineered nanoparticles (NPs) for efficient penetration into a living system have become more common in the world of health and hygiene. The use of microbial enzymes/proteins as a potential reducing agent for synthesizing NPs has increased rapidly in comparison to physical and chemical methods. It is a fast, environmentally safe, and cost-effective approach. Among the biogenic sources, fungi and bacteria are preferred not only for their ability to produce a higher titer of reductase enzyme to convert the ionic forms into their nano forms, but also for their convenience in cultivating and regulating the size and morphology of the synthesized NPs, which can effectively reduce the cost for large-scale manufacturing. Effective penetration through exopolysaccharides of a biofilm matrix enables the NPs to inhibit the bacterial growth. Biofilm is the consortia of sessile groups of microbial cells that are able to adhere to biotic and abiotic surfaces with the help extracellular polymeric substances and glycocalyx. These biofilms cause various chronic diseases and lead to biofouling on medical devices and implants. The NPs penetrate the biofilm and affect the quorum-sensing gene cascades and thereby hamper the cell-to-cell communication mechanism, which inhibits biofilm synthesis. This review focuses on the microbial nano-techniques that were used to produce various metallic and non-metallic nanoparticles and their "signal jamming effects" to inhibit biofilm formation. Detailed analysis and discussion is given to their interactions with various types of signal molecules and the genes responsible for the development of biofilm.

The Anti-Breast Cancer Effects of Green-Synthesized Zinc Oxide Nanoparticles Using Carob Extracts

BACKGROUND

The use of nanoparticles synthesized by the green method to treat cancer is fairly recent. The aim of this study was to evaluate cytotoxicity, apoptotic and anti-angiogenic effects and the expression of involved genes, of Zinc Oxide Nanoparticles (ZnO-NPs) synthesized with Carob extracts on different human breast cancer cell lines.

METHODS

ZnO-NPs were synthesized using the extracts of Carob and characterized with various analytical techniques. The MCF-7 and MDA-MB231 cells were treated at different times and concentrations of ZnO-NPs. The cytotoxicity, apoptosis, and anti-angiogenic effects were examined using a series of cellular assays. Expression of apoptotic genes (Bax and Bcl2) and anti-angiogenic genes, Vascular Endothelial Growth Factor (VEGF) and its Receptor (VEGF-R) in cancer cells treated with ZnO-NPs were examined with Reverse Transcriptionquantitative Polymerase Chain Reaction (RT-qPCR). The anti-oxidant activities of ZnO-NPs were evaluated by ABTS and DPPH assay.

RESULTS

Exposure of cells to ZnO-NPs resulted in a dose-dependent loss of cell viability. The IC50 values at 24, 48, and 72 hours were 125, 62.5, and 31.2μg/ml, respectively (p<0.001). ZnO-NPs treated cells showed, in fluorescent microscopy, that ZnO-NPs are able to upregulate apoptosis and RT-qPCR revealed the upregulation of Bax (p<0.001) and downregulation of Bcl-2 (p<0.05). ZnO-NPs increased VEGF gene expression while decreasing VEGF-R (p<0.001). The anti-oxidant effects of ZnO-NPs were higher than the control group and were dose-dependent (p<0.001).

CONCLUSION

ZnO-NPs synthetized using Carob extract have the ability to eliminate breast cancer cells and inhibit angiogenesis, therefore, they could be used as an anticancer agent.

Zinc oxide nanocatalyst mediates cadmium and lead toxicity tolerance mechanism by differential regulation of photosynthetic machinery and antioxidant enzymes level in cotton seedlings

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ZnONPs enhanced plant growth and biomass by alleviation of heavy metal toxicity.

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Increased level photosynthetic pigments, MDA and protein contents recorded in cotton leaves in co-presence of ZnONPs.

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The activity of antioxidative enzymes was promoted significantly in the presence of ZnONPs under Cd and Pb induced stress.

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No distinct genomic alterations were recorded in the RAPD banding pattern.

