Table 11.1 Bactericidal activity of nanoparticles

Type of

NPs

Bacterial

strains/cells

Proposed mode of

action

Effect caused

Refs.

Interaction with cell barriers

HAPw/n-

ZnO

S. mutans,

Candida

albicans,

S. aureus, and

E. coli

–

Pronounced

bactericidal effect

in S. mutans,

Candida albicans,

S. aureus in

contrast to E. coli

Destruction of the

bacterial cell

membrane

Yu et al. (2014)

Nano-

diamonds

E. coli and

B. subtilis

Formation of

covalent bonds

with adjacent

cellular matrix and

intracellular

proteins

Restricted

enzymatic activity

Disordered

translation

Metabolic

pathways

Apoptosis

Wehling et al.

(2014)

TiO2

–

Adhesion of NPs

with bacterial cell

wall resulted in

increased

membrane

permeability,

ROS, free

hydroxyl radicals,

and hydrogen

peroxide

production.

Degradation of cell

wall and

cytoplasmic

membrane

Intrinsic damage to

the bacterial cell

membrane

Altered

morphology

Inhibited cell

functions

Leaked cellular

(cytoplasmic)

components (viz.,

ions and

micronutrients)

Apoptosis

Cell lysis

Complete

mineralization of

the organism

Gradual

degradation of cell

wall

Foster et al. (2011)

and Joost et al.

(2015)

n-ZnO

E. coli

Adhesion of NPs

with bacterial cell

wall resulted in

ROS production

Damaged cell

membrane

(honeycomb

structure

formation, pit, bit,

or hole formation)

Restricted

enzymatic activity

Leakage of

intracellular

protein

Padmavathy and

Vijayaraghavan

(2011)

(continued)

160

A. Parmar and S. Sharma