Design and synthesis of chitosan/agar/Ag NPs: A potent and green bio-nanocomposite for the treatment of glucocorticoid induced osteoporosis in rats

In this work we have demonstrated the green synthesis of stable and mono-dispersed Ag NPs using chitosan/Agar hydrogel having reducing/stabilizing ability avoiding any toxic reagents. Agarose was used as a green reductant for the synthesis of Ag NPs which gets stabilized by chitosan. The in situ prepared Ag NPs@CS/Agar nano bio-composite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. The Ag NPs encapsulated by CS/Agar bio-composite have a spherical shape with a mean diameter from 10 to 15 nm. Towards its bioapplication, the Ag NPs@CS/Agar nano bio-composite was administered by 5 µg/kg/day for 30 days in comparison to methyl prednisolone sodium succinate by 10 mg/kg, sc, thrice a week for 4 weeks over Wistar rats having glucocortcoid induced osteoporosis. This showed a significant increase in the serum levels of bone mineral content markers and a decrease in serum and urinary levels of bone resorption markers. An inclination in strength of femur and tibia was seen particularly with 5 µg/kg of Ag NPs@CS/Agar nano bio-composite. Maintenance of calcium homeostasis, formation of collagen and scavenging of free radicals can be the plausible mode of action of this bio-nanocomposite thereby combating osteoporosis induced by glucocorticoids.     

Immobilized Au nanoparticles on chitosan-biguanidine modified Fe3O4 nanoparticles and investigation of its anti-human lung cancer activity

In current nanoscience bioengineered magnetic nanoparticles (NPs) have come into prominence with considerable impact. These advanced functional materials find outstanding applications in chemical science in catalysis, environmental issues, sensing etc, as well as in biology as drug delivery agent, chemical therapeutics and others. We have been prompted to architect and synthesize a novel Au NP adorned over chitosan-biguanidine polyplex modified core–shell type magnetic nanocomposite (Fe₃O₄/CS-biguanidine/Au NPs). The bioshells facilitate to protect the core ferrite NPs as well as provides stability to the synthesized Au NPs by capping. The material was characterized using different analytical techniques like Fourier Transformed Infra-Red spectroscopy (FT-IR), Inductively Coupled Plasma-Optical Emission Microscopy (ICP-OES), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM) and X-ray Diffraction (XRD) studies. We explored the biological application of the nanocomposite in determining cytotoxicity of three adenocarcinoma cell lines (PC-14, LC-2/ad, HLC-1) through the MTT assay. The material showed very good activity by exhibiting very low % cell viability over the cell lines dose-dependently. The IC50 of Fe₃O₄/CS-biguanidine/Au NPs were observed 503, 398 and 475 µg/mL respectively against the three cell lines. The best output was observed at a concentration of 1000 µg/mL of catalyst in terms of cytotoxicity and inhibition of lung cancer growth. The anti-cancer potential was found in close relation to their antioxidant potential.     

A novel enzyme-mimic nanosensor based on quantum dot-Au nanoparticle@silica mesoporous microsphere for the detection of glucose

QD-Au NP@silica mesoporous microspheres have been fabricated as a novel enzyme-mimic nanosensor. CdTe quantum dots (QDs) were loaded into the core, and Au nanoparticles (NPs) were encapsulated in the outer mesoporous shell. QDs and Au NPs were separated in the different space of the nanosensor, which prevent the potential energy or electron transfer process between QDs and Au NPs. As biomimetic catalyst, Au NPs in the mesoporous silica shell can catalytically oxidize glucose as glucose oxidase (GOx)-mimicking. The resultant hydrogen peroxide can quench the photoluminescence (PL) signal of QDs in the microsphere core. Therefore the nanosensor based on the decrease of the PL intensity of QDs was established for the glucose detection. The linear range for glucose was in the range of 5–200 μM with a detection limit (3σ) of 1.32 μM.     