Cadmium (Cd) and Lead (Pb) heavy metal pollution induced toxicity severely affects the plant growth and yield of various agriculutral crops worldwide. The present study discuss the prime role of phycomolecules coated zinc oxide nanoparticles (ZnONPs) application on development of heavy metal tolerance mechanism in cotton (Gossypium hirsutum L.) seedlings better than exposed to Cd and Pb treatments alone. Co-exposure of ZnONPs along with heavy metal treatments significantly promoted the shoot, and root growth as well as biomass compared to control, while it was down-regulated in Cd and Pb exposed seedlings. The intervention of ZnONPs had up-regulated the level of chlorophyll a, b and carotenoid contents in leaves grown under Cd and Pb treatments than the untreated control. Similarly, the level of total soluble protein and malondialdehyde (MDA-lipid peroxidation) contents was significantly increased in the co-presence of ZnONPs along with Cd and Pb treatments over their respective control. Accumulation of antioxidant defense enzymes viz., superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APX) was up-regulated significantly in seedlings upon co-exposure of ZnONPs with Cd and Pb treatments. Random amplified polymorphic DNA (RAPD) fingerprinting analysis exhibited no genomic changes/alterations in seedlings by co-existence of ZnONPs with heavy metals. Overall, the present results indicate that the addition of ZnONPs with Cd and Pb ion exposure protects cotton seedlings by alleviating heavy metal induced phytotoxicity and promoted physiochemical characteristics via differential regulation of photosynthetic machinery as well as antioxidative defense mechanisms in cotton seedlings. Results strongly suggest that phycomolecule coated ZnO nanoparticles could be effectively used as nanofertilizer to cultivate agronomically important crops in heavy metal polluted soil in the future.

Green Synthesis of Zinc Oxide Nanoparticles: Fortification for Rice Grain Yield and Nutrients Uptake Enhancement

Applications of metal oxide nanoparticles in the agriculture sector are being extensively included as the materials are considered superior. In the present work, zinc oxide nanoparticle (ZnO NPs), with a developing fertilizer, is applied in the fortification of rice grain yield and nutrient uptake enhancement. To evaluate the role of ZnO NP, two field experiments were conducted during the 2018 and 2019 seasons. ZnO NPs were small, nearly spherical, and their sizes equal to 31.4 nm, as proved via the dynamic light scattering technique. ZnO NPs were applied as a fertilizer in different concentrations, varying between 20 and 60 mg/L as a foliar spray. The mixture of ZnSO₄ and ZnO NP₄₀ ameliorated yield component and nutrients (N, K, and Zn) uptake was enhanced compared to traditional ZnSO₄ treatment. Nevertheless, the uptake of the phosphorous element (P) was adversely affected by the treatment of ZnO NPs. Thus, treatment via utilizing ZnO NPs as a foliar with a very small amount (40 ppm) with of basal ZnSO₄ led to a good improvement in agronomic and physiological features; eventually, higher yield and nutrient-enriched rice grain were obtained.

Unravelling the human triple negative breast cancer suppressive activity of biocompatible zinc oxide nanostructures influenced by Vateria indica (L.) fruit phytochemicals

The present study delineates the biosynthesis of ZnOVI nanostructures by using aqueous fruit extract of V. indica. The study has disclosed the role of V. indica fruit extract as both reducing and capping agents, ushering the formation of ZnOVI nanostructures with distinct morphologies. The formation of ZnOVI nanostructures was corroborated by FT-IR and UV-visible spectroscopy which was further substantiated by the elemental composition study through EDS spectroscopy. The nanostructures were also investigated by Rietveld refinement of PXRD data, FE-SEM, and BET analysis. The morphology, size, and surface area were found to be precursor stoichiometry dependent. The in-vitro cytotoxicity study of ZnOVI nanostructures carried out on MDA-MB468 human triple-negative breast cancer (TNBC) cells has revealed their potential cytotoxicity (91.18 ± 1.98). MTT assay performed on the NIH3T3 mouse fibroblast cells has unfolded the non-toxic nature of ZnOVI nanostructures. Additionally, the results of the AO-EB dual staining assay indicated early apoptosis in TNBC cells by displaying greenish yellow-fluorescence in the nuclei. Reactive oxygen species (ROS) measurement study has confirmed the elevated intracellular levels of ROS, supporting the oxidative-stress induced cytotoxicity in ZnOVI nanostructures treated TNBC cells. Furthermore, the haemocompatibility of ZnOVI nanostructures was evaluated using human erythrocytes. Thus, the obtained results have shown greater potential in the anticancer activity of bio-fabricated ZnOVI nanostructures.

