deeply into the cellular periphery of the target pathogens from the outside milieu
(Deplanche et al. 2010; Gurunathan et al. 2014).
11.2.2 Morphology and Texture
Morphology or the shape of the NPs is another factor of paradigm importance, which
plays an intricate role in deciding the fate of NP in inducing a bactericidal response.
It became evident from the pertinent literature that NPs having a diverse spatial
geometry/morphology interact with the periplasmic enzymes in a different manner.
These vivid types of interactions can ultimately produce a slightly different level of
damage in bacteria (Cha et al. 2015). In context to this, a study highlighted the effect
of the variedly shaped nanoparticulate system on antibacterial properties (Yu et al.
2014). It was deciphered that the n-ZnO having a pyramidal geometry prevented the
degradation of periplasmic enzymes. The outcomes also suggested that a
photocatalytic activity was produced by these NPs and the underlying mechanism
responsible for it was found to be the obstruction and reconstruction of these
essential enzymes (Wang et al. 2017; Yu et al. 2014).
In
a
similar
approach,
Y2O3-based
prismatic
NPs
were
fabricated
by
Prasannakumar et al. (2015). The efficacy of these NPs in enticing a bactericidal
activity was assessed in two bacterial strains, viz., S. aureus and P. desmolyticum.
The study showed that the prismatic morphology of these NPs helped them to
establish a strong and direct bridging with the bacterial cell wall. This interaction
further resulted in the breakdown of the bacterial cell membrane, thus finally leading
to cell lysis and apoptosis (Prasannakumar et al. 2015). Actis et al. studied the effect
of AgNP geometry on the survival and growth rate of S. aureus (Actis et al. 2015). It
was seen that among all the fabricated AgNPs, cubical-shaped NPs showed maxi-
mum bactericidal activity due to it its high surface area to the volume ratio and
facade reactivity (Actis et al. 2015; Wang et al. 2017). Apart from the broad research
in regard to the impacts of various NP attributes on bacterial cells, few investigations
have highlighted the impact of texture. It has been witnessed that an increase in the
roughness of the NPs surface leads to a significant enhancement in the adsorption of
bacterial proteins. This escalation in the bacterial protein adsorption on the corona of
NPs results in a diminished bacterial adhesion (Ben-Sasson et al. 2013; Sukhorukova
et al. 2015).
11.2.3 Surface Charge Density
In recent studies, it has been repeatedly shown that the surface charge density also
known as zeta potential has an adverse effect on the adhesive property of the NPs.
The highly charged positive particles tend to attach them more firmly to the
negatively charged bacterial cell wall. On the other hand, in case of negatively
charged NPs, a complete paradoxical scenario is seen. This point was highlighted
in a study where two types of Mg-based NPs, viz., Mg (OH)2_MgCl and Mg
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