Potential Risk of Nanotechnology.

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CHAPTER 14

• Potential Risk of Nanotechnology.

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GROUP MEMBERS

• Azmi Bin Hassan
• Mohd Nazih Bin Jaafar
• Mohd Farid Bin Saiman
• Mohd Azzim Bin Nordin
• Mohd Faiz Bin Mohd Fuad
• Mohd Fikri Bin Omar
• Mohd Azamudin Bin Abdul Aziz

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AGENDA
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Introduction

• Nanotechnology
• Nanotechnology is the understanding and control
  of matter at dimensions of roughly 1 to 100
  nanometers
• Nanotechnology involves imaging, measuring,
  modeling, and manipulating matter in this scale
• Nanotechnology may be able to create many new
  materials and devices with a vast range
  of applications, such as in medicine, electronics,
  biomaterials and energy production.
• Humans are exposed to airborne nanomaterials in
  daily life, such as nanoparticles found in smoke,
  drugs, paints, cosmetics, soaps, shampoos,
  detergents, sunscreens, tennis rackets, video
  screens, coatings, catalysts, concrete.

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Nanostructured material uptake by the human
body and nanotoxicity
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1. Respiratory System
2. Skin
3 WAYS NANOMATERIALS UPTAKE BY HUMAN BODY
3. Ingestion
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• Exposure through respiratory system
• Inhalation of nanoparticles leads to deposition
  of nanoparticles in respiratory tract and lungs.
• Caused lung-related disease. E.g. asthma,
  bronchitis, lung cancer, pneumonia etc.
• Translocation of nanomaterials therefore could
  lead to brain.

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• Exposure through skin
• Nanoparticles may penetrate into sweat glands and
  hair follicles.
• Skin exposure to cosmetics, sunscreens and dusts
  resulted in accumulation of nanoparticles.
• Baroli et al. reported that metallic
  nanoparticles smaller than 10nm could penetrate
  the hair follicle and stratum corneum and
  sometimes reach the viable epidermis.
• However, metallic nanoparticles unable to
  permeate the skin.

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• Exposure through Ingestion
• Exposure of nanomaterials into gastrointestinal
  tract can occur after uptake of daily food,
  drinks and medicines.
• Nanoparticles absorbed by any means can cause
  cytotoxicity effects.
• Cytotoxicity means that nanoparticles prevent
  cell division, hinder cell proliferation, damage
  DNA and biological system and lead to cell death
  by biological process called apoptosis.

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• Apoptosis is a process of deliberate cell
  self-destruction in an organism.
• A size dependent study of copper on mice was
  carried by chen etc al. It show that toxicity
  increase as the size of copper decrease.

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• Quantum dots offer surface manipulation and also
  show potential benefit for biomedical research.
• Nanoscale contrast agents show potential
  applications in magnetic resonance (MR) molecular
  imaging for clinical diagnosis.
• Nanoparticles of cadmium telluride (CdTe)
  exhibit strong fluorescence that could be used in
  solid state lighting and biological probing.
• Carbon nanotubes used for drug delivery to
  specific target such as tumor cells. Nanotubes
  filled with magnetic nanoparticles help in
  transporting medicine to target.
• The biocompatibility of such nanomaterials
  remains questionable due to their adverse effect
  on human health.

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BIOCOMPABILITY AND TOXICITY OF
NANOSTRUCTURED MATERIALS
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• A wide variety of nanomaterials, such as a very
  wide variety of man-made nanostructured materials
  such as
• a. Metallic nanoparticles
• b. Quantum dot.
• c. Fullerenes
• d. Carbon nanotubes
• Are being used for industrial applications in
  coatings, cosmetics, pharmaceutical, and
  biomedical products.
• Recent studies have shown that nanostructured
  materials impose significant risks to human
  health.

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1. Nanoparticles

• Nanoparticles, being smaller in size (1100 nm),
  can deposit within the respiratory tract during
  inhalation.
• Once in the lungs, these nanoparticles start
  interacting with different biological systems.The
  inhaled nanoparticles may have toxic effects and
  could lead to lung diseases.
• For example, Amorphous silica is an important
  material for its applications in biomedical
  research because it can be easily produced at low
  cost .
• But, few reports have recently appeared showing
  that amorphous silica may be toxic at relatively
  high doses. Comparatively, a silica-chitosan
  nanocomposite causes less inhibition in cell
  proliferation and less membrane.
• That means, the cytotoxicity of silica to human
  cells could be reduced by using silica with
  chitosan.