Green Synthesis of Zinc Oxide Nanoparticles (ZnO-NPs) Using Arthrospira platensis (Class: Cyanophyceae) and Evaluation of their Biomedical Activities

In this study, zinc oxide nanoparticles (ZnO-NPs) were successfully fabricated through the harnessing of metabolites present in the cell filtrate of a newly isolated and identified microalga Arthrospira platensis (Class: Cyanophyceae). The formed ZnO-NPs were characterized by UV-Vis spectroscopy, Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Data showed the efficacy of cyanobacterial metabolites in fabricating spherical, crystallographic ZnO-NPs with a size ≈30.0 to 55.0 nm at a wavelength of 370 nm. Moreover, FT-IR analysis showed varied absorption peaks related to nanoparticle formation. XPS analysis confirms the presence of Zn(II)O at different varied bending energies. Data analyses exhibit that the activities of biosynthesized ZnO-NPs were dose-dependent. Their application as an antimicrobial agent was examined and formed clear zones, 24.1 ± 0.3, 21.1 ± 0.06, 19.1 ± 0.3, 19.9 ± 0.1, and 21.6 ± 0.6 mm, at 200 ppm against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans, respectively, and these activities were reduced as the NPs concentration decreased. The minimum inhibitory concentration (MIC) values were determined as 50 ppm for S. aureus, 25 ppm for P. aeruginosa, and 12.5 ppm for B. subtilis, E. coli, and C. albicans. More interestingly, ZnO-NPs exhibit high in vitro cytotoxic efficacy against cancerous (Caco-2) (IC50 = 9.95 ppm) as compared with normal (WI38) cell line (IC50 = 53.34 ppm).

Green Synthesis of Metallic Nanoparticles and Their Prospective Biotechnological Applications: an Overview

The green synthesis of nanoparticles (NPs) using living cells is a promising and novelty tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs; however, biological methods are preferred due to its eco-friendly, clean, safe, cost-effective, easy, and effective sources for high productivity and purity. High pressure or temperature is not required for the green synthesis of NPs, and the use of toxic and hazardous substances and the addition of external reducing, stabilizing, or capping agents are avoided. Intra- or extracellular biosynthesis of NPs can be achieved by numerous biological entities including bacteria, fungi, yeast, algae, actinomycetes, and plant extracts. Recently, numerous methods are used to increase the productivity of nanoparticles with variable size, shape, and stability. The different mechanical, optical, magnetic, and chemical properties of NPs have been related to their shape, size, surface charge, and surface area. Detection and characterization of biosynthesized NPs are conducted using different techniques such as UV-vis spectroscopy, FT-IR, TEM, SEM, AFM, DLS, XRD, zeta potential analyses, etc. NPs synthesized by the green approach can be incorporated into different biotechnological fields as antimicrobial, antitumor, and antioxidant agents; as a control for phytopathogens; and as bioremediative factors, and they are also used in the food and textile industries, in smart agriculture, and in wastewater treatment. This review will address biological entities that can be used for the green synthesis of NPs and their prospects for biotechnological applications.

PLGA-Based Nano-Encapsulation of Trachyspermum Ammi Seed Essential Oil (TSEO-PNP) as a Safe, Natural, Efficient, Anticancer Compound in Human HT-29 Colon Cancer Cell Line

Colorectal cancer is a lethal and commonly diagnosed cancer worldwide. To halt its burden more efficient targeted strategies are needed. Trachyspermum ammi seed essential oil (TSEO) contains several anticancer phytochemicals that maybe more effective via PLGA-based nano-encapsulation. TSEO-PNP nanoparticles were synthesized utilizing evaporation and ultra-sonication-based emulsification methods. Their size, morphology, and stability were defined by DLS, SEM, and surface zeta-potential data, respectively. The TSEO-PNP antioxidant apoptotic, cytotoxic, and antiangiogenic impacts on both cell lines (HT-29 and HUVEC) were studied by FRAP/ABTS, Q-PCR, MTT, and CAM assays, respectively. Moreover, further confirmatory measurements such as AO/EB fluorescent staining and flow cytometry analysis were performed to verify apoptosis. Stable (-32.42 mV) 206.21-nm TSEO-PNP induced apoptosis in the HT-29 cells. Apoptosis was confirmed by significant overexpression of apoptotic genes (Cas-9 and BAX), down-regulation of the anti-apoptotic (BCL-2) gene, fluorescent AO/EB staining, and flow cytometry data following increased TSEO-PNP treatment doses. TSEO-PNP exhibited a meaningful dose- and time-dependent cancer-specific cytotoxic impact on HT-29 cells. The TSEO-PNP has three main anticancer activities on HT-29 colon cancer cells including oxidant reduction, apoptosis induction, and angiogenesis suppression.

