Chitosan-sialic acid nanoparticles of selenium: Statistical optimization of production, characterization, and assessment of cytotoxic effects against two human glioblastoma cell lines.

According to the favorable antitumor properties of selenium, this study aimed to design a novel form of selenium nanoparticles (Se NPs) functionalized with chitosan (Cs) and sialic acid to assess their antitumor effects on the human glioblastoma cell lines (T98 and A172). Se NPs were synthesized in the presence of chitosan and ascorbic acid (Vc) and the synthesis conditions were optimized using response surface methodology. Se NPs@Cs were obtained with a monoclinic structure with an average diameter of 23 nm under the optimum conditions (reaction time = 30 min, chitosan concentration = 1 % w/v, Vc/Se molar ratio = 5). To modify Se NP@Cs for glioblastoma treatment, sialic acid was used to cover the surface of the NPs. Sialic acid was successfully attached to the surface of Se NPs@Cs, and Se NPs@Cs-sialic acid were formed in the size range of 15-28 nm. Se NPs@Cs-sialic acid were stable for approximately 60 days at 4 ℃. The as-synthesized NPs exerted inhibitory effects on T98 greater than 3 T3 > A172 cells in a dose- and time-dependent manner. Additionally, sialic acid ameliorated the blood biocompatibility of Se NPs@Cs. Taken together, sialic acid improved both the stability and biological activity of Se NPs@Cs.

Isolation, Optimization, and Structural Characterization of Glycolipid Biosurfactant Produced by Marine Isolate Shewanella algae B12 and Evaluation of Its Antimicrobial and Anti-biofilm Activity.

Biosurfactants are microbial-derived compounds with surface and emulsifying activities. Environmental and industrial applications make glycolipid biosurfactants particularly interesting among the several categories of biosurfactants. A potential glycolipid biosurfactant resource, Shewanella algae, was isolated from marine samples at the Persian Gulf. The glycolipid biosurfactant caused a reduction in water surface tension from 72 to 43 mN/m with a 0.25 mg/mL critical micelle concentration (CMC). Two-level factorial design was then applied for optimization of biosurfactant production, where a maximal reduction of culture broth surface tension (31 mN/m) acquired in the presence of crude oil (0.5%, v/v), NaNO3 (0.2 g/L), NH4Cl (0.7 g/L), and peptone (0.5 g/L). GC-MS analysis of the culture broth showed when crude oil was used as the sole carbon source, S. algae was able to degrade most of its alkane components. Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy revealed the glycolipid structure of biosurfactant. The glycolipid biosurfactant exhibited considerable growth inhibition of clinical bacterial pathogens and disrupted the preformed biofilms of Bacillus cereus (83%), Streptococcus pneumoniae (53%), Pseudomonas aeruginosa (92%), Escherichia coli (64%), Klebsiella pneumoniae (87%), and Acinetobacter sp. (72%). In conclusion, the glycolipid biosurfactant secreted by S. algae exhibited a wide range of functional properties and was evidenced as a promising candidate for biomedical application.

Bioactive anti-oxidative polycaprolactone/gelatin electrospun nanofibers containing selenium nanoparticles/vitamin E for wound dressing applications.

In this study, polycaprolactone/gelatin (PCL/GEL) electrospun nanofibers containing biogenic selenium nanoparticles (Se NPs) and Se NPs/vitamin E (VE) with average diameters of 397.8 nm and 279.5 nm, respectively (as determined by SEM inspection) were prepared and their effect on wound healing was evaluated using in-vivo studies. The energy dispersive X-ray (EDX) mapping, TEM micrograph, and FTIR spectra of the prepared nanofibers strongly demonstrated well entrapment of Se NPs and VE into scaffolds. An amount of 57% Se NPs and 43% VE were gradually released from PCL/GEL/Se NPs/VE scaffold after 4 days immersion in PBS solution (pH 7.4). The both PCL/GEL/Se NPs and PCL/GEL/Se NPs/VE scaffolds supported 3T3 cell proliferation and attachment as confirmed by MTT assay and SEM imaging. Complete re-epithelialization, low level of edema and inflammatory cells in coordination with high level of oriented collagens demonstrated the wound healing activity of PCL/GEL/Se NPs/VE. Besides, significant antioxidant efficacy of PCL/GEL/Se NPs and PCL/GEL/Se NPs/VE scaffolds was demonstrated according to GSH and MDA assays. To sum up, the prepared PCL/GEL/Se NPs/VE scaffold in the present study represented suitable healing effect on animal model which candidate it for further studies.

Rapid and Facile Microwave-Assisted Synthesis of Palladium Nanoparticles and Evaluation of Their Antioxidant Properties and Cytotoxic Effects Against Fibroblast-Like (HSkMC) and Human Lung Carcinoma (A549) Cell Lines.