Synergistic contributions of multiwall carbon nanotubes and gold nanoparticles in a chitosan–ionic liquid matrix towards improved performance for a glucose sensor

We report an ingenious approach for the fabrication of a promising glucose sensor, GOx/Au/CS–IL–MWNT(SH), that exploits the synergistic beneficial characteristics of multiwalled-carbon nanotubes (MWNTs), gold nanoparticles (AuNPs), chitosan (CS) and room temperature ionic liquid (RTIL). Direct electron transfer between glucose oxidase (GOx) and electrode was achieved. Scanning electron microscopy and atomic force microscopy images of GOx/Au/CS–IL–MWNT(SH) reveal that MWNTs and AuNPs are dispersed in CS–IL matrix. Cyclic voltammetry, impedance spectroscopy and chronoamperometry were used to evaluate the performance of biosensor. The GOx/Au/CS–IL–MWNT(SH) biosensor exhibits a linear current response to glucose concentration (1–10 mM) at a low potential of 0.10 V and precludes interferences from uric acid and ascorbic acid. The GOx/Au/CS–IL–MWNT(SH) biosensor has superior performances over GOx/CS–IL–MWNT(SH).     

Synthesis of Au/C and Au/Pani for anode electrodes in glucose microfluidic fuel cell

Gold nanoparticles have been prepared by two methods: chemical (ex-situ, Au/C) by two phase protocol, and electrochemical (in-situ, Au/Pani) by electroreduction of gold ions on a polyaniline film and compared as anode catalysts in a glucose microfluidic fuel cell. In this paper the structural characteristics and electrocatalytic properties were investigated by X-ray diffraction and electrochemical measurements. The catalytic behavior of both anodes was tested in a microfluidic fuel cell with a reference electrode incorporated, by means of linear sweep voltammetry (LSV), showing a cathodic shift in the glucose oxidation peak for Au/Pani. Results show a higher power density (0.5 mW cm^? 2) for Au/C anode compared with an already reported value, where a glucose microfluidic fuel cell was used in similar conditions.     

Spectrophotometric and physicochemical investigations of Congo,alizarin red dyes and BSA interactions with Au,Ag and Au/Ag mix nanoparticles,and their antimicrobial activities

Individual and mix metal nanoparticles of Ag and Au have been prepared by the reducing method where citrate was used as reducing/stabilizing agent. The prepared NPs were characterized with UV/Visible and transmission electron microscopic (TEM) tools. The characteristic peak in UV/Visible at 525, 444 and 531 nm for Au, Ag and Ag/Au mix NPs respectively, gave primary confirmation of prepared NPs. TEM analysis showed the size of nanoparticles as 44.04, 19.78 and 30.93 nm for Ag, Au and Ag/Au mix NPs respectively. Congo and alizarin red dye interactions studies have been performed with prepared NPs to see the removal of the pollutants from water. Congo dye has shown weaker interaction as compared to alizarin due to structural symmetry. Amongst all, the AgNPs have shown maximum 67% and 75% interactions with Congo red and alizarin respectively due to high negative charges on the surface. The Au, Ag and Au/Ag mix NPs have shown stronger interaction with bovine serum albumin (BSA) protein up to 51, 59, 55% respectively, estimated through UV/Vis and physicochemical analysis. The biological evaluations of the prepared NPs have shown their antibacterial activity against Gram + ve and –ve species showing up to 9 cm zone of inhibition. The BSA interaction and antibacterial activity of NPs reveal the importance of NPs in medicinal field.     

In vitro curcumin delivery and antibacterial activity of RuS2 and RuO2 nanoparticles loaded chitosan biopolymer

In this work, RuS₂ and RuO₂ nanoparticles loaded chitosan (Chitosan was extracted from Lobsters shells of Persian Gulf, IR. Iran) was prepared and characterized via FE‐SEM, EDS and FT‐IR analysis. FESEM showed the formation of spherical nanoparticles in size ranging of 20 to 100 mm. Subsequently, the role of these new materials as curcumin drug carrier and in vitro release of curcumin in simulated body fluid (SBF) solution (pH 7.4) were studied. RuS₂‐NPs‐CS than to RuO₂‐NPs‐CS showed higher drug loading efficiency (>91%) and rapid (<90 min) curcumin drug release in SBF solution. Also, antibacterial activity of RuS₂‐NPs‐CS and RuO₂‐NPs‐CS in presens and absence of Rosemary extracts against the gram negative bacteria Pseudomonas aeruginosa (PAO 1) was evaluated by detection of minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC). MIC of RuS₂‐NPs‐CS, RuO₂‐NPs‐CS and Rosemary extracts on Pseudomonas aeruginosa strains were found to be 50 mg/ml, 50 mg/ml and 1250 mg/ml, respectively. The synergistic effect of these materials for inhibition of PAO 1 growth showed that mixture of RuS₂‐NPs‐CS and Rosemary extracts has a better efficiency than to other mixture materials.     

