Download Nanotechnology

Bayan Farhan,
Deema Al Zoubi,
Leyan Omat,
Maha Omar,
Yasmeen Abu Sharar.
Nanotechnology as Novel Antimicrobials
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Rising antimicrobial resistance is decreasing
the effectiveness of widely used
antimicrobials[2,3].
Scientists have been investigating several
methods for overcoming antimicrobial
resistance, one of the most novel methods
today is utilizing nanotechnology in
developing antimicrobial nanomaterials and
nano-sized drug carriers[3].
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Nanotechnology is a technology that exploits
the properties of compounds at the nanoscale (1-100nm).
In nanotechnology, we are trying partially to
imitate nature and to build things starting
with atoms.
Nanoparticles can target a bacterial cell
individually which increases the effectiveness
of the antimicrobial agent and decreases
resistance development against it. Some
nanomaterials can also play the role of the
antibiotic agent themselves[8].
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Nanobiotics are nanomaterials which either
show antimicrobial activity by themselves or
enhance the properties of existing
antibiotics[8].
Advantage
Disadvantage
Antimicrobial NPs
Targeted drug delivery via specific
accumulation
Lowered side effects of chemical
antimicrobials
Low antimicrobial resistance
Free antimicrobial agents
Disadvantage No specific accumulation
High side effects of chemical
antimicrobials
High antimicrobial resistance
Controlled drug release
Usual pharmacokinetics of free drugs
Broad therapeutic index
Improved solubility
Low immunosuppression
Low cost
Accumulation of intravenously injected
nanomaterials in tissues and organs
Narrow therapeutic index
Sometimes poor solubility
Immunosuppression
High cost
Absence of nanomaterials in the whole
body
Advantage
High systemic exposure to locally
administrated drugs
Low systemic exposure to locally
administrated drugs
Nanotoxicity (lung, kidney, liver, brain,
germ cell, metabolic, etc.)
Absence of nanotoxicity
Lack of characterization techniques that
are not affected by NPs' properties
Well-established characterization
techniques
Nano particles used in diagnosis and
treatment of diseases like: cancer and
bacterial infections especially after the
presence of antibiotics resistance.
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There are many types of nanoparticles that
we can use it in bacterial infection, like:
1. Ag NP.
2. Au NP.
3. ZnO NP.
But Ag NPs have the most antibacterial effect
against bacteria, viruses and eukaryotic
microorganisms.
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1. Ag NPs can attach to the surface of
bacterial cell membrane and distrub its
functions like: permeability.
2. They are able to penetrate the bacterial cell
and interact with sulfur- and phosphoruscontaining compounds such as DNA.
3. They affect bacterial signal transduction
and inhibit bacterial growth.
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It can float in air might easily penetrate
animal and plant cells causing unknown
effects because of the greater its surface area
to volume ratio.
Nanoparticles have high chemical reactivity
and this results in increased production of
reactive oxygen species including free
radicals that is one of the primary
mechanisms of nanoparticles toxicity
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Klebsiella is a type of Gram-negative bacteria.
It causes different types of infections:
-pneumonia
-bloodstream infections
- wound or surgical site infections
- meningitis.
They are normally found in the human
intestines and human stool (feces).
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Infections commonly occur in healthcare
settings among sick patients whose care
requires devices like ventilators or
intravenous catheters, and patients who are
taking long courses of certain antibiotics.
Klebsiella bacteria have developed
antimicrobial resistance, most recently to the
class of antibiotics known as carbapenems.
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1-Silver carbine complex (SCC23-LTP NPs)
-a broad-spectrum antimicrobial agents
-with low toxicity. (they accumulate in lungs after
nebulization resulting in a controlled release)
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The silver carbene complexe (SCC NPs) were
tested against different pathogens include
Klebsiella pneumoniae and the results show that
it was active against highly resistant bacterial
strains.
2- Silver nanoparticles (Ag NPs )
Size: 43nm , dosage 30 mg/l
used in many food and drug products due to its
good antimicrobial properties.
- Distrubt to the cell membrane and inhibit
bacterial growth.
