Eco friendly synthesis and characterization of zinc oxide nanoparticles from Aegle marmelos and its cytotoxicity effects on MCF-7 cell lines

An attempt was made to synthesize zinc oxide gum white nanoparticles (ZnO-GWNPs) by the greenway approach using Aegle marmelos (Bael fruit) juice extract as a capping and reducing agent. Synthesis of ZnO-GWNPs by greener approach is safer, more economical, more energy-efficient, eco-friendlier, and less toxic than chemically synthesized counterparts. The optical properties of the ZnO-GWNPs were ascertained through UV-Vis spectroscopy, Fourier Transform-Infrared (FT-IR), X-ray diffraction (XRD), High-resolution transmittance electron microscopy (HRTEM). A characteristic absorption peak at 385nm confirmed the presence of ZnO-GWNP using UV-Vis spectroscopy. FTIR spectrum revealed that the characteristic absorption peak of the Zn-O bond was observed at 467 cm-1. The XRD result for the ZnO showed the tendency of the three most intense diffraction peaks. The average crystallite size ZnO NPs at scattering angle (2θ) 22.89 and 32.15 was 39.14 and 26.08 nm and it showed the presence of miller indices of (100), (002), (101), (102) respectively. The EDX spectrum gave strong signals for zinc and oxygen indicating the occurrence of the nanoparticles in their oxide form rather than the pure zinc form. The SEM image showed the surface morphology of ZnO-GW NPs and the HR-TEM image showed the crystalline nature of ZnO-GW NPs. Cytotoxicity study of ZnO-GW NPs was determined against MCF-7 cell lines and the IC50 values were found to be 40 µg/mL and 60 µg/mL at 24 h and 48 h respectively.

Synthesis and characterization of PCU@C-Ag/AgCl nanoparticles as an antimicrobial material for respiratory tract infection

The pregnant cow urine (PCU) is an active source of antimicrobial agents that is used for fabricating chitosan coated Ag/AgCl nanoparticles (NPs) in the present study. These PCU@C-Ag/AgCl NPs were physicochemically characterized and evaluated for antimicrobial activity against selected respiratory tract infection (RTI) pathogens. The absorption band around 420 nm in UV-Visible spectrum indicated the presence of Ag NPs. The spherical shape of NPs was observed using TEM. Also, the crystalline structure was confirmed using the XRD pattern. The PCU@C-Ag/AgCl NPs showed strong antimicrobial activity against all tested RTI pathogens. In addition, FESEM analysis showed morphological changes in RTI bacterial pathogens. Thereby, PCU@C-Ag/AgCl NPs may be used as an antimicrobial material to treat RTIs in near future at clinical level.

Green synthesis of silver nanoparticles and evaluation of their anti-bacterial activities: use of Aloe barbadensis miller and Ocimum tenuiflorum leaf extracts

The presence of various phytochemicals makes the leaf extract-based green synthesis advantageous to other conventional methods, as it facilitates the production of non-toxic by-product. In the present study, leaf extracts from two different plants: Aloe barbadensis miller and Ocimum tenuiflorum, were used to synthesise Ag nanoparticles. The absorbance at 419-432 nm from UV-visible spectroscopy indicates the formation of Ag in the synthesised samples. The effect of precursors’ concentration on the stability, size and shape of the synthesised samples has also been investigated at constant heating temperature, stirring time, and the pH of the solution. The TEM results showed that all the synthesised samples of nanoparticles demonstrated stability with a size range of 7-70 and 9-48 nm with Aloe barbadensis miller and Ocimum tenuiflorum leaf extracts, respectively. The formation of smaller Ag nanoparticles due to utilisation of different precursor concentration and leaf extracts was also explained. The synthesised samples’ anti-bacterial activity was examined against the pathogens, Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. In general, the green synthesis approach established a prospective for developing highly stable Ag nanoparticles with rigid particle shape/size distribution from different leaf extracts for the development of better anti-bacterial agents.

Nanofabrication route to achieve sustainable production of next generation defect-free graphene: analysis and characterisation

In the past two decades, graphene has been one of the most studied materials due to its exceptional properties. The scalable route to cost-effective manufacture defect-free graphene has continued to remain a technical challenge. Intrinsically defect-free graphene changes its properties dramatically, and it is a challenging task to control the defects in graphene production using scaled-down subtractive manufacturing techniques. In this work, the exfoliation of graphite was investigated as a sustainable low-cost graphene manufacturing technique. The study made use of a simple domestic appliance e.g., a kitchen blender to churn graphene in wet conditions by mixing with N-Methyl-2-pyrrolidone (NMP). It was found that the centrifugal force-induced turbulent flow caused by the rotating blades exfoliates graphite flakes to form graphene. The technique is endowed with a high yield of defect-free graphene (0.3 g/h) and was deemed suitable to remove 10% fluoride content from the water and color absorption from fizzy drinks.

Synthesis, characterization and anticancer activities of silver nanoparticles from the leaves of Datura stramonium L.

