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Abstract Core-shell Fe 3 O 4 /Au nanostructures were constructed using an advanced method of two-step synthesis from Juglans regia (walnut) green husk extract. Several complementary methods were applied to investigate structural and magnetic properties of the samples. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), electron diffraction, optical, thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM) were used for nanoparticle characterizations. As shown by HR-TEM, the mean diameter of core-shell Fe 3 O 4 /Au nanoparticles synthesized using co-precipitation method was 6.08 ± 1.06 nm. This study shows that the physical and structural properties of core-shell Fe 3 O 4 /Au nanoparticles possess intrinsic properties of gold and magnetite. VSM revealed that the core-shell Fe 3 O 4 /Au have high saturation magnetization and low coercivity due to the magnetic properties. The core-shell nanoparticles show the inhibitory concentration (IC) 50 of 235 μg/ml against a colorectal cancer cell line, HT-29. When tested against non-cancer cells, IC 50 was not achieved even up to 500 μg/ml. This study highlights the magnetic properties and anticancer action of core-shell Fe 3 O 4 /Au nanoparticles. This compound can be ideal candidate for cancer treatment and other biomedical applications. Graphical abstract Unlabelled Image Highlights • Gold ion was coated on surface of iron oxide using Juglans regia green husk (walnut) that acts as size controlled. • Green synthesized core shell nanoparticles were successfully was carried out by autoclaved. • The non-toxic effect of core shell nanoparticles was observed on normal but could eliminate the cancerous. [ABSTRACT FROM AUTHOR]

The unique properties of gold nanoparticles (Au-NPs) produce in plant extract make them attractive for use in medical and industrial applications, it is necessary to develop environmentally friendly methods for their synthesis. This can be accomplished by replacing the traditional chemical compounds for the reduction of the gold ions to Au-NPs during synthesis with natural plant extracts or with plasmas atmospheric pressure. Here, the biosynthesis of Au-NPs using the Juglans regia ( J. regia ) green husk extract was investigated as the reducing and stabilizing agent. The formation of Au-NPs was initially monitored by visual observation and then characterized with the help of various characterization techniques. UV–vis spectroscopy results showed that Au-NPs synthesized using moderate temperature have a blue shifting, good distribution and smaller size compare with Au-NPs fabricated in room temperature. X-ray diffraction (XRD) results revealed the distinctive formation of the crystalline structure of Au-NPs with a spherical shape. According to transmission electron microscopy (TEM), the mean diameter and standard deviation of Au-NPs at room and moderate temperatures were 19.19 ± 4.7 and 14.32 ± 3.24 nm, respectively. The result of Field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) are in good agreement with each other and confirm that by using the moderate temperature compare to the room temperature the yield of reaction increased. Based on the zeta potential result, Au-NPs has sufficient value for the stability of the solution. According to FTIR spectrum, the J. regia would be coated on the gold ions surface in a successful manner. The non-toxic effect of Au-NPs concentration below 250 μg/ml was observed in the studies of in vitro cytotoxicity on normal and cancerous cell lines, respectively. The dose-dependent toxicity made it a suitable candidate for various medical applications. [ABSTRACT FROM AUTHOR]

Nanoemulsions (NEs) as multi-compartmentalized systems are extensively considered as versatile drug delivery systems, due to their multifunctional and tuneable physicochemical properties. Here, water-in-oil-in-water (WOW) NEs were formulated using Juglans regia -based Fe 3 O 4 /Au-core-shell nanoparticles to encapsulate 5-Fluorouracil (5-FU) for potential colorectal cancer treatment. Response surface methodology, FTIR, TGA, TEM, DLS, VSM, UV-vis spectroscopy, and viscosity measurements were used to characterize the fabricated samples. The analysis confirmed the successful synthesis of Au, Fe 3 O 4 , and Fe 3 O 4 /Au core-shell nanoparticles with the Juglans regia (J. regia) extract as a green stabilizer and also reducing agent. The NE displayed a spherical-shape and TEM size of~30 nm. It also exhibited good colloidal stability and multifunctional features related to its components. TGA data indicated that 5-FU increased thermal stability after its loading into the nanoemulsion as a drug carrier. 5-FU release from the NE carrier presented a time-delayed behavior and higher release dosage in media at pH 4 compared to pH 7 within 48 h. When tested against colorectal-derived cell lines, 0.78 µg/mL of 5-FU-loaded Fe 3 O 4 /Au core-shell NEs showed potent anticancer activity against HCT116 cancerous cells, while exhibiting low toxicity towards CCD112 normal cells. In conclusion, the synthesized 5-FU-loaded NEs can be potently used as an anticancer drug carrier model, owing to its nano-scale size and other functionalities, which should be further studied. [ABSTRACT FROM AUTHOR]