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1.Nanoparticles Cont..

• For Fe3O4, Al2O3, and TiO2 had no measurable
  effect on the cells until the concentrations
  reached greater than 200 µg/ml.
• But more 200 µg/ml doses has been found that
  nanostructured TiO2 particles could generate lung
  tumor and pulmonary fibrosis in rats.

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• Fig 1. (A) to (C) images shows the morphology of
  mouse C18-4 spermatogonial stem cells by phase
  contrast microscopy after incubation with
  different types of nanoparticles for 48 h. Fig. A
  is a control specimen, Fig. B silver
  nanoparticles (15 nm Ag, 10 µg/ml), some cells
  retain an intact plasma membrane (arrows),
  indicating apoptosis. For fig C with Aluminum
  nanoparticles (30 nm Al, 10 µg/ml), the cytoplasm
  is clearly observed without apoptosis and
  necrosis.

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2. Fullerenes.

• Fullerenes are a very important class of
  carbonbased nanostructured materials. The most
  common is a buckminsterfullerene (buckyballs),
  C60.

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Fullerenes. Cont..

• C60 itself shows limited solubility in organic
  solvents but its solubility has been increased by
  chemical modification and functionalization,
  therefore, derivatized fullerenes have opened an
  avenue in the field of biological sciences
  including possible use in the pharmaceuticall
  industry.
• For example, C60-containing bilayer lipid
  membranes may be useful in a biosensor.
• In toxicity behavior, Yamago et al. stated when
  used a radiolabeled fullerene with C14 and found
  fast migration, with liver as the major target
  organ. It has been reported that fullerene
  derivatives could even pass through the
  bloodbrain barrier/

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Fullerenes. Cont..

• C60 having the least degree of derivatization was
  more toxic to cells. also shows that the toxicity
  of C60 based materials depends upon the degree of
  surface functionalization.

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Fullerenes. Cont..

• Table 1 Cytotoxicity of fullerene-based
  nanostructured materials.

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3. Carbon Nanotubes.

• CNTs can be prepared into single-walled (SW)-,
  double-walled (DW)-, few-walled (FW), and
  multi-walled (MW) nanotubes.
• Carbon nanotubes (CNTs) are among the strongest
  and stiffest known materials.
• Single-w alled carbon nanotubes (SWCNTs) show
  potential for applications in sensors, drug
  delivery systems, pharmaceutics, electronics,
  photonics, display devices, reinforced
  composites, etc.
• The biocompatibility and toxicity of carbon
  nanotubes has been studied in experimental
  animals and humans.

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Carbon Nanotubes. Cont..

• Liopo et al. stated that single-walled carbon
  nanotubes (SWCNTs) can support neuronal
  attachment and growth by chemical modifications.
• For the toxicity, Sharma et al. examined the
  toxicity of SWCNTs in rat lung epithelial cells.
  Lung epithelial cells (LE cells) were cultured
  with or without SWCNTs and reactive oxygen
  species (ROS) were measured by change in
  fluorescence.
• Exposure to SWCNTs caused oxidative stress in LE
  cells and showed loss of antioxidants.
• When, multiwall carbon nano-onions (MWCNOs) and
  multi-walled carbon nanotubes (MWCNTs) on human
  skin. Shows thats, exposure increased
  apoptosis/necrosis effect.

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Carbon Nanotubes. Cont..

• Fig. 7. Biodistribution histogram of 125I-SWNTols
  (352106 cpm/ml, µ15 g/ml) in mice at eight
  different time intervals.

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4. QUANTUM DOTS

• Quantum dots have been used as a fluorescent
  labeling agents for both in vitro and in vivo
  studies for stem cell labeling, medical imaging ,
  sensors, light-emittingdiodes, in vivo
  imaging,199 200 biological sensing, and
  multiplexing gene analysis.
• Recently, cytotoxicity of quantum dots (QDