Application of Nanotechnology in Diagnosis and Therapeutics
429
involved in certain gene expression and functioning of pro inflammatory cytokines.
Autophagy is another anti-cancer mechanism followed by AgNPs. It causes critical
cellular damage by NPs and elevated autophagy promotes cell death (Zhang et al.
2016).
Silver NPs are frequently used in antiseptic creams due to its wound healing
properties. It also shows a broad biocidial activity against the microorganisms by
disrupting their unicellular membrane thus disrupting their enzymatic activities. The
antimicrobial activity of AgNPs is very beneficial. They act on bacteria by forming
pits in the cellular membrane of the microorganism. This causes structural changes
and increases membrane permeability and cell death. Another proposed mechanism
of cell death is the formation of free radicals by the silver NPs. The electron spin
resonance spectroscopy studies suggest that free radicals formed by the AgNPs have
the ability to damage the cell membrane and make it porous which ultimately leads
to death of bacteria (Zhang et al. 2016).
The biosynthesized silver NPs are also utilized for the localization of drug
molecules inside the cell. They are identified by bright red florescence. Nano silver
helps in bioimaging because of its plasmonic properties. It replaces the fluorescent
dyes and do not undergo photobleaching. The plasmonic nature of nanosilver can
also be used to destroy the unwanted cells (Zhang et al. 2016).
Nowadays, clinical diagnostics strongly rely on the identification of biomarker
proteins for disease characterization. The antigens and antibodies are used for molecular recognition in protein biosensening. The metal NPs helps in enhancing the
signals in protein detection schemes (Zhang et al. 2016). It is beneficial using the
nanostructures in drug delivery systems. Silver NPs are efficient in gastrointestinal
delivery of the anti-inflammation drugs.
Another promising advantage of silver NPs in the area of therapeutics is in formation of silver-impregnated catheters. Central venous catheters (CVCs) are regularly
used in the hospitals. It has potential infective complications especially, cathetersrelated bloodstream infections. So to avoid these types of infections antibioticimpregnated catheters were used. But the problem with antibiotic-impregnated
catheters was that it can eventually lead to bacterial resistance. Now a new generation of silver-impregnated catheters has replaced the antibiotic ones. It is based
on the use of inorganic silver powder, on which silver ions are bonded with an inert
ceramic zeolite. In the comparative studies between silver-impregnated catheters and
other catheters it was observed that there were lower bloodstream infections in case
of silver-impregnated catheters. There was significantly lower colonization rate in
the silver-impregnated CVCs (Wong and Liu 2010). The tip colonization of coagulase negative staphylococci was also less in them. Hence all these properties of these
catheters made them used increasingly in the medical field. Ventricular drainage
catheters are used in the intensive care patients of acute occlusive hydrocephalus.
But the complication with this is the bacterial colonization due to external cerebrospinal fluid (CSF) drainage, resulting in ventriculomeningitis and encephalitis.
The silver-impregnated ventricular catheters were the important finding for the neurological and neurosurgical patients requiring external CSF drainage. The scientists
observed that the CSF cultures performed at least three times a week showed 25%
429
involved in certain gene expression and functioning of pro inflammatory cytokines.
Autophagy is another anti-cancer mechanism followed by AgNPs. It causes critical
cellular damage by NPs and elevated autophagy promotes cell death (Zhang et al.
2016).
Silver NPs are frequently used in antiseptic creams due to its wound healing
properties. It also shows a broad biocidial activity against the microorganisms by
disrupting their unicellular membrane thus disrupting their enzymatic activities. The
antimicrobial activity of AgNPs is very beneficial. They act on bacteria by forming
pits in the cellular membrane of the microorganism. This causes structural changes
and increases membrane permeability and cell death. Another proposed mechanism
of cell death is the formation of free radicals by the silver NPs. The electron spin
resonance spectroscopy studies suggest that free radicals formed by the AgNPs have
the ability to damage the cell membrane and make it porous which ultimately leads
to death of bacteria (Zhang et al. 2016).
The biosynthesized silver NPs are also utilized for the localization of drug
molecules inside the cell. They are identified by bright red florescence. Nano silver
helps in bioimaging because of its plasmonic properties. It replaces the fluorescent
dyes and do not undergo photobleaching. The plasmonic nature of nanosilver can
also be used to destroy the unwanted cells (Zhang et al. 2016).
Nowadays, clinical diagnostics strongly rely on the identification of biomarker
proteins for disease characterization. The antigens and antibodies are used for molecular recognition in protein biosensening. The metal NPs helps in enhancing the
signals in protein detection schemes (Zhang et al. 2016). It is beneficial using the
nanostructures in drug delivery systems. Silver NPs are efficient in gastrointestinal
delivery of the anti-inflammation drugs.
Another promising advantage of silver NPs in the area of therapeutics is in formation of silver-impregnated catheters. Central venous catheters (CVCs) are regularly
used in the hospitals. It has potential infective complications especially, cathetersrelated bloodstream infections. So to avoid these types of infections antibioticimpregnated catheters were used. But the problem with antibiotic-impregnated
catheters was that it can eventually lead to bacterial resistance. Now a new generation of silver-impregnated catheters has replaced the antibiotic ones. It is based
on the use of inorganic silver powder, on which silver ions are bonded with an inert
ceramic zeolite. In the comparative studies between silver-impregnated catheters and
other catheters it was observed that there were lower bloodstream infections in case
of silver-impregnated catheters. There was significantly lower colonization rate in
the silver-impregnated CVCs (Wong and Liu 2010). The tip colonization of coagulase negative staphylococci was also less in them. Hence all these properties of these
catheters made them used increasingly in the medical field. Ventricular drainage
catheters are used in the intensive care patients of acute occlusive hydrocephalus.
But the complication with this is the bacterial colonization due to external cerebrospinal fluid (CSF) drainage, resulting in ventriculomeningitis and encephalitis.
The silver-impregnated ventricular catheters were the important finding for the neurological and neurosurgical patients requiring external CSF drainage. The scientists
observed that the CSF cultures performed at least three times a week showed 25%