On demand release of ionic silver from gold-silver alloy nanoparticles: fundamental antibacterial mechanisms study

Synthesis and biomedical research of bimetallic gold-silver nanoparticles (Au–Ag NPs) have gained much attention due to their unique properties. Antibacterial mechanism of gold-silver nanoparticles is a current topic of interest in nanomedicine engineering. We used three routes in the synthesis of Au–Ag NPs alloy: i) Co-reduction of [HOOC-4-C₆H₄NN]AuCl₄/AgNO₃, ii) Seeding of AuNPs-COOH/AgNO₃ and iii) immobilization of AgNPs over the parent AuNPs-COOH. Two mild reducing agents, NaBH₄ and 9-BBN (9-borabicyclo(3.3.1)nonane), were used. Colloidal alloy nanoparticles structure was confirmed using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The particles reduced using NaBH₄ were larger (~20 nm) than those synthesized using 9-BBN (<10 nm). The synthesized nanoparticles showed high stability under notoriously leaching conditions of chloride-containing electrolytes. Moreover, we studied the Au–Ag NPs antibacterial activity against the growth of Gram-negative Escherichia coli ATCC strain 25922 and Gram-positive Staphylococcus aureus ATCC strain 29213. The antibacterial mechanisms were evaluated by studying the time-dependent generation of reactive oxygen species (ROS). A major destruction of the bacterial cell wall and leakage of cell components were observed by scanning electron microscopy (SEM), which is clearly visible towards E. coli more than S. aureus bacterial strain. The destruction of the bacterial cell wall was further confirmed by detecting the DNA leakage using gel electrophoresis. The synergistic effect of gold enhanced the antibacterial properties, however, with low cytotoxicity to human dermal fibroblast cells. This study deals with the important aspects of time-dependent mechanisms of the antibacterial action of Au–Ag NPs since the leaching out of Ag ion is slow compared to AgNPs. The Au–Ag NPs alloy efficiently tackles microbial activity that can be controlled to minimize cytotoxicity and thus opens their future applications as antibacterial agents.     

Design and synthesis of nano Cu/chitosan-starch bio-composite for the treatment of human thyroid carcinoma

In this study we report the green synthesis of nontoxic and stable Cu nanoparticles (NP) using chitosan/starch hydrogel with reducing/capping ability without using any harsh reducing agents. Starch was used as a reducing agent for the synthesis of Cu NPs that was further stabilized by chitosan polymers. The in situ prepared Cu NPs/CS-Starch bio-composite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX), X-ray Diffraction (XRD), UV–Vis, TGA and Inductively Coupled Plasma-Optical Emission Spectroscopic (ICP-OES) study. It has been established that Cu NPs/CS-Starch bio-composite have a spherical shape with a mean diameter from 5 to 7 nm. Cell viability of Cu NPs/CS-Starch bio-composite was very low against common human thyroid carcinoma cell lines i.e. TPC1, BCPAP and FTC133 without any cytotoxicity on normal cell line. The best anti-human thyroid carcinoma effects of Cu NPs/CS-Starch bio-composite was observed against the TPC1 cell line. For investigating the antioxidant properties of Cu NPs/CS-Starch bio-composite, the DPPH assay was used in the presence of butylated hydroxytoluene as the positive control. Cu NPs/CS-Starch bio-composite inhibited half of the DPPH molecules in the concentration of 207 µg/mL. The antioxidant activity of Cu NPs/CS-Starch bio-composite is significantly related to its anti-human thyroid carcinoma potentials. Based on to the above findings, the Cu NPs/CS-Starch bio-composite could be administrated for the treatment of several types of human thyroid carcinoma in humans.     