We report here a simple microwave irradiation method (850 W, 3 min) for the synthesis of palladium nanoparticles (Pd NPs) using ascorbic acid (as reducing agent) and sodium alginate (as stabilizer agent). The synthesized nanoparticles were characterized using transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), UV-Visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. Antioxidant properties and cytotoxic effects of as-synthesized Pd NPs and Pd (II) acetate were also assessed. UV-Vis study showed the formation of Pd NPs with maximum absorption at 345 nm. From TEM analysis, it was observed that the Pd NPs had spherical shape with particle size distribution of 13-33 nm. Based on DPPH radical scavenging activity and reducing power assay, the antioxidant activities of Pd NPs were significantly higher than the Pd (II) acetate (p < 0.05). At the same concentration of 640 µg/mL, the scavenging activities were 32.9 ± 3.2% (Pd (II) acetate) and 27.2 ± 2.1% (Pd NPs). For A549 cells treated 48 h with Pd NPs, Pd (II) acetate, and cisplatin, the measured concentration necessary causing 50% cell death (IC50) was 7.2 ± 1.7 µg/mL, 32.1 ± 2.1 µg/mL, and 206.2 ± 3.5 µg/mL, respectively. On HSkMC cells, the IC50 of the Pd NPs (320 µg/mL) was higher compared to Pd (II) acetate (228.7 ± 3.6 µg/mL), which confirmed lower cytotoxicity of the Pd NPs.

Antioxidant, cytotoxic and hyperalgesia-suppressing activity of a native Shilajit obtained from Bahr Aseman mountains.

Shilajit, a blackish-brown exudation obtained from steep rocks of different mountains, has been longly used as a therapeutic agent in traditional medicine. The present study was designed to evaluate the antioxidant, cytotoxic and hyperalgesia-suppressing activity of the aqueous and DMSO extracts of a native Shilajit. The antioxidant and cytotoxic effects of Shilajit extracts was determined using DPPH scavenging activity and MTT assay methods, respectively. In order to examine the hyperalgesia-suppressing activity of the Shilajit aqueous extract the STZ-induced diabetic animals were subjected to oral administration of the extract (50, 100 and 200 mg/kg daily) for six weeks followed by evaluating the behavioral examination (hot plate and tail flick tests) compared to those of diabetic control (Sham) and vehicle groups. The obtained results of antioxidant evaluation of Shilajit represented scavenging activity of 50% at concentration of 2500 µg/mL and 6000 µg/mL in the case of aqueous and DMSO extracts, respectively. Cytotoxic study of water extract of Shilajit revealed IC50 of 727.5±1.9 µg/mL and 1103±3.2 µg/mL on cell lines of MCF-7 (breast cancer) and A549 (lung cancer), respectively. Thermal pain response examination of diabetic rats treated with aqueous extract of Shilajit (100 mg/kg and 200 mg/kg) for six weeks reduced hyperalgesia compared to vehicle and Sham groups. To sum up, considering the moderate antioxidant and hyperalgesia-suppressing activity of this native Shilajit make it as a suitable candidate for further investigation after isolation and characterization of the active compounds.

Antimicrobial and anti-biofilm activities of Bi subnitrate and BiNPs produced by Delftia sp. SFG against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis.

In the present study Delftia sp. Shakibaie, Forootanfar, and Ghazanfari (SFG), was applied for preparation of biogenic Bi nanoparticles (BiNPs) and antibacterial and anti-biofilm activities of the purified BiNPs were investigated by microdilution and disc diffusion methods. Transmission electron micrographs showed that the produced nanostructures were spherical with a size range of 40-120 nm. The measured minimum inhibitory concentration of both the Bi subnitrate and BiNPs against three biofilms producing bacterial pathogens of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis were found to be above 1280 µg/ml. Addition of BiNPs (1000 µg/disc) to antibiotic discs containing tobramycin, nalidixic acid, ceftriaxone, bacitracin, cefalexin, amoxicillin, and cefixime significantly increased the antibacterial effects against methicillin-resistant S. aureus (MRSA) in comparison with Bi subnitrate (p < 0.05). Furthermore, the biogenic BiNPs decreased the biofilm formation of S. aureus, P. aeruginosa, and P. mirabilis to 55, 85, and 15%, respectively. In comparison to Bi subnitrate, BiNPs indicated significant anti-biofilm activity against P. aeruginosa (p < 0.05) while the anti-biofilm activity of BiNPs against S. aureus and P. mirabilis was similar to that of Bi subnitrate. To sum up, the attained results showed that combination of biogenic BiNPs with commonly used antibiotics relatively enhanced their antibacterial effects against MRSA.

Toxicity of microwave-assisted biosynthesized zinc nanoparticles in mice: a preliminary study.

