In the study, leaf extract of Carica papaya was utilized for the biogenic fabrication process of chitosan functionalized silver nanoparticles (Ag-Chito NPs). HRTEM analysis revealed that the ...fabricated Ag-Chito NPs was spherical in shape, with an average particle size of 13.31 (±0.07) nm. FTIR, UV–Vis, DLS, and other characterizations were also performed to analyze the diverse physicochemical properties of the particles. The antibacterial potency of the synthesized Ag-Chito NPs was tested against the two clinically isolated multidrug resistant uropathogenic bacterial strains, i.e. MLD 2 (Escherichia coli) and MLD 4 (Staphylococcus aureus) through MIC, MBC, time and concentration dependent killing kinetic assay, inhibition of biofilm formation assay, fluorescence and SEM imaging. Significantly, Ag-Chito NPs showed the highest sensitivity against the MLD 2 (MIC value of 12.5 μg/mL) strain, as compared to the MLD 4 (MIC value of 15 μg/mL) strain. From the hemolysis assay, it was revealed that Ag-Chito NPs exerted no significant toxicity up to 50 μg/mL against healthy human blood cells. Additionally, in silico analysis of chitosan (functionalized on the surface of AgNPs) and bacterial cell membrane protein also evidently suggested a strong interaction between Ag-Chito NPs and bacterial cells, which might be responsible for bacterial cell death.
•Biogenic fabrication of chitosan functionalized silver nanoparticles.•Promising antibacterial potency against multidrug resistant bacterial strain•Fabricated nanoparticles hold promising cytocompatibility.•Molecular docking explains the interaction of the particle with bacterial proteins.
Seven dinuclear and one dinuclear based dicyanamide bridged polymeric Ni(II) complexes of phenol based compartmental ligands (HL(1)-HL(4)) have been synthesized with the aim to investigate their ...catecholase-like activity and to evaluate the most probable mechanistic pathway involved in this process. The complexes have been characterized by routine physicochemical studies as well as by X-ray single crystal structure analyses namely Ni2(L(2))(SCN)3(H2O)(CH3OH) (), Ni2(L(4))(SCN)3(CH3OH)2 (), Ni2(L(2))(SCN)2(AcO)(H2O) (), Ni2(L(4))(SCN)(AcO)2 (), Ni2(L(2))(N3)3(H2O)2 (), Ni2(L(4))(N3)3(H2O)2 (), Ni2(L(1))(AcO)2(N(CN)2)n () and Ni2(L(3))(AcO)2(N(CN)2) (), SCN = isothiocyanate, AcO = acetate, N3 = azide, and N(CN)2 = dicyanamide anion; L(1-4) = 2,6-bis(R2-iminomethyl)-4-R1-phenolato, where R1 = methyl and tert-butyl, R2 = N,N-dimethyl ethylene for L(1-2) and R1 = methyl and tert-butyl, R2 = 2-(N-ethyl) pyridine for L(3-4). A UV-vis spectrophotometric study using 3,5-di-tert butylcatechol (3,5-DTBC) reveals that all the complexes are highly active in catalyzing the aerobic oxidation of (3,5-DTBC) to 3,5-di-tert-butylbenzoquinone (3,5-DTBQ) in methanol medium with the formation of hydrogen peroxide. An EPR study confirms the generation of radicals during the catalysis. Cyclic voltammetric studies of the complexes in the presence and absence of 3,5-DTBC have been performed. Reduction of Ni(II) to Ni(I) and that of the imine bond of the ligand system have been detected at ∼-1.0 V and ∼-1.5 V, respectively. Coulometric separation of the species at -1.5 V followed by the EPR study at 77 K confirms the species as an organic radical and thus most probably reduced imine species. Spectroelectrochemical analysis at -1.5 V clearly indicates the oxidation of 3,5-DTBC and thus suggests that the radical pathway is supposed to be responsible for the catecholase-like activity exhibited by the nickel complexes. The ligand centred radical generation has further been verified by density functional theory calculation.
