Antibacterial effect of silver nanoparticles prepared in bipolymers at moderate temperature

Enhanced cytotoxic activity of AgNPs on retinoblastoma Y79 cell lines synthesised using marine seaweed Turbinaria ornata

Retinoblastoma is the most common intraocular malignancy basically occurs among children below five. Certain ocular treatments such as surgery, radiation therapy and chemotherapy are more likely to cause side effects. Here, a rapid method of synthesising silver nanoparticles (AgNPs) from the brown seaweed Turbinaria ornata and its cytotoxic efficacy against the retinoblastoma Y79 cell lines was studied. The AgNPs synthesis was determined by Ultraviolet-visible spectroscopy and was further characterised by X-ray diffraction, High-resolution transmission electron microscopy, zeta potential, Energy-dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectrum and inductively coupled plasma-mass spectroscopy techniques. The synthesised AgNPs were found to be very stable and finely dispersed. The total phenolic content of the synthesised AgNPs was estimated at 43±2.52 mg/g gallic acid equivalent and the nanoparticles exhibited good scavenging activity analysed by 2, 2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) assay. Moreover, cytotoxicity of synthesised AgNPs against in vitro retinoblastoma Y79 cell lines showed a dose-dependent response with an inhibitory concentration (IC₅₀) of 10.5 µg/mL. These results suggest that AgNPs could be a promising anticancer agent with enhanced activity in ocular treatment.

Development of porous and antimicrobial CTS–PEG–HAP–ZnO nano-composites for bone tissue engineering

We have developed porous, antimicrobial, biodegradable, and pH and blood compatible CTS–PEG–HAP–ZnO nanocomposites having good mechanical properties and osteoblast cell proliferation abilities to mimic cancellous bone in bone tissue engineering.

Stirring time effect of silver nanoparticles prepared in glutathione mediated by green method

Background

This study aims to investigate the influence of different stirring time for synthesis of silver nanoparticles in glutathione (GSH) aqueous solution. The silver nanoparticles (Ag-NPs) were prepared by green synthesis method using GSH as reducing agent and stabilizer, under moderate temperature at different stirring times. Silver nitrate (AgNO₃) was taken as the metal precursor while Ag-NPs were prepared in the over reaction time.

Results

Formation of Ag-NPs was determined by UV–vis spectroscopy where surface plasmon absorption maxima can be observed at 344–354 nm from the UV–vis spectrum. The synthesized nanoparticles were also characterized by X-ray diffraction (XRD). The peaks in the XRD pattern confirmed that the Ag-NPs possessed a face-centered cubic and peaks of contaminated crystalline phases were unable to be located. Transmission electron microscopy (TEM) revealed that Ag-NPs synthesized were in spherical shape. Zeta potential results indicate that the stability of the Ag-NPs is increases at the 72 h stirring time of reaction comparison to GSH. The Fourier transform infrared (FT-IR) spectrum suggested the complexation present between GSH and Ag-NPs. The use of green chemistry reagents, such as peptide, provides green and economic features to this work.

Conclusions

Ag-NPs were successfully synthesized in GSH aqueous solution under moderate temperature at different stirring times. The study clearly showed that the Ag-NPs synthesized in the long times of stirring, thus, the kinetic of GSH reaction is very slow. TEM results shows that with the increase of stirring times the mean particle size of Ag-NPs become increases. The FT-IR spectrum suggested the complexation present between GSH and Ag-NPs. These suggest that Ag-NPs can be employed as an effective bacteria inhibitor and can be applied in medical field.