Green synthesis of plant-stabilized Au nanoparticles for the treatment of gastric carcinoma

In this study, gold nanoparticles (AuNPs) were green synthesized using plant extract. The obtained nanoparticles (Au NPs) were characterized by advanced physical and chemical techniques like TEM, FTIR, UV–vis, SEM, XRD and EDX. SEM image displayed the quasi-spherical shaped nanoparticles of mean diameter 20–50 nm. All the particles were of uniform shape and texture. From the XRD pattern, four distinct diffraction peaks at 38.2°, 44.2°, 64.7° and 77.4° are indexed as (1 1 1), (2 0 0), (2 2 0) and (3 1 1) planes of fcc metallic gold. The in vitro cytotoxic and anti-gastric carcinoma effects of biologically synthesized Au NPs against cancer cell lines were assessed. The IC₅₀ of the Au NPs were 192, 149, 76 and 85 µg/mL against NCI-N87, MKN45, GC1401 and GC1436 gastric cancer cell lines. The anti-gastric carcinoma properties of the Au NPs could significantly remove the cancer cell lines in a time and concentration-dependent manner. So, the findings of the recent research show that biologically synthesized Au NPs might be used to cure cancer.     

New potential anti-SARS-CoV-2 and anti-cancer therapies of chitosan derivatives and its nanoparticles: Preparation and characterization

Chitosan (CS) is a biopolymer and has reactive amine/hydroxyl groups facilitated its modifications. The purpose of this study is improvement of (CS) physicochemical properties and its capabilities as antiviral and antitumor through modification with 1-(2-oxoindolin-3-ylidene)thiosemicarbazide (3A) or 1-(5-fluoro-2-oxoindolin-3-ylidene)thiosemicarbazide (3B) via crosslinking of poly(ethylene glycol)diglycidylether (PEGDGE) using microwave-assisted as green technique gives (CS-I) and (CS-II) derivatives. However, (CS) derivatives nanoparticles (CS-I NPs) and (CS-II NPs) are synthesized via ionic gelation technique using sodium tripolyphosphate (TPP). Structures of new (CS) derivatives are characterized using different tools. The anticancer, antiviral efficiencies and molecular docking of (CS) and its derivatives are assayed. (CS) derivatives and its nanoparticles show enhancement in cell inhibition toward (HepG-2 and MCF-7) cancer cells in comparison with (CS). (CS-II NPs) reveals the lowest IC₅₀ values are 92.70 ± 2.64 μg/mL and 12.64 µ g/mL against (HepG-2) cell and SARS-CoV-2 (COVID-19) respectively and the best binding affinity toward corona virus protease receptor (PDB ID 6LU7) ?5.71 kcal / mol. Furthermore, (CS-I NPs) shows the lowest cell viability% 14.31 ± 1.48 % and the best binding affinity ?9.98 kcal/moL against (MCF-7) cell and receptor (PDB ID 1Z11) respectively. Results of this study demonstrated that (CS) derivatives and its nanoparticles could be potentially employed for biomedical applications.     

Using reversed-phase liquid chromatography to monitor the sizes of Au/Pt core/shell nanoparticles

This paper describes the use of reversed-phase liquid chromatography (RPLC) to rapidly characterize Au/Pt core/shell nanoparticles (NPs) produced through seed-assisted synthesis. We monitored the sizes of Au/Pt core/shell NPs by using a porous silica-based RPLC column (pore size: ca. 100 nm) and 30 mM sodium dodecyl sulfate in deionized water as the mobile phase; the plot of the retention time with respect to the logarithm of the size of the Au NPs was linear (R² = 0.997) for diameters falling in the range from 5.3 to 40.1 nm; from five consecutive runs, the relative standard deviations of these retention times were less than 0.4%. We used the optimal separation conditions of the RPLC system to study the effects that the rate of addition of the reducing agent and the volumes of the seed, shell precursor metal ion, and reducing agent solutions had on the sizes of the Au/Pt core/shell NPs. A good correlation existed between the sizes of the Au/Pt core/shell NPs determined through RPLC and those determined using transmission electron microscopy. RPLC appears to be a useful technique for monitoring the sizes of NPs and nanomaterials in general.     

