Evaluation of cytotoxicity, immune compatibility and antibacterial activity of biogenic silver nanoparticles.

M Składanowski,K Rudnicka,H Dahm,M Rai,P Golinska

doi:10.1007/s00430-016-0477-7

Abstract

The study was focused on assessment of antibacterial activity, cytotoxicity and immune compatibility of biogenic silver nanoparticles (AgNPs) synthesized from Streptomyces sp. NH28 strain. Nanoparticles were biosynthesized and characterized by UV–Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, nanoparticle tracking analysis system and zeta potential. Antibacterial activity was tested against Gram-positive and Gram-negative bacteria; minimal inhibitory concentration was recorded. Cytotoxicity was estimated using L929 mouse fibroblasts via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Biocompatibility of AgNPs was performed using THP1-XBlue™ cells. Biogenic AgNPs presented high antibacterial activity against all tested bacteria. Minimum inhibitory concentration of AgNPs against bacterial cells was found to be in range of 1.25–10 μg/mL. Silver nanoparticles did not show any harmful interaction to mouse fibroblast cell line, and no activation of nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) cells was observed at concentration below 10 µg/mL. The half-maximal inhibitory concentration (IC50) value was established at 64.5 μg/mL. Biological synthesis of silver can be used as an effective system for formation of metal nanoparticles. Biosynthesized AgNPs can be used as an antibacterial agent, which can be safe for eukaryotic cells.

Highlights

Nanotechnology deals with the development and utilization of structures and devices with organizational features at the intermediate scale between individual molecules and about 100 nm
The presence of biosynthesized silver nanoparticles was confirmed by UV–Vis spectrophotometer analysis, which revealed absorbance peak at wavelength of 421 nm (Fig. 1a), and Transmission electron microscopy (TEM) analysis, which showed polydispersed and spherical in shape nanoparticles with size range of 4.2– 65 nm (±9.7 nm), mean size of 19.9 nm (±13 nm)
Fourier transform infrared (FTIR) studies of AgNPs revealed seven peaks at 3471, 3195, 2969, 2357, 1673, 1467 and 1158 cm−1, which can refer to possible presence of proteins over the surface of biosynthesized AgNPs (Fig. 2a)

Summary

Introduction

Nanotechnology deals with the development and utilization of structures and devices with organizational features at the intermediate scale between individual molecules and about 100 nm. Attention is pointed for synthesis of nanoparticles (NPs) from noble metals like gold, silver, zinc or platinum with further applications in science and life [1]. Biosynthesized nanoparticles are less toxic to chemical equivalent and highly stable because of presence of proteins and cost-effective [2]. This leads many researchers to discover new methods for synthesis of nanoparticles by using organisms such as bacteria, fungi or plants. Silver nanoparticles (AgNPs) have gained attention due to antibacterial activity including multidrug resistance (MDR) microorganisms [1, 3] and Mycobacterium tuberculosis [4]. Biogenic silver nanoparticles have shown activity against viruses such as human immunodeficiency virus type 1 (HIV-1) or Herpex sp. [5] or antileukemia [6] and anticancer [7] properties

Methods

Results

Conclusion