Phytosynthesized nanoparticles as a potential cancer therapeutic agent

Plants are the well-known sources for the hyper-accumulation and reduction of metallic ions. Analysis of various plant extracts has justified the presence of different types of phytochemicals that possess the stabilization and reduction functionalities of precursors to form nanoparticles. Such characteristics make plants as an attractive source for synthesizing eco-friendly nanoparticles (NPs) with potentially less toxicity to the body. Recently, phytosynthesized nanoparticles have been explored for targeted inhibition and diagnosis of cancer cells without affecting non-cancerous healthy cells. The aim of this review is to discuss the characteristic performance of NPs synthesized from various plant sources for the diagnosis and inhibition of cancer. The mode of action of phytosynthesized nanoparticles for anti-cancer applications are also discussed.

The Chorioallantoic Membrane Assay in Nanotoxicological Research-An Alternative for In Vivo Experimentation

Nanomaterials unveil many applicational possibilities for technical and medical purposes, which range from imaging techniques to the use as drug carriers. Prior to any human application, analysis of undesired effects and characterization of their toxicological profile is mandatory. To address this topic, animal models, and rodent models in particular, are most frequently used. However, as the reproducibility and transferability to the human organism of animal experimental data is increasingly questioned and the awareness of animal welfare in society increases at the same time, methodological alternatives are urgently required. The chorioallantoic membrane (CAM) assay is an increasingly popular in ovo experimental organism suitable for replacement of rodent experimentation. In this review, we outline several application fields for the CAM assay in the field of nanotoxicology. Furthermore, analytical methods applicable with this model were evaluated in detail. We further discuss ethical, financial, and bureaucratic aspects and benchmark the assay with other established in vivo models such as rodents.

The Apoptotic, Cytotoxic, and Antiangiogenic Impact of Linum usitatissimum Seed Essential Oil Nanoemulsions on the Human Ovarian Cancer Cell Line A2780

BACKGROUND

Linum usitatissimum seed essential oil (LSEO) has been used to reduce the risk of prostate and colon cancer. In this study, we optimized the bio-accessibility and bio-compatibility of LSEO to evaluate its cytotoxic, apoptotic and anti-angiogenic impact on the human ovarian cancer cell line A2780.

METHOD

We produced LSEO nanoemulsions (LSEO-NEs) utilizing the ultrasound-based technique and the size, its droplets' morphology and stability were characterized. LSEO-NE cytotoxicity was studied by estimating the viability of A2780 human ovarian cancer cell and normal human foreskin fibroblasts (HFFS). Their apoptotic activity was evaluated measuring the Caspase-3, 8 and nine gene expression. Finally, its anti-angiogenic potential was measured applying Chick Chorioallantoic Membrane (CAM) assay.

RESULTS

A significant dose-dependent cytotoxic impact of LSEO-NE was detected in the A2780 cells and not in HFF cellsThe apoptotic genes expression profile confirmed the A2780 cell apoptosis death. Moreover, the reduction in length and number of blood vessels in the CAM assay demonstrated the anti-angiogenic activity of LSEO-NE.

CONCLUSION

The cancer cell-selective cytotoxicity apoptosis, and anti-angiogenic effects of LSEO-NE indicate its potential as a novel anticancer compound. However, further cell lines have to be analyzed in case of its potential anticancer impacts on human ovarian cancer cells.

Zinc oxide nanoparticles inhibit bacterial biofilm formation via altering cell membrane permeability

In the current scenario nanoparticles (NPs) have gained a breathtaking impetus due to their multidimensional applications in varied fields. In the present effort, biogenic synthesis of Zinc Oxide nanoparticles (ZnO NPs) was carried out using aqueous extract of dried powder of Emblica officinalis (Amla). Physicochemical characterization of nanoparticles was carried out via UV-Visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) wherein the particles were found to be quasi spherical and with a size ranging between 3 and 11 nm. The ZnO nanoparticles exhibited significant antibacterial activity against bacteria as Streptococcus pyogenes MTCC 442, Bacillus cereus MTCC 1272, Escherichia coli MTCC 1687 and Pseudomonas aeruginosa MTCC 4673. The nanoparticles displayed high anti-biofilm activity toward all the bacterial strains, when tested against three different base materials viz. glass, plastic and metal (Aluminum). Further, the nanoparticle treatment of bacterial cells caused changes in their cell membrane permeability, leading to leakage of nucleic acid from the bacterial cells, thereby defining it as the most probable mechanism for their anti-biofilm potential.