Pulmonary protective effects of ultrasonic green synthesis of gold nanoparticles mediated by pectin on Methotrexate-induced acute lung injury in lung BEAS-2B,WI-38, CCD-19Lu,IMR-90, MRC-5, and HEL 299 cell lines

Regarding applicative, facile, green chemical research, a bio-inspired approach is being reported for the synthesis of Au nanoparticles by pectin (PEC) as a natural reducing and stabilizing agent without using any toxic and harmful reagent under ultrasonic condition. The biosynthesized Au NPs@PEC were characterized by advanced physicochemical techniques like ultraviolet–visible (UV–Vis), Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX), and X-ray Diffraction (XRD) study. It has been established that pectin-stabilized Au nanoparticles have a spherical shape with a mean diameter from 5 to 10 nm. In the medicinal part of the present research, the lung BEAS-2B, WI-38, CCD-19Lu, IMR-90, MRC-5, and HEL 299 cell viability was determined by trypan blue assay. The caspase activity colorimetric assay kit and Rhodamine123 fluorescence dye were used to determine the caspase-3 activity and mitochondrial membrane potential, respectively. Apoptosis and DNA fragmentation were determined by the TUNEL test. Also, the inflammatory cytokines concentrations were evaluated by the Rat inflammatory cytokine assay kit. Au NPs@PEC-treated cell cutlers decreased significantly (p ≤ 0.01) the caspase-3 activity, inflammatory cytokines concentrations, and DNA fragmentation, and enhanced the mitochondrial membrane potential and cell viability in the high concentration of Methotrexate-treated lung BEAS-2B, WI-38, CCD-19Lu, IMR-90, MRC-5, and HEL 299 cells. In the antioxidant test, the IC50 of Au NPs@PEC nanocomposite and BHT against DPPH free radicals were 203 and 181 µg/mL, respectively. Finally, Au NPs@PEC may be used as a pulmonary protective supplement to treat acute lung injury.     

Physico-chemical characterization and anti-laryngeal cancer effects of the gold nanoparticles

Most recently, gold nanoparticles due to anticancer properties have been considered in medical science. So the aim of the study was green synthesis of gold nanoparticles using Ocimum basilicum extract and its anticancer activity. The prepared Au nanoparticles were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX), X-ray Diffraction (XRD) and UV–vis spectroscopy study. It has been established that Au nanoparticles have a spherical shape with a mean diameter from 19 to 44 nm. In the cellular and molecular part of the recent study, the treated cells with Au nanoparticles were assessed by MTT assay for 48 h about the cytotoxicity and anti-human laryngeal cancer properties on normal (HUVEC) and cancer (HEp-2, TU212, KB, UM-SCC-5, UM-SCC-11A and UM-SCC-11B) cell lines. In the antioxidant test, the IC50 of Au nanoparticles and BHT against DPPH free radicals were 228 and 208 µg/mL, respectively. The IC50 of Au nanoparticles were 174, 231, 179, 143, 230, and 216 µg/mL against HEp-2, TU212, KB, UM-SCC-5, UM-SCC-11A and UM-SCC-11B cell lines, respectively. The viability of malignant cell lines reduced dose-dependently in the presence of Au nanoparticles. It appears that the anti-cancer effect of Au nanoparticles e to their antioxidant effects.     

Investigation of anti-human ovarian cancer effects of decorated Au nanoparticles on Thymbra spicata extract modified Fe3O4 nanoparticles

