Green synthesis of silver nanoparticles using Arbutus andrachne leaf extract and its antimicrobial activity

Purpose: To synthesize silver nanoparticles (AgNPs) of Arbutus andrachne leaf water extract (LE) and to evaluate the antimicrobial activity of both LE and AgNPs. Methods: The synthesized AgNPs were characterized using the following techniques: ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) analysis, and analysis of particle size (PS) and zeta potential (ZP). The antimicrobial activities of LE and NPs were assessed by Kirby-Bauer disc diffusion (DD) and broth microdilution (MD) methods according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI). LE and AgNPs were examined against fresh cultures of four Gram-positive and five Gram-negative bacteria, and three yeast strains. Results: AgNPs were successfully synthesized and characterized using Arbutus andrachne LE. The AgNPs showed moderate antibacterial activity against Staphylococcus aureus ATCC 6538p, S. epidermidis ATCC 12228, Escherichia coli ATCC 29998, Klebsiella pnemoniae ATCC 13883 and Pseudomonas aeruginosa ATCC 27853, and also antifungal activity against Candida albicans ATCC 10239 and C. krusei ATCC 6258. Conclusions: Due to the potent activity of AgNPs against Gram-positive and Gram-negative bacteria, and yeast strains, it is suggested that AgNPs are potential broad spectrum antimicrobial agents.

Development of docetaxel and alendronate-loaded chitosan-conjugated polylactide-co-glycolide nanoparticles: In vitro characterization in osteosarcoma cells

Purpose: To develop docetaxel (DTX)- and alendronate (ALN)-loaded, chitosan (CS)-conjugated polylactide- co-glycolide (PLGA) nanoparticles (NPs) to increase therapeutic efficacy in osteosarcoma cells. Methods: Drug-loaded PLGA NPs were prepared by nanoprecipitation and chemically conjugated by the carboxylic group of PLGA to the amine-bearing CS polymer. The nanocarrier was characterized by dynamic light scattering, transmission electron microscopy, scanning electron microscopy, and differential scanning calorimetry as well as by in vitro drug release and cell culture studies. Results: NP size was within the tumour targeting range (~200 nm) with an effective positive charge (20 mV), thus increasing cellular uptake efficiency. Morphological analysis revealed clear spherical particles with uniform dispersion. The NPs exhibited identical sustained release kinetics for both DTX and ALN. CS-conjugated PLGA with dual-drug-loaded (DTX and AL) NPs showed typical time-dependent cellular uptake and also displayed superior cytotoxicity in MG-63 cells compared with blank NPs, which were safe and biocompatible. Conclusion: Combined loading of DTX and ALN in NPs increased the therapeutic efficacy of the formulation for osteosarcoma treatment, thus indicating the potential benefit of a combinatorial drug regimen using nanocarriers for effective treatment of osteosarcoma.