Potential Application of Nanoparticles as Antipathogens - Advanced Materials for Agriculture, Food and Environmental Safety - page 343

nanoparticles is most likely due to disruption of the cell membrane and
oxidative stress in Campylobacter [42].
h e antibacterial potential of zinc oxide (ZnO) nanoparticles (NPs),
compared with conventional ZnO powder, against nine bacterial strains,
mostly food borne including pathogens, was evaluated using qualitative
and quantitative assays. Gram-positive bacteria were found to be more sen-
sitive to ZnO NPs; their disruptive ef ect on bacteria completely exploded
or lysed the cells. Promising results of ZnO NP antibacterial activity sug-
gested its usage in food systems as preservative agent.
12.6 AntiviralpropertiesofNanoparticles
Metal nanoparticles have been proposed as antiviral systems taking advan-
tage of the core material and/or the ligands shell. Silver nanoparticles have
proven to exert antiviral activity against HIV-1 at noncytotoxic concentra-
tions. Silver nanoparticles prevent CD4-dependent virion binding, fusion
and infectivity, acting as an ef ective Virucidal agent for both cell-free virus
and cell-associated virus [61].
Gold nanoparticles have also been explored for their anti-HIV activity.
h e gold nanoparticles coated with multiple copies of an amphiphilic sul-
phate-ended ligand, bind the HIV envelop glycoprotein gp120 and inhibit
the HIV infection of T-cells at nanomolar concentration in vitro .
12.6.1 Silver
Silver in ionic or nanoparticle forms has a high antimicrobial activity and
is therefore widely used for various sterilization purposes including mate-
rials of medical devices and water sterilization. It is well known that sil-
ver ions and silver-based compounds are highly toxic to microorganisms
showing strong biocidal ef ects on as many as 16 species of bacteria, includ-
ing E. coli [62]. h us, silver ions, as an antibacterial component, have been
used in the formulation of dental resin composites and ion-exchange i bers
and in coatings of medical devices. Recently, Tiller and coworkers showed
that hybrids of silver nanoparticles with amphiphilic hyper branched mac-
romolecules exhibit ef ective antimicrobial surface coatings [63].
12.6.2 SeleniumNanoclusters
Surface characterized by selenium nanoparticles or selenium nanoclus-
ters are herein referred to as being “antipathogenic” to the extent that the