Enhancing ZnO-NP Antibacterial and Osteogenesis Properties in Orthopedic Applications: A Review

Prosthesis-associated infections and aseptic loosening are major causes of implant failure. There is an urgent need to improve the antibacterial ability and osseointegration of orthopedic implants. Zinc oxide nanoparticles (ZnO-NPs) are a common type of zinc-containing metal oxide nanoparticles that have been widely studied in many fields, such as food packaging, pollution treatment, and biomedicine. The ZnO-NPs have low toxicity and good biological functions, as well as antibacterial, anticancer, and osteogenic capabilities. Furthermore, ZnO-NPs can be easily obtained through various methods. Among them, green preparation methods can improve the bioactivity of ZnO-NPs and strengthen their potential application in the biological field. This review discusses the antibacterial abilities of ZnO-NPs, including mechanisms and influencing factors. The toxicity and shortcomings of anticancer applications are summarized. Furthermore, osteogenic mechanisms and synergy with other materials are introduced. Green preparation methods are also briefly reviewed.

Uniting Drug and Delivery: Metal Oxide Hybrid Nanotherapeutics for Skin Wound Care

Wound care and soft tissue repair have been a major human concern for millennia. Despite considerable advancements in standards of living and medical abilities, difficult-to-heal wounds remain a major burden for patients, clinicians and the healthcare system alike. Due to an aging population, the rise in chronic diseases such as vascular disease and diabetes, and the increased incidence of antibiotic resistance, the problem is set to worsen. The global wound care market is constantly evolving and expanding, and has yielded a plethora of potential solutions to treat poorly healing wounds. In ancient times, before such a market existed, metals and their ions were frequently used in wound care. In combination with plant extracts, they were used to accelerate the healing of burns, cuts and combat wounds. With the rise of organic chemistry and small molecule drugs and ointments, researchers lost their interest in inorganic materials. Only recently, the advent of nano-engineering has given us a toolbox to develop inorganic materials on a length-scale that is relevant to wound healing processes. The robustness of synthesis, as well as the stability and versatility of inorganic nanotherapeutics gives them potential advantages over small molecule drugs. Both bottom-up and top-down approaches have yielded functional inorganic nanomaterials, some of which unite the wound healing properties of two or more materials. Furthermore, these nanomaterials do not only serve as the active agent, but also as the delivery vehicle, and sometimes as a scaffold. This review article provides an overview of inorganic hybrid nanotherapeutics with promising properties for the wound care field. These therapeutics include combinations of different metals, metal oxides and metal ions. Their production, mechanism of action and applicability will be discussed in comparison to conventional wound healing products.

Natural Metallic Nanoparticles for Application in Nano-Oncology

Here, the various types of naturally synthesized metallic nanoparticles, which are essentially composed of Ce, Ag, Au, Pt, Pd, Cu, Ni, Se, Fe, or their oxides, are presented, based on a literature analysis. The synthesis methods used to obtain them most often involve the reduction of metallic ions by biological materials or organisms, i.e., essentially plant extracts, yeasts, fungus, and bacteria. The anti-tumor activity of these nanoparticles has been demonstrated on different cancer lines. They rely on various mechanisms of action, such as the release of chemotherapeutic drugs under a pH variation, nanoparticle excitation by radiation, or apoptotic tumor cell death. Among these natural metallic nanoparticles, one type, which consists of iron oxide nanoparticles produced by magnetotactic bacteria called magnetosomes, has been purified to remove endotoxins and abide by pharmacological regulations. It has been tested in vivo for anti-tumor efficacy. For that, purified and stabilized magnetosomes were injected in intracranial mouse glioblastoma tumors and repeatedly heated under the application of an alternating magnetic field, leading to the full disappearance of these tumors. As a whole, the results presented in the literature form a strong basis for pursuing the efforts towards the use of natural metallic nanoparticles for cancer treatment first pre-clinically and then clinically.