Abstract Doxorubicin (DOX) is a well-known drug used to treat a wide range of solid tumor and hematological malignancies, but the use of this drug is now restricted owing to its severe side effects, ...including normal cellular toxicity. This study was conducted to evaluate the potency of self-assembled betulinic acid (SA-BA) against DOX induced chemotherapeutic toxicity in human peripheral blood lymphocytes (PBLs). The isolated betulinic acid from the bark of Ziziphus jujuba tree was purified by column chromatography and characterized by FT–IR, XRD,1 H NMR and self-assembly property was investigated by SEM imaging. DOX treatment produced significant reduction of viability of PBLs mainly by lowering cellular anti-oxidant pool and elevating the reactive oxygen species level. Pre-treatment with SA-BA followed by DOX exposure for 24 h protected the PBLs from DOX induced oxidative stress. Potent anti-apoptotic role of SA-BA was also confirmed by FACS analysis and western blot assay. Severe inflammation is one of the major concerns in DOX treatment. We found that pre-treatment with SA-BA on PBLs significantly protected the PBLs from DOX induced inflammation. Thus, our finding confirms that SA-BA can be used to ameliorate the cytotoxic effects of DOX, which can be a helpful strategy during DOX mediated chemotherapy in cancer patients.
The objective of this study was to develop folate receptor mediated delivery of self assembled betulinic acid nano fibers (SA-BA) to human leukemic cells and to investigate their specific induction ...of apoptosis. The physicochemical properties of PEG conjugated SA-BA followed by conjugated with folic acid (FA–PEG–SA-BA) were examined using Fourier transform infrared spectroscopy, thermogravimetry analysis, X-ray diffraction analysis, thin layer chromatography and scanning electron microscopy. The stability of folic acid with PEG–SA-BA conjugate was higher at acidic pH, which helps to maintain the conjugate structure for internalization of folate receptor over expressing cells. FA–PEG–SA-BA showed good compatibility with normal cells. The internalization of FA–PEG–SA-BA was significantly observed in folate receptor over expressing K562 cells while showing comparatively lower impact on folate receptor lower expressing KG-1A cells. This intracellular localization of conjugate facilitated the generation of excess reactive oxygen species (ROS), followed by elevation of tumor necrosis factor alpha (TNF-α) secretion. The effective contribution of ROS and TNF-α in FA–PEG–SA-BA mediated leukemic cell death was confirmed by pretreatment of cells with the ROS scavenger ( N -acetyl- l -cysteine) and pentoxifylline, a potent TNF-α blocker. The mode of leukemic cell death was confirmed by flow-cytometric analysis. We also tested the possible involvement of caspase activation in TNF-α mediated leukemic cell death by immunoflouroscence staining of apoptotic marker proteins (caspase 8 and caspase 3).
The objective of this study was to develop chitosan-based delivery of cobalt oxide nanoparticles to human leukemic cells and investigate their specific induction of apoptosis. The physicochemical ...properties of the chitosan-coated cobalt oxide nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, X-ray diffraction, and Fourier transform infrared spectroscopy. The solubility of chitosan-coated cobalt oxide nanoparticles was higher at acidic pH, which helps to release more cobalt ions into the medium. Chitosan-coated cobalt oxide nanoparticles showed good compatibility with normal cells. However, our results showed that exposure of leukemic cells (Jurkat cells) to chitosan-coated cobalt oxide nanoparticles caused an increase in reactive oxygen species generation that was abolished by pretreatment of cells with the reactive oxygen species scavenger
N
-acetyl-
l
-cysteine. The apoptosis of Jurkat cells was confirmed by flow-cytometric analysis. Induction of TNF-α secretion was observed from stimulation of Jurkat cells with chitosan-coated cobalt oxide nanoparticles. We also tested the role of TNF-α in the induction of Jurkat cell death in the presence of TNF-α and caspase inhibitors. Treatment of leukemic cells with a blocker had a greater effect on cancer cell viability. From our findings, oxidative stress and caspase activation are involved in cancer cell death induced by chitosan-coated cobalt oxide nanoparticles.
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Growing interest in sustainable agriculture has prompted this study aiming to evaluate nutritional content of rice grain produced from an organic production system. Here, we grew nine quality rice ...cultivars under organic methods in the wet and dry seasons, and the nutritional values, grain quality, and physiological parameters were compared with respective cultivars grown under the standard cultivation method (SCM). Obtained results revealed that the yield and plant height were lower, but tillering capacity was higher, in the organic field compared with the standard one. The organic crop showed significantly lower contents of protein and phytate compared with reference values under the SCM. Antioxidative capacity and its responsible phytochemicals such as phenolics, flavonoids, and γ‐oryzanol were also significantly higher under organic cultivation than under the SCM. Among physicochemical characteristics, apparent amylose content, gel consistency, and area and perimeter of grain were also higher in the organic crops, but hulling quality, milling quality, head rice recovery, and all other cooking qualities were at par. Higher crude oil and lower total protein content of rice bran were observed in the organic crop, but ash, fiber, and moisture contents did not vary significantly in these two cultivation systems.
The purpose of this study is to evaluate the prospect of using surface modified cobalt oxide(CoO) nanoparticles as carriers of cancerantigens to human macrophages.
N
-Phosnomethyliminodiacetic acid ...(PMIDA) was used for surface modification to overcome the toxic effect of CoO nanoparticles. Here, the phosphonate group of the PMIDA acts as a surface-anchoring agent and the remaining –COOH groups bind nonspecifically with tumor associated antigens. This modification allows the conjugation of human oral carcinoma (KB) cell lysate (CL) as an antigen with PMIDA coated CoO nanoparticles (CL–PMIDA–CoO). Particle characterization was performed by dynamic light scattering, atomic force microscopy, and scanning electron microscopy studies. Fourier transform IR spectroscopy was used to investigate conjugation of the protein with nanoparticles. Protein encapsulation was confirmed by protein gel electrophoresis. Active uptake of antigen-conjugated nanoparticles by macrophages was confirmed by fluorescence microscopy. The antitumor activity of the nanocomplex pulsed macrophages was investigated on a human oral carcinoma cell line (KB) in vitro. The modified nanocomplexes upregulate IFN-γ and TNF-α and induce an anticancer immune response by activating macrophages. The use of TNF-α inhibitor confirmed the ability of the CL–PMIDA–CoO nanocomplex to stimulate TNF-α mediated immunostimulation. CL–PMIDA–CoO nanoparticles efficiently increased the CD4
+
population. Thus, our findings provide insight into the use of PMIDA coated CoO nanoparticles as antigen delivery vehicles.
Graphical abstract
The aim of our study was to prepare multifunctional, biocompatible nanoparticles for site-specific drug delivery. Hydrophilic nanoparticles with surface-adorned amine, carboxyl, or aldehyde groups, ...to be later used for bio-conjugation, were designed using phosphonomethyl iminodiacetic acid (PMIDA) as the coupling agent. These PMIDA-coated cobalt oxide nanoparticles (PMIDA-CoO) were further functionalized with folic acid (FA), using simple technique. The particles show excellent aqueous dispersion stability in physiological pH without any deterioration in hydrodynamic size. The cytotoxicity and internalization efficiency of these nanocarriers have been evaluated on folate receptor over expressed KB and folate receptor lower expressed KG1a cells. Anticancer drugs such as doxorubicin and methotrexate were successfully attached to the folic acid-decoded PMIDA-CoO nanoparticles by simple reactions. Anticancer drug-loaded nanoparticles (FA-PMIDA-CoO) exhibit elevated cytotoxicity and induce apoptosis in cancer cells, which were confirmed by flow cytometry. Fluorescence microscopy study shows the higher amount of internalization of the noncomplex by KB cells, which clearly demonstrated that cells overexpressing the human folate receptor internalized a higher level of these nanoparticles–folate conjugates than folate receptor-negative control cells.
Two varieties of Co 3 O 4 nano particles (Co 3 O 4 -I and Co 3 O 4 -II) have been synthesized from two different precursors using a pyrolytic technique. Co 3 O 4 -I was prepared by using a ...coordination polymer Co(dca) 2 (2-benzoylpyridine) n (dca = dicyanamide) as sole precursor, whereas Co 3 O 4 -II was obtained from a dinuclear complex Co 2 (HL)(OAc) 2 (OAc) 2 ·4H 2 O HL = 2,6-bis( N -ethylpiperazine-iminomethyl)-4-methyl phenol. The synthesized nanoparticles were characterized by FTIR spectroscopy, magnetic measurements and X-ray diffraction studies. Both Co 3 O 4 -I and Co 3 O 4 -II are high-quality mono-dispersed, stable and defect-free nanoparticles. The surface morphology of these nanoparticles was revealed by scanning electron microscopy. Co 3 O 4 -I nanoparticles have square shape and size ranging from 10 to 25 nm, whereas Co 3 O 4 -II nanoparticles have hexagonal shape with larger particle size (100–150 nm). The size distribution of the nanoparticles was determined by dynamic light scattering. The particle size and microstructure were studied by transmission electron microscopy (TEM) images. These nanoparticles show an effective anti-microbial activity, employing Staphylococcus aureus and Escherichia coli as model microbial species, evidenced from the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values.
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