Biogenic Silver Nanoparticles: Assessment of Their Cytotoxicity, Genotoxicity and Study of Capping Proteins

Abstract

<jats:p>The development of nanotechnology in the last two decades has led to the use of silver nanoparticles (AgNPs) in various biomedical applications, including antimicrobial, anti-inflammatory, and anticancer therapies. However, the potential of the medical application of AgNPs depends on the safety of their use. In this work, we assessed the in vitro cytotoxicity and genotoxicity of silver nanoparticles and identified biomolecules covering AgNPs synthesized from actinobacterial strain SH11. The cytotoxicity of AgNPs against MCF-7 human breast cancer cell line and murine macrophage cell line RAW 264.7 was studied by MTT assay, cell LDH (lactate dehydrogenase) release, and the measurement of ROS (reactive oxygen species) level while genotoxicity in Salmonella typhimurium cells was testing using the Ames test. The in vitro analysis showed that the tested nanoparticles demonstrated dose-dependent cytotoxicity against RAW 264.6 macrophages and MCF-7 breast cancer cells. Moreover, biosynthesized AgNPs did not show a mutagenic effect of S. typhimurium. The analyses and identification of biomolecules present on the surface of silver nanoparticles showed that they were associated with proteins. The SDS-PAGE (sodium dodecyl sulfate–polyacrylamide gel electrophoresis) analysis revealed the presence of 34 and 43 kDa protein bands. The identification of proteins performed by using LC-MS/MS (liquid chromatography with tandem mass spectrometry) demonstrated their highest homology to bacterial porins. Capping biomolecules of natural origin may be involved in the synthesis process of AgNPs or may be responsible for their stabilization. Moreover, the presence of natural proteins on the surface of bionanoparticles eliminates the postproduction steps of capping which is necessary for chemical synthesis to obtain the stable nanostructures required for application in medicine.</jats:p>

Tannic Acid-Stabilized Silver Nanoparticles Used in Biomedical Application as an Effective Antimelioidosis and Prolonged Efflux Pump Inhibitor against Melioidosis Causative Pathogen

“…The AgNPs colloidal solutions with pH value of 5.94 were measured. Silver nanoparticles (AgNPs) had average hydrodynamic diameters of 101.13 ± 0.85 nm with low polydispersity index (PDI) value (0.20 ± 0.01 nm), indicating high particle homogeneity [ 23 ] ( Figure 2 a) and the zeta potential value of -47.63 ± 5.79 mV revealed the stability and negatively charge of AgNPs [ 24 ] ( Figure 2 b). This zeta potential value indicated that tannic acid contributed to the negative charge distribution.…”

“…From Dynamic Light Scattering (DLS) measurement, we found that the hydrodynamic diameter of AgNPs was greater than the average size observed from TEM due to the solvent and stabilizer layers present around the AgNPs’ surface [ 34 ]. The negative zeta potential of −43.9 mV ( Figure 2 b) proved the high stability of AgNPs due to the electrostatic repulsion of NPs in the solution [ 24 , 35 , 36 ].…”

Green Synthesized Silver Nanoparticles: Antibacterial and Anticancer Activities, Biocompatibility, and Analyses of Surface-Attached Proteins

“…However, differences in the nanoparticle size and charge might be related to strain specificity, growth conditions of strain, and conditions used during the synthesis process (Kupryashina et al, 2013;Mohanta and Behera, 2014;Rai et al, 2016). Some subtle differences have been observed even in the same isolate (Wypij et al, 2017(Wypij et al, , 2020. The FTIR bands observed in region 3,430 cm −1 is characteristic for vibrations of hydroxyl and amino groups (Shanmugaiah et al, 2015;Qayyum et al, 2017;Wypij et al, 2018a;Oves et al, 2019).…”

“…The AgNPs synthesized by peel extract of Citrus sinensis were capped by three different proteins with aspartic-type endopeptidase, GSH S-transferase, and oxalate oxidase activities (Barros et al, 2018). Recently, Wypij et al (2020) separated proteins associated with AgNPs from actinobacteria using SDS-PAGE and found three protein bands that showed the highest homology to porins previously described in Gramnegative bacteria. Similarly, in the present work SDS-PAGE analysis showed the presence of five proteins bands at a molecular weight between 31.7 and 280.9 kDa.…”

Nanolayered Metal Phosphates as Biocompatible Reservoirs for Antimicrobial Silver Nanoparticles

“…Furthermore, silver is reported for its ability to reduce infections in the treatment of burned areas [ 37 ]. When silver is prepared as nanoparticles, it provides excellent antimicrobial effects [ 38 , 39 ].…”