Citrus lemon essential oil nanoemulsion (CLEO-NE), a safe cell-depended apoptosis inducer in human A549 lung cancer cells with anti-angiogenic activity

Aims: Citrus lemon essential oil (CLEO) has been introduced as a strong antioxidant mixture. However, it is not efficient enough due to its hydrophobic nature. Nanoemulsions improve the drugs' bio-compatibility in aqueous conditions.Methods: The CLEO nanoemulsion (CLEO-NE) was formulated by ultrasound-based-emulsification and they were characterised. The anti-angiogenic and antioxidant activities were studied by the chicken chorioallantoic membrane (CAM) and antioxidant (ABTS and DPPH) assays, respectively. Finally, the apoptotic property of CLEO-NE on both HFF and A549 was evaluated by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay and real time-PCR (measuring Cas-3 gene expression).Results: The 30.2-nm CLEO-NE droplets significantly increased Cas-3 in A549 cells and decreased angiogenesis in chick embryo chorioallantoic membrane (p < 0.01).Conclusion: In conclusion, CLEO-NE has the potential to be used as a safe cell-depended anticancer agent for human lung cancer. However, further genes and cell lines have to be studied to clarify its targeted-anticancer activity.

Nanoparticles characterization using the CAM assay

The current chapter highlights the use of chorioallantoic membrane (CAM) of fertilized chicken egg for the characterization of nanoparticles applied in cancer nanomedicine. The CAM assay represents a promising alternative to mouse models in term of costs, ease of use, rapidity and ethical issues in particular for the screening of nanoformulations. Hence, the features of nanoparticles including blood retention, biocompatibility, active targeting or tumor accumulation, angiogenic activity, drug delivery and tumor elimination might be simply evaluated via the CAM model. In particular, in this model, embryo organs and morphology, CAM vasculature and blood cells, transplanted tumors on CAM were typically monitored and used for the evaluation of the nanomaterials. With the above advantages, the CAM assay, as highly valuable in vivo model, could be used regularly in pharmaceutical industries.

Algae-based metallic nanoparticles: Synthesis, characterization and applications

Nanomaterials (NMs) tailored via conventional physicochemical routes play havoc with the environment that has led to the evolution of competent green routes for the actualization of a circular economy on an industrial-scale. Algae belonging to the class Cyanophyceae, Chlorophyceae, Phaeophyceae and Rhodophyceae have been harnessed as nano-machineries through intracellular and extracellular synthesis of gold (Au), silver (Ag) and several other metallic nanoparticles. Algae are an appealing platform for the production of diverse NMs, primarily due to the presence of bioactive compounds such as pigments and antioxidants in their cell extracts that act as biocompatible reductants. Chlorella spp. and Sargassum spp. have been extensively explored for the synthesis of nanoparticles having antimicrobial properties, which can potentially substitute conventional antibiotics. Characterization of nanoparticles (NPs) synthesised from algae has been done using advanced spectroscopic, diffractographic and microscopic techniques such as UV-Vis FT-IR, DLS, XPS, XRD, SEM, TEM, AFM, HR-TEM, and EDAX. The present paper reviews the information available on algae-mediated biosynthesis of various NPs, their characterization and applications in different domains.

A review on the biosynthesis of metal and metal salt nanoparticles by microbes

Metal nanoparticles have received great attention from researchers across the world because of a plethora of applications in agriculture and the biomedical field as antioxidants and antimicrobial compounds. Over the past few years, green nanotechnology has emerged as a significant approach for the synthesis and fabrication of metal nanoparticles. This green route employs various reducing and stabilizing agents from biological resources for the synthesis of nanoparticles. The present article aims to review the progress made in recent years on nanoparticle biosynthesis by microbes. These microbial resources include bacteria, fungi, yeast, algae and viruses. This review mainly focuses on the biosynthesis of the most commonly studied metal and metal salt nanoparticles such as silver, gold, platinum, palladium, copper, cadmium, titanium oxide, zinc oxide and cadmium sulphide. These nanoparticles can be used in pharmaceutical products as antimicrobial and anti-biofilm agents, targeted delivery of anticancer drugs, water electrolysis, waste water treatment, biosensors, biocatalysis, crop protection against pathogens, degradation of dyes etc. This review will discuss in detail various microbial modes of nanoparticles synthesis and the mechanism of their synthesis by various bioreducing agents such as enzymes, peptides, proteins, electron shuttle quinones and exopolysaccharides. A thorough understanding of the molecular mechanism of biosynthesis is the need of the hour to develop a technology for large scale production of bio-mediated nanoparticles. The present review also discusses the advantages of various microbial approaches in nanoparticles synthesis and lacuna involved in such processes. This review also highlights the recent milestones achieved on large scale production and future perspectives of nanoparticles.