In recent years, a wide range of studies has pointed out the role of nanoparticles as reservoirs of therapeutics for several diseases, including cancer. Nowadays, cancer research is focused on the development of novel treatment approaches to fight this dreadful disorder. Based on the evidential research and applications of nanoparticles, it is expected that green synthesized nanoparticles may show a prominent role, especially in the biomedical field. The present work is centered on the preparation and characterization of silver nanoparticles (Ag-NPs) from the aqueous (AQ) extract and non-alkaloidal (NA) fraction of Datura stramonium leaves and to evaluate their anticancer potential against mammalian cell lines. The biogenic Ag-NPs are characterized by UV-vis spectra, FTIR DLS, UV-Vis, SEM, and TEM. SEM and TEM analysis reveals the spherical morphology of NPs. The Ag-NPs exhibit cytotoxicity against various mammalian cell lines (A549, HCT-116, PANC-1, SHSY5Y, and U87), which indicate that the AQ and NA based NPs are highly potent to cause cancer cell death. To the best of our knowledge, the present report, for the first time, describes the green synthesis of Ag-NPs from the NA fraction of the D. stramonium and provides pieces of evidence for its anticancer potential.

pH-responsive cisplatin-loaded niosomes: synthesis, characterization, cytotoxicity study and interaction analyses by simulation methodology

Cisplatin (Cis) is an effective cytotoxic agent, but its administration has been challenged by kidney problems, reduced immunity system, chronic neurotoxicity, and hemorrhage. To address these issues, pH-responsive non-ionic surfactant vesicles (niosomes) by Span 60 and Tween 60 derivatized by cholesteryl hemisuccinate (CHEMS), a pH-responsive agent, and Ergosterol (helper lipid), were developed for the first time to deliver Cis. The drug was encapsulated in the niosomes with a high encapsulation efficiency of 89%. This system provided a responsive release of Cis in pH 5.4 and 7.4, thereby improving its targeted anticancer drug delivery. The noisome bilayer model was studied by molecular dynamic simulation containing Tween 60, Span 60, Ergosterol, and Cis molecules to understand the interactions between the loaded drug and noisome constituents. We found that the platinum and chlorine atoms in Cis are critical factors in distributing the drug between water and bilayer surface. Finally, the lethal effect of niosomal Cis was investigated on the MCF7 breast cancer cell line using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Results from morphology monitoring and cytotoxic assessments suggested a better cell-killing effect for niosomal Cis than standard Cis. Together, the synthesis of stimuli-responsive niosomes could represent a promising delivery strategy for anticancer drugs.

Development of mucoadhesive thiomeric chitosan nanoparticles for the targeted ocular delivery of vancomycin against Staphylococcus aureus resistant strains

This study aims to formulate mucoadhesive vancomycin loaded thiolated chitosan (TCS) nanoparticles. These nanoparticles are mucoadhesive and enhance the retention of the drug at the ocular site. For this purpose, TCS loaded vancomycin nanoparticles were prepared by the ion-gelation method and were characterized for their size, shape, polydispersity index, mucoadhesion, cellular uptake and anti-inflammatory activity. The average size of the synthesized nanoparticles was found to be 288 nm with positive zeta potential. Moreover, 85% vancomycin was successfully encapsulated in TCS nanoparticles by using this method. A 2-fold increase in mucoadhesion was found as compared to non-thiolated vancomycin formulation (p < 0.05). Zone of inhibition of vancomycin loaded TCS was also significantly improved compared to non-thiolated chitosan nanoparticles and vancomycin alone. In-vivo anti-inflammatory evaluation via histopathology resulted in ocular healing. Based on the results, it is inferred that TCS nanoparticles are a promising drug delivery carrier system for ocular delivery of vancomycin.

Fabrication of Cell-Derived Biomimetic Drug Delivery System

Functional biomaterials that are capable of effectively carrying therapeutic agents and specifically delivering therapeutics to pathological sites have been widely investigated over decades. Recently, cellular carriers and cell derivative-based bio-hybrid delivery systems have drawn extensive attention as a promising branch of therapeutic delivery systems, owing to their low immunogenicity and intriguing biomimetic capabilities. Various approaches for the fabrication of these biomimetic carriers have been developed, and some products have already been commercialized as well. In this review, we summarized various processing methods for engineering cell-derived biomimetic drug delivery systems, and discussed their future outlooks.

Recent Advances in Novel DNA Guiding Nanofabrication and Nanotechnology

DNA as life’s genetic material has been widely investigated around the world. In recent years, with the fiery researches on nanomaterials, it also plays an important role in the development of material science due to its extraordinary molecular recognition capability and prominent structural features. In this mini review, we mainly overview the recent progresses of DNA guiding self-assembled nanostructures and nanofabrication. Typical DNA tile-based assembly and DNA origami nanotechnologies are presented, utilizing the recent 3D topology methods to fabricate multidimensional structures with unique properties. Then the site-specific nanomaterials synthesis and nano-DNA recognition on different DNA scaffolds/templates are demonstrated with excellent addressability, biocompatibility and structural programmability. Various nanomaterials, such as metals, carbon family materials, quantum dots, metal-organic frameworks, and DNA-based liquid crystals are briefly summarized. Finally, the present limitation and future promising development directions are discussed in conclusion and perspective. We wish this review would provide useful information toward the broader scientific interests in DNA nanotechnology.

Bio-surface engineering with DNA scaffolds for theranostic applications

Biosensor design is important to bioanalysis yet challenged by the restricted target accessibility at the biomolecule-surface (bio-surface). The last two decades have witnessed the appearance of various “art-like” DNA nanostructures in one, two, or three dimensions, and DNA nanostructures have attracted tremendous attention for applications in diagnosis and therapy due to their unique properties (e.g., mechanical flexibility, programmable control over their shape and size, easy and high-yield preparation, precise spatial addressability and biocompatibility). DNA nanotechnology is capable of providing an effective approach to control the surface functionality, thereby increasing the molecular recognition ability at the biosurface. Herein, we present a critical review of recent progress in the development of DNA nanostructures in one, two and three dimensions and highlight their biological applications including diagnostics and therapeutics. We hope that this review provides a guideline for bio-surface engineering with DNA nanostructures.