NANOTECHNOLOGY

NANOTECHNOLOGY
BY
DR. KEN EZEALISIJI

Presentation outline
• INTRODUCTION
• DEFINITION
• NANOMATERIALS
• NANOFABRICATION
• APPLICATION
• NANOTOXICITY
• CONCLUSION

Introduction
Nanotechnology products are already around
us than we can imagine, ranging from the
components of your cell phone, optical
sensors of your computers etc
Nanoparticles can only be seen with modern
Electron microscope e.g. Transmission
electron microscope, Scanning electron
microscope and Photon correlation
microscope (DLS)
One can now appreciate how small a
nanoparticle is

What is nanotechnology
Nanotechnology is the art and science of manipulating matter at the Nanoscale.
It deals with the design, manipulation and construction of structures and
frameworks of the order or lower than 100nm by controlling the shape and size
properties, reactions and usefulness (Palanivel 2004).
 This art can be employed across many fields such as chemistry, biology, physics,
material science and engineering.
Nanotechnology have enjoyed great application in healthcare (Siddhartha and
Debrata 2009), engineering (Narendra and Uday 2014), and water treatment.

Nanoparticles
Organic Nanoparticles
e.g. Micelles, Dendrimers, Quantum dots, Fullerenes and
Liposomes
Inorganic Nanoparticles
Noble metal NP e.g. Gold and Silver; Magnetic NP, Metal oxide NP
e.g. ZnOnps, TiONPs, CuONPs
Nano-emulsions
(usually in transdermal patch)
Solid Lipid Nanoparticles (SLN)
Nano scaffolds (Graphenes)

The Two Approaches to Nanoparticle Synthesis

Microorganisms that can be used for the
synthesis of nanoparticles includes but not
limited to:
 Klebsiella pneumonia
 Lactobacillus spp
 Corynebacterium spp
 Pseudomonas stuzeri
 Fusarium oxysporum(fungi)
 Thermomonospora sp(actinomycetes) This
aspect is more of Biotechnology ( Note the
difference)

Plant Nanoparticle Size (nm) Shape
Aloe vera Ag & Au 50-350 Spherical,
triangular
Camelia sinensis Ag & Au 30-40 Spherical,
triangular,
irregular
Curcuma longa Pd 10-15 Spherical
Eucalyptus macrocarpa Au 20-100 Spherical,
triangular,

Plant Nanoparticle Size (nm) Shape
Mangifera indica Ag 20 Spherical,
triangular,
hexagonal
Psidium guajava Au 25-30 Spherical,
triangular
Terminalia catappa Au 10-35 Spherical
Pyrus spp Au 200-500 Triangular,
hexagonal

APPLICATION OF NANOTECHNOLOGY IN
MEDICINE
Nanomedicine
It is defined as medical application of
nanotechnology.
The only problem envisaged in nano-
medicine is that of toxicological
concerns of nano-scale materials.
 Nano-materials when functionalized
can be made to perform certain tasks
such as diagnosis (Imaging), therapy,
and drug delivery vehicles.

Drugs have been delivered to specific cells using
nanoparticles thereby reducing problem of aqueous
insolubility as well as first pass effect.
Active principle are delivered/deposited only around
the pathological site in very low dose, reducing side
effects, consumption and treatment expenses
 Nano-scale devices are less invasive (can be given as
a transdermal patches or inhaler).
 Protocol here needs efficient encapsulation of drugs,
good delivery of drug direct to the target site and
successful drug release.
Targeted Nano-Drug delivery

Nano drug delivery is known to:
[a] Improve the Pharmacokinetics of drugs
[b] Improve the bio distribution of drugs
[c] Ensure the passage of drugs through cell
membranes and cytoplasm (poorly water
soluble drugs).
[d] Triggered response (pH or Temperature) is
very beneficial in drug delivery.
•

The size of the particles allows them to penetrate
and concentrate around morbid cells.
The high surface area of nanoparticles can be
functionalized during the course of synthesis, so as
to give it multiple arms which can seek out and
bind to certain tumour cells.
Cancer cells may be detected and eliminated
before they form tumours
Cancer tumours may be destroyed with minimal
damage to healthy tissue and organs
Cancer treatment using Nanotechnology

Some of these nanotechnology-based drugs are
commercially available:
[a] Araxane: (FDA approved) for breast cancer,
this contain nanoparticle albumin bound
Paclitaxel.
[b] Doxil : (FDA approved) for HIV-related
Kaposi`s Sarcoma. (Encased in Liposomes)
[c] Onivyde, This is encapsulated Irinotecan
for metastatic cancer.

Mechanism of Nano-drug delivery
 Researchers are developing graphene
strips to deliver different drugs to specific
regions of cancer cells.
 When the graphene strip reaches the
cancer cell one drug seperates from the
graphene and attacks the cell membrane
while the graphene strip enters the cell and
delivers the second drug to the cell
nucleus.
 Mesoporous silica nanoparticles acts as
cargo.

Imaging
The use of nanoparticle contrast agents has
improved images such as ultrasound and MRI.
Nano particles have been used to visualize (by
contrast) blood pooling (during stroke in the
brain), ischemia and atherosclerosis.
Light emitting quantum dots are used with MRI
(Magnetic Resonance Imaging) to give great
image of tumor site.
Nanoparticles of Cadmium, Selenium (quantum
dots) are known to glow when exposed to UV-
Light. This helps surgeons when manipulating
through tumors.

Sensing
Inert mesoporous silica nanoparticles can take
up large number of dye stuffs, deliver them to
sites and this can be captured through snap
shots.
Gold nanoparticles tagged with short segment
of DNA can be used for detection of genetic
sequence in a sample.
Surgeries with artheroscopes are performed
with nano sensors (with lights). This helps
surgery to be done with fewer invasions.

Tissue engineering
The tissue engineering aspect helps
reproduce or repair or reshape damaged
tissue using suitable nanomaterial-based
scaffolds and growth factors: this may replace
convectional organ transplants.

Antimicrobial Agents
• Silver nanoparticles (used in hospital
beddings to combat nosocomial
infections, water treatment etc. Dental
care and drug delivery)
• Gold nanoparticles (antimicrobial and
cancer treatment)
• Metal oxides nanoparticles (ZnONPs, TiO
and CuONPs).

Nanotoxicity: "The dose makes the poison” but this saying is
refined in the case of nanoparticle.
The toxicity of NPs is dependent on:
their size,
shape,
surface chemistry,
dissolution and degree of aggregation.

Toxicity of nanoparticles is majorly size
dependent.
The smaller the size of these materials
the larger the surface area
This directly influences the interaction
of these materials with biological
components; their uptake, distribution
and bioavailability in the body is altered
inadvertently causing toxicities.
CuO NPs have been found to be more
toxic than the bulk material (Cu as an
element).
The degree of dissolution of CuO NPs
depends on the temperature and pH of
the system.
It's use has been associated with
cytotoxicity, genotoxicity, oxidative
stress induction and DNA damage even
at low doses in Eukaryotes.

CONCLUSION
•As a conclusion to this topic I would like to say that Nanotechnology
is a brand new technology that has just began.
•It is a revolutionary science that will change all what we knew before.
•The future that we were watching just in science fiction movies will in
the near future be real (Teleportation research is on going).
•This new technology will first of all, keep us healthy because of
nanorobots that will repair every damage that we have in our body.

NANOTECHNOLOGY

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