Carpogenic ZnO nanoparticles: amplified nanophotocatalytic and antimicrobial action

This investigation has for the first time utilised environmental resource Prunus cerasifera seed extract phytochemicals for the green synthesis of carpogenic ZnO nanoparticles (NPs). Spherical morphology and size range of 56.57-107.70 nm at variable calcination temperatures without the use of any external reducing agent was obtained. The synthesised NPs exhibited hexagonal wurtzite geometry with an average crystal size 5.62 nm and a band gap of 3.4 eV. Carpogenic NPs were investigated for optical, compositional, morphological, and phytochemical make up via ultraviolet spectroscopy (UV-Vis), Fourier transform infrared analysis, X-ray powder diffraction, scanning electron microscopy, and gas chromatography and mass spectrometry. Carpogenic NPs degraded methyl red up to 83% with pseudo-first-order degradation kinetics (R2 = 0.88) in 18 min signifying their remediation role in environment in conformity with all principles of green chemistry. Photocatalytic assays were performed in direct solar irradiance. Nine pathogens of biomedical and agricultural significance having multi-drug resistance were inhibited in vitro via the Kirby-Bauer disc diffusion assay. The enhanced photocatalytic and antimicrobial inhibition not only makes carpogenic ZnO NPs a future photo-degradative candidate for environmental remediation but also a nanofertiliser, nanofungicide, and nanobactericide synthesised via bioinspired, biomimetic, green, and unprecedented route.

Heavy metal resistance in algae and its application for metal nanoparticle synthesis

The ungenerous release of metals from different industrial, agricultural, and anthropogenic sources has resulted in heavy metal pollution. Metals with a density larger than 5 g cm^-3 have been termed as heavy metals and have been stated to be potentially toxic to human and animals. Algae are known to be pioneer organisms with the potential to grow under extreme conditions including heavy metal-polluted sites. They have evolved efficient defense strategies to combat the toxic effects exerted by heavy metal ions. Most of the algal strains are reported to accumulate elevated metal ion concentration in cellular organelles. With respect to that, this review focuses on understanding the various strategies used by algal system for heavy metal resistance. Additionally, the application of this metal resistance in biosynthesis of metal nanoparticles and metal oxide nanoparticles has been investigated in details. We thereby conclude that algae serve as an excellent system for understanding metal uptake and accumulation. This thereby assists in the design and development of low-cost approaches for large-scale synthesis of nanoparticles and bioremediation approach, providing ample opportunities for future work.

Biogenesis of ZnO nanoparticles using Pandanus odorifer leaf extract: anticancer and antimicrobial activities

The continuously increasing incidence rates of cancer and infectious diseases are open threats to the sustainable survival of animals and humans.

Biosynthesis of Metal Nanoparticles via Microbial Enzymes: A Mechanistic Approach

During the last decade, metal nanoparticles (MtNPs) have gained immense popularity due to their characteristic physicochemical properties, as well as containing antimicrobial, anti-cancer, catalyzing, optical, electronic and magnetic properties. Primarily, these MtNPs have been synthesized through different physical and chemical methods. However, these conventional methods have various drawbacks, such as high energy consumption, high cost and the involvement of toxic chemical substances. Microbial flora has provided an alternative platform for the biological synthesis of MtNPs in an eco-friendly and cost effective way. In this article we have focused on various microorganisms used for the synthesis of different MtNPs. We also have elaborated on the intracellular and extracellular mechanisms of MtNP synthesis in microorganisms, and have highlighted their advantages along with their challenges. Moreover, due to several advantages over chemically synthesized nanoparticles, the microbial MtNPs, with their exclusive and dynamic characteristics, can be used in different sectors like the agriculture, medicine, cosmetics and biotechnology industries in the near future.