This work describes an eco-friendly approach for in situ immobilization of Au nanoparticles on the surface of Fe₃O₄ nanoparticles, with the help of Thymbra spicata extract and ultrasound irradiations, without using any toxic reducing and capping agents. The combination of Fe₃O₄ NPs and Au NPs in one hybrid nanostructure (Fe₃O₄@Thymbra spicata/Au NPs) represents a promising strategy for targeted biomedical applications. The structure, morphology, and physicochemical properties were characterized by various analytical techniques such as fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and vibrating sample magnetometer (VSM). MTT assay was used on common ovarian cancer cell lines i.e., SW-626, PA-1, and SK-OV-3 to survey the cytotoxicity and anti-ovarian cancer effects of Fe₃O₄@Thymbra spicata/Au NPs. The best results of cytotoxicity and anti-ovarian cancer properties were seen in the concentration of 1000 µg/mL. Fe₃O₄@ Thymbra spicata/Au NPs had very low cell viability and high anti-ovarian cancer activities dose-dependently against PA-1, SW-626, and SK-OV-3 cell lines without any cytotoxicity on the normal cell line (HUVEC). For investigating the antioxidant properties of Fe₃O₄@ Thymbra spicata/Au NPs, the DPPH test was used in the presence of butylated hydroxytoluene as the positive control. Fe₃O₄@Thymbra spicata/Au NPs inhibited half of the DPPH molecules in the concentration of 107 µg/mL. Maybe significant anti-human ovarian cancer potentials of Fe₃O₄@Thymbra spicata/Au NPs against common human ovarian cancer cell lines are linked to their antioxidant activities. After confirming the above results in the clinical trial researches, this formulation can be administrated for the treatment of several types of human ovarian cancers in humans.     

A Label‐Free Amperometric Immunosensor Based on Redox‐Active Ferrocene‐Branched Chitosan/Multiwalled Carbon Nanotubes Conductive Composite and Gold Nanoparticles

A novel immunosensor has been developed by self‐assembling Au NPs onto a ferrocene‐branched chitosan/multiwalled carbon nanotubes (CS‐Fc/MWCNTs) modified electrode for the sensitive determination of hepatitis B surface antigen (HBsAg). The formation of CS‐Fc effectively avoids the leakage of Fc and retains its electrochemical activity. Incorporation of MWCNTs and Au NPs into CS‐Fc further increases the electrochemical active Fc in the CS films and provides interactive sites for the immobilization of HBsAb. The morphologies and electrochemistry of the formed biofilm were investigated by using scanning electron microscopy and electrochemical techniques. The immunosensor exhibits a specific response to HBsAg in the range of 1.0–420 ng mL^?1. Excellent analytical performance, fabrication reproducibility and operational stability of the proposed immunosensor indicated its promising application in clinical diagnostics.     

Monitoring Stability and Sizes of Au/Pd Core/Shell Nanoparticles by SEC

This paper describes how size exclusion chromatography (SEC) can be used to rapidly characterize Au/Pd core/shell nanoparticles (NPs). We monitored the sizes of Au/Pd core/shell NPs by effecting SEC separation using a mobile phase of 10 mM sodium dodecyl sulfate (SDS); the plot of retention time with respect to the standard size of the Au NPs was linear (R ² = 0.991) for diameters falling in the range from 12.1 to 59.9 nm; for five consecutive runs, the relative standard deviations of these retention times were less than 0.4%. Under the optimized separation conditions, we found that the addition of the surfactant SDS stabilized the Au/Pd core/shell NP samples. In addition, SEC analysis revealed that the sizes of the Au/Pd core/shell NPs could be controlled via modification of the rate of addition of the reducing agent and the use of adequate volumes of the seed and shell precursor metal ion solutions. When using these conditions to analyze the Au/Pd core/shell NPs produced through seed-assisted synthesis, a good correlation existed between the sizes determined through SEC and transmission electron microscopy. Our results suggest that SEC is a useful technique for monitoring the sizes of NPs and nanomaterials in general.     

Bionanocomposite of Au decorated MnO2 via in situ green synthesis route and antimicrobial activity evaluation

