Selective Synthesis of Silver Nanoparticles onto Potassium Hexaniobate: Structural Organisation with Bactericidal Properties

Advances in Using Nanotechnology Structuring Approaches for Improving Food Packaging

Recent advances in food packaging materials largely rely on nanotechnology structuring. Owing to several unique properties of nanostructures that are lacking in their bulk forms, the incorporation of nanostructures into packaging materials has greatly improved the performance and enriched the functionalities of these materials. This review focuses on the functions and applications of widely studied nanostructures for developing novel food packaging materials. Nanostructures that offer antimicrobial activity, enhance mechanical and barrier properties, and monitor food product freshness are discussed and compared. Furthermore, the safety and potential toxicity of nanostructures in food products are evaluated by summarizing the migration activity of nanostructures to different food systems and discussing the metabolism of nanostructures at the cellular level and in animal models.

Biomolecular corona formation: nature and bactericidal impact on surface-modified silica nanoparticles

Biological fluids contain a plethora of different components that can coat nanoparticle's surface and critically affect their interaction with living systems. The recent literature has focused efforts on understanding the overall protein role in this nanoparticle's coating (commonly called a protein corona) without considering other components' influence. Here, we report a protocol to study the relationship between biological fluid components excluding proteins (referred to as a biomolecular corona) and nanoparticles. For this purpose, functionalized silica nanoparticles were duly synthesized to experimentally investigate the extent of biomolecular corona adsorption over different surfaces. This adsorption was directly correlated with the silica surface chemical constitution, while the extent of biomolecular corona coating affected the overall surface charge and the colloidal stability of the functionalized nanoparticles. In addition, the bactericidal properties of biomolecular corona-coated nanoparticles were tested against two medically relevant bacteria (Escherichia coli and Staphylococcus aureus). Biological results indicated that the presence and the extent of the biomolecular corona affect the bactericidal properties of the nanoparticles.

Tailored silica-antibiotic nanoparticles: overcoming bacterial resistance with low cytotoxicity

New and more aggressive antibiotic resistant bacteria arise at an alarming rate and represent an ever-growing challenge to global health care systems. Consequently, the development of new antimicrobial agents is required to overcome the inefficiency of conventional antibiotics and bypass treatment limitations related to these pathologies. In this study, we present a synthesis protocol, which was able to entrap tetracycline antibiotic into silica nanospheres. Bactericidal efficacy of these structures was tested against bacteria that were susceptible and resistant to antibiotics. For nonresistant bacteria, our composite had bactericidal efficiency comparable to that of free-tetracycline. On the other hand, the synthesized composites were able to avoid bacterial growth of resistant bacteria while free-tetracycline has shown no significant bactericidal effect. Finally, we have investigated the cytotoxicity of these nanoparticles against mammalian cells to check any possible poisoning effect. It was found that these nanospheres are not apoptosis-inducers and only a reduction on the cell replication rate was seen when compared to the control without nanoparticles.