In this research, gold nanoparticles (Au-NPs) are biosynthesized from tetrachloroaurate (AuCl4−) aqueous solution through a simple and ecofriendly route using water extract of black Camellia sinensis leaf (C. sinensis L.) which acted as a reductant and stabilizer simultaneously. The prepared gold nanoparticles are characterized using UV-visible spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Also, determination of the accurate predictor model for chemical reactions is particularly important because of high cost of the chemical materials and measurement devices. While the artificial neural networks (ANNs) are one of the appropriate tools to forecast any phenomena, due to the low number of data set related to chemical experimental was caused to provide appropriate model is a time-consuming iterative process. With the aim to improve the accuracy of the ANN model and overcome the local convergence of this problem, a global search technique, biogeography-based optimization (BBO) method which integrated by chaotic map is employed. The improved model showed minimum mean squared error (MSE) of 0.0134 and maximum coefficient of determination (R2) equal to 0.9822 compared with several other famous ANN training algorithm, utilizing output experimental data obtained from biosynthesis proceeding. [ABSTRACT FROM AUTHOR]

Abstract: The current study investigated the anticancer properties of gold nanoparticles (SG-stabilized AuNPs) synthesized using water extracts of the brown seaweed Sargassum glaucescens (SG). SG-stabilized AuNPs were characterized by ultraviolet-visible spectroscopy, transmission and scanning electron microscopy, and energy dispersive X-ray fluorescence spectrometry. The SG-stabilized AuNPs were stable and small at 3.65 ± 1.69 nm in size. The in vitro anticancer effect of SG-stabilized AuNPs was determined on cervical (HeLa), liver (HepG2), breast (MDA-MB-231) and leukemia (CEM-ss) cell lines using fluorescence microscopy, flow cytometry, caspase activity determination, and MTT assays. After 72 h treatment, SG-stabilized AuNPs was shown to be significant (p < 0.05) cytotoxic to the cancer cells in a dose- and time-dependent manner. The IC50 values of SG-stabilized AuNPs on the HeLa, HepG2, CEM-ss, MDA-MB-231 cell lines were 4.75 ± 1.23, 7.14 ± 1.45, 10.32 ± 1.5, and 11.82 ± 0.9 ±g/mL, respectively. On the other hand, SG-stabilized AuNPs showed no cytotoxic effect towards the normal human mammary epithelial cells (MCF-10A). SG-stabilized AuNPs significantly (p < 0.05) arrest HeLa cell cycle at G2/M phase and significantly (p < 0.05) activated caspases-3 and -9 activities. The anticancer effect of SG-stabilized AuNPs is via the intrinsic apoptotic pathway. The study showed that SG-stabilized AuNPs is a good candidate to be developed into a chemotherapeutic compound for the treatment of cancers especially cervical cancer. [ABSTRACT FROM AUTHOR]

Green biological synthesis of metallic nanoparticles is an important method in improved techniques of eco-friendly nanoparticle production. In the present study, gold nanoparticles (Au-NPs) were synthesized using of the brown marine algae Sargassum muticum (S. muticum) aqueous extract as both a reductant and a capping agent. The treatment of aqueous solution of gold precursors with S. muticum algae extract resulted in rapid formation of stable nanoparticles for gold. The growth of nanoparticles is monitored by UV-Vis spectrophotometer and complemented with characterization using transmission electron microscopy (TEM), X-ray diffraction, and zeta potential. The formation of Au-NPs was confirmed through the presence of an absorption peak at 550 nm using a UV-Vis spectrophotometer. A TEM image showed that the particles are spherical in shape with a mean size of 5.42 ± 1.18 nm. The capping of anionic bio-compounds on the surface of nanoparticles was confirmed by zeta potential measurement (−35.8 mV) and is responsible for the electrostatic stability. The bio-synthesized Au-NPs are expected to have notable applications in pharmaceutical and biomedical applications. [ABSTRACT FROM AUTHOR]