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The studies talked about the adsorption and
toxicity of SNPs on bacterial species such as
Klebsiella pneumoniae at different pH including
acidic, neutral and alkaline .
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The Maximum adsorption and toxicity was at
acidic pH =5 with 20 c temperature
The minimum adsorption and toxicity was at
basic pH= 9 with same temperature.
The study shows that the bacterial species
was decreased with increase in adsorption of
SNPs.
3- nitric oxide nanoparticle (NO NPS )
Size:10-15 nm
MIC =10 mg/ml in 24 hours
-a broad-spectrum antimicrobial agents
- Alteration of the bacterial membrane (nitrosation of
protein thiols and the nitrosylation of metal centers)
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The studies found that the nitric oxide-releasing
nanoparticle were active against many different
strains of bacteria that were sensitive and
resistant to most commonly used antibiotics
including Klebsiella pneumoniae . (3)
Pseudomonas aeruginosa
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A gram negative bacteria .
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Multi drug resistant .
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The spectrum of diseases caused by this
bacterium continues to expand from urinary
tract infection to septicaemia, and
endocarditis.
Effect of Nanoparticles on
Pseudomonas aeruginosa:
1-Effect of silver nanoparticles on
Pseudomonas aeruginosa:
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Result shows the inhibition zone for all
samples were of approximately 11.6 mm
when the organism was tested against 10 μg
of nanoparticles.
The results were similar in MDR strains and
the susceptible strains.
Gentamicin showed a larger inhibition zone
amongst susceptible strains but there was
aslight reduction in the zone of inhibition
among the MDR strains as compared to the
Ag nanoparticles.
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This shows that the Ag nanoparticles have
antimicrobial activity against the P.aeruginosa
strains .
2-Effect of zinc oxide nanoparticles on
pseudomonas aeruginosa biofilm formation:
What is zinc oxide ?
Zinc oxide nanoparticles (ZnO NPs) are
reported to possess anti-microbial activity.
These particles significantly can reduce the
skin infection, bacterial load and
inflammation in mice .
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ZnO nanoparticle-coated surfaces inhibit
bacterial biofilm formation and increase
antibiotic susceptibility. They showed
hydroxyl radicals, originating from the coated
surface had a main role in anti-biofilm
activity, but its effect is less to remove preformed biofilm.
-Staphylococcus aureus is a gram positive
bacteria, it’s a common cause of many diseases.
-MRSA is a worldwide problem.
-S.aureus bacteria able to produce biofilms if
they were on biomaterial implants like catheters,
artificial joints and heart valves that impede the
entrance of antibiotics .
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Catheters were coated with MgF2
nanoparticles in a uniform layer on both sides
of catheters.
MgF2-coated catheters were investigated for
their ability to reduce the formation of
biofilms.
- Also, they were shown to be relatively
harmless to mammalian cells.
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We conclude that the surface modification of
catheters with MgF2 nanoparticles can
prevent the colonization of bacteria and make
the catheters sterilized while they are in our
bodies.
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Supermagnetic iron oxide nanoparticles
(SPIONs) was tested on biofilms of
gentamicin-resistant staphylococcus aureus.
The results show that SPIONs cause a
significant increase in the percentage of dead
S.aureus.
that the SPOINs must be targeted and
concentrated on the biofilm using an external
magnetic field to give the maximum effect.
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The particles size of nanoparticles should
range from 14-18 nm, and because of their
small sizes; they can penetrate into bacteria
easily.
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In the study of the effect of silver carbine
complexes (SCCs), they were tested against
different strains of bacteria including MRSA.
They used LTP and PEG-PLA as a delivery systems
to encapsulate SCCs.
SCCs complexes has shown antimicrobial activity
against MRSA.
In vivo studies on mice that have pneumonia,
they was effective, they accumulate in lungs after
nebulization resulting in a controlled release of
SCCs at the site of infection, thereby minimizing
the toxicity.
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The concentrations at which these complexes
are effective may decreased with the
administration of consecutive doses.
Also, these complexes are relatively have low
toxicity to human cells which make them
promising alternatives to antibiotics that have
become ineffective as in case of MRSA.