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This study was designed to evaluate and compare the stability, antioxidant and anticancer activities of selenium nanoparticles (SeNPs) decorated with different molecular weight (MW) of chitosan (CS) (1500 Da, 48 kDa, 510 kDa). The size range of well‐dispersed SeNPs was effectively controlled by I− first and then coated with CS. The morphology, size and surface charge of generated SeNPs were characterised by several technologies. Fourier transform infrared spectroscopy was used to investigate the relationship between SeNPs and CS. SeNPs decorated with CS (510 kDa) can keep stable for more than 45 days. As observed from the results of a simple photometric system, the antioxidant activities of decorated SeNPs were enhanced compared to undecorated SeNPs. SeNPs coated with higher MW of CS (510 kDa) showed the strongest antioxidant activities. Moreover, the treatments of SeNPs decorated with CS inhibited the growth of HepG2 cells in a time‐ and dose‐dependent manner. The proposed results demonstrated the critical roles of the MW of CS on the stability, antioxidant and anticancer properties of CS‐coated SeNPs, which provided an important design cue for future applications of functional foods and additives. [ABSTRACT FROM AUTHOR]

Synthesis of iron nanoparticles (INPs) with a biocompatible coating usually is a multistep process which requires harsh, special and protected reaction conditions. In the current experiment, the authors used Xanthomonas campestris cells to develop a facile method for fabrication of biocompatible INPs. Bacterial cells were supplied with ferric citrate as an iron precursor. Transmission electron microscopy micrographs exhibited that xanthan gum‐coated INPs are synthesised and deposited on the surface of X. campestris cells and produced nanoparticles were 20–80 nm in diameter with 41.7 nm mean particle size. Xanthan gum coating with about 7 nm thickness formed a clear hollow around each nanoparticle. According to thermogravimetric analysis, the coating was about 13.4% of the total INPs weight. Prepared particles had a zeta potential of −114 mv which is an ideal surface charge to make particles colloidally stable in aqueous matrixes. Xanthan gum‐coated INPs were non‐crystalline with low saturation magnetisation value of about 0.26 emu/g. [ABSTRACT FROM AUTHOR]

This study investigated the cellular uptake of fluorescein isothiocyanate‐labelled mesoporous silica nanoparticles (FITC‐MSNs), amine‐functionalised FITC‐MSNs (AP‐FITC‐MSNs) and their gallic acid (GA)‐loaded counterparts. Mesoporous silica nanoparticles were labelled with fluorescein isothiocyanate, functionalised by 3‐aminopropyltriethoxysilane (APTES) (AP‐FITC‐MSNs) and then loaded by GA. All nanoparticles were characterised by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, and X‐ray diffraction. The cytotoxicity of different concentrations of dyed nanoparticles was investigated using (3‐(4,5‐trihydroxybenzoic acid, dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay and flow cytometry. TEM images showed that the average particle sizes of FITC‐MSNs and AP‐FITC‐MSNs were about 100 and 110 nm, respectively. These nanoparticles were internalised by Caco‐2 cells, accumulated and dispersed into the cytoplasm, nucleus, and subcellular organelles. Nanoparticles containing GA clearly decreased the viability of cells. FITC‐MSNs showed no toxicity on Caco‐2 cells at concentrations of ≤50 µg/ml. Functionalisation of FITC‐MSNs using APTES decreased toxicity effects on the cells. It was found that FITC‐MSNs can be applied at low concentrations as a marker in the cells. In addition, AP‐FITC‐MSNs showed better biocompatibility with Caco‐2 cells than FITC‐MSNs, because of their positive surface charges. [ABSTRACT FROM AUTHOR]