Green synthesis gaining a significant importance for the preparation of nanoparticles (NPs) and NPs-based biocomposites gained much attention in biological applications. In the current study, gold (Au) nanoparticles were prepared via green approach using cinnamon extract. The Au nanocomposite (NC) was prepared with MnO₂ nanofiber mesh structure. The NC was characterized by XRD, SEM, FT-IR, EDX, UV–visible and DLS techniques. The MnO₂ nanofibers diameter was in 10–25 nm range, which was arranged in a mesh form and Au NPs was combined with nanofibers randomly. The MnO₂-Au NC antimicrobial activity was measured against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus strains. The antimicrobial activity of MnO₂-Au NC was highly promising against tested microorganisms in comparison to control (ciprofloxacin, a standard drug). The antimicrobial activity of MnO₂-Au NC was found in following order; > S. aureus > E. coli > P. aeruginosa with the zones inhibition of 22, 18 and 15 (mn), respectively. The MIC (minimum inhibitory concentration) values were 316, 342 and 231 (µg/mL) for E. coli, P. aeruginosa and S. aureus, respectively. In view of promising antimicrobial activity, the MnO₂-Au NC prepared via green approach could have potential applications in medical field and future study can be engrossed on the biocompatibility evaluation of MnO₂-Au NC using bioassays.     

Localized surface plasmon resonance sensing detection of glucose in the serum samples of diabetes sufferers based on the redox reaction of chlorauric acid

In this paper, the formation of gold nanoparticles (Au NPs) as a result of the thermo-active redox reaction of chlorauric acid (HAuCl₄) and glucose in alkaline medium was identified by measuring the plasmon resonance absorption, localized surface plasmon resonance (LSPR), and transmission electron microscopy (TEM) images, for the formation of Au NPs displays characteristic plasmon resonance absorption bands and corresponding LSPR signals. It was found that the resulted LSPR signals could be easily detected with a common spectrofluorometer. With increasing glucose concentration, the LSPR intensity displays linear response with the glucose content over the range from 2.0 to 250.0 μmol l⁻¹. Thus, a novel assay of glucose was established with the limits of determination (3σ) being 0.21 μmol l⁻¹, and the detection of glucose could be made easily in the serum samples of diabetes sufferers. Mechanism investigations showed that the activation energy and molar ratio of the reaction were 34.8 kJ mol⁻¹ and 3:2, respectively.     

Regulation of the PI3K/AKT/mTOR signaling pathway with synthesized bismuth oxide nanoparticles from Ginger (Zingiber officinale) extract: Mitigating the proliferation of colorectal cancer cells

In order to overcome the limitations of conventional therapeutic systems in the treatment of cancer, nanoparticles (NPs) have been rapidly produced and developed as a separate treatment method for control of cancer. Synthesis of nanoparticles using plant-based materials (green synthesis), due to the easy and cost-effective synthesis, production of non-toxic, sustainable and environmentally friendly products, can be considered the most appropriate method for preparation of NPs. In this study, after synthesis of Bi₂O₃ NPs using Ginger (Zingiber officinale) root (rhizome) extract, the synthesized NPs were characterized and their potential application as selective anticancer agents against HCT116 colorectal cancer cells was evaluated through regulation of PI3K/AKT/mTOR signaling pathway, whereas the human kidney (HK-2) cells were used as normal cells. FTIR analysis showed a band at 673 cm^?1 attributed to Bi-O vibration with a fingerprint region at 1291 cm^?1 demonstrating the attachment of the organic molecules to the synthesized Bi₂O₃ NPs. UV–visible study showed a λ_max of around 268 nm, whereas XRD analysis showed eight clear peaks, demonetizing the crystalline phase of synthesized Bi₂O₃ NPs. TEM analysis showed that spherical-shaped Bi₂O₃ NPs have a size range of 20–50 nm with a man size of around 35 nm. Finally, DLS analysis determined that Bi₂O₃ NPs have a hydrodynamic size of about 71.19 nm (PDI of 0.179) and a zeta potential value of ?44.39 mV, revealing the good colloidal stability of NPs. Cellular assays (MTT, LDH, flow cytometry, and RT-qPCR) showed that synthesized Bi₂O₃ NPs selectively induced anticancer effects against HCT116 colorectal cancer cells through membrane leakage, generation of ROS, induction of apoptosis via dysregulation of Bax, Bcl-2 and caspase-3 at mRNA level mediated via regulation of PI3K/AKT/mTOR signaling pathway. In conclusion, it may be suggested that the presence study could provide useful information for the potential anticancer effects mediated by synthesized Bi₂O₃ NPs in vitro, although further studies, including in vivo studies and clinical trials, are needed to support our findings.