This study was designed to describe the oral acute and subacute toxicities and underlying toxicological mechanisms of biogenic Zn NPs in mice. The Zn NPs were prepared by a green microwave-assisted synthesis method in the presence of Lavandula vera leaf extract. Determination of median lethal dose (LD50) of Zn NPs and the subacute toxicity after 14 days of exposure was performed as a measurement of substance toxicity through general toxicological, hematological, serum, and histopathological investigations. The western blotting was used to determine the cleaved-caspase-3 expression in the sampled tissues. Flame atomic absorption spectrophotometer (AAS) was applied to estimate the Zn levels in tissues. The SEM analyses revealed that the biogenic Zn NPs were spherical-shaped with the size range of 30-80 nm. The LD50 value above 5 g/kg indicated that biogenic Zn NPs could be classified as non-toxic chemicals. In subacute toxicity, no significant differences were found in the body weight as well as hematological and oxidative stress (OS) biomarkers after exposure to Zn NPs at the dose of 1 g/kg in comparison to the control. The AAS results indicated that Zn NPs were mainly distributed in the testis, liver, and brain. The findings of histology images of Zn NPs at the dose of 1 g/kg were similar to those of the control. Furthermore, no significant differences were observed in cleaved-caspase-3 expression after exposure to Zn NPs at the dose of 5 g/kg. The results demonstrated that changes in the OS were not related to caspase pathway and the no-observed-adverse-effect level (NOAEL) dose of biogenic Zn NPs in 14-days subacute toxicity study was lower than 1 g/kg.

Probiotic and antioxidant properties of selenium-enriched Lactobacillus brevis LSe isolated from an Iranian traditional dairy product.

The present study was designed to isolate a highly selenium-tolerant lactobacillus strain from an Iranian traditional dairy product named as Spar. Different criteria such as tolerance to the low pH, simulated gastric juice (SGJ), simulated intestinal juice (SIJ) and bile salts tolerance as well as Caco-2 cell adhesion assay were examined to evaluate the probiotic potentials of the selected isolate. Furthermore, the antioxidant properties of the isolate cultivated in medium containing and free of SeO32- ions were evaluated using DPPH scavenging and reducing power assays. The isolate was identified using conventional identification and 16S rDNA gene sequencing methods as Lactobacillus brevis LSe. The obtained results showed that the isolate was able to tolerate high concentration of sodium selenite (3.16mM). By decreasing the pH of the SGJ from 6 to 3, the survival percent of L. brevis LSe was not significantly changed over the time (p>0.05). In addition, the survival percent of the isolate in the SIJ (pH 6 and pH 8) was not statistically altered after 3h, 6h and 24h of incubation (p>0.05). In the presence of bile salts (0.3% and 0.6%) the survival rate of L. brevis LSe was not significantly decreased (p>0.05).L. brevis LSe also demonstrated the satisfactory ability to adhere to Caco-2 cells which were similar to that of the reference strain L. plantarum. The obtained results of antioxidant evaluation showed that L. brevis LSe containing elemental Se exhibited significantly higher radical scavenging ability (36.5±1.31%) and reducing power (OD700, 0.14) than L. brevis LSe cultured in selenite-free medium (p<0.05). To sum up, further investigations should be conducted to merit the probable potential health benefit of Se-enriched L. brevis LSe and its application as Se-containing supplements or fermented foods.

Anti-biofilm activity of biogenic selenium nanoparticles and selenium dioxide against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis.

The aim of the present study was to investigate the anti-biofilm activity of biologically synthesized selenium nanoparticles (Se NPs) against the biofilm produced by clinically isolated bacterial strains compared to that of selenium dioxide. Thirty strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis were isolated from various specimens of the patients hospitalized in different hospitals (Kerman, Iran). Quantification of the biofilm using microtiter plate assay method introduced 30% of S. aureus, 13% of P. aeruginosa and 17% of P. mirabilis isolates as severely adherent strains. Transmission electron micrograph (TEM) of the purified Se NPs (produced by Bacillus sp. MSh-1) showed individual and spherical nano-structure in the size range of 80-220nm. Obtained results of the biofilm formation revealed that selenium nanoparticles inhibited the biofilm of S. aureus, P. aeruginosa, and P. mirabilis by 42%, 34.3%, and 53.4%, respectively, compared to that of the non-treated samples. Effect of temperature and pH on the biofilm formation in the presence of Se NPs and SeO2 was also evaluated.

Antioxidant and cytotoxic effect of biologically synthesized selenium nanoparticles in comparison to selenium dioxide.

The present study was designed to evaluate antioxidant and cytotoxic effect of selenium nanoparticles (Se NPs) biosynthesized by a newly isolated marine bacterial strain Bacillus sp. MSh-1. An organic-aqueous partitioning system was applied for purification of the biogenic Se NPs and the purified Se NPs were then investigated for antioxidant activity using DPPH scavenging activity and reducing power assay. Cytotoxic effect of the biogenic Se NPs and selenium dioxide (SeO2) on MCF-7 cell line was assesed by MTT assay. Tranmission electron micrograph (TEM) of the purified Se NPs showed individual and spherical nanostructure in size range of about 80-220nm. The obtained results showed that, at the same concentration of 200µg/mL, Se NPs and SeO2 represented scavenging activity of 23.1±3.4% and 13.2±3.1%, respectively. However, the data obtained from reducing power assay revealed higher electron-donating activity of SeO2 compared to Se NPs. Higher IC50 of the Se NPs (41.5±0.9µg/mL) compared to SeO2 (6.7±0.8µg/mL) confirmed lower cytotoxicity of the biogenic Se NPs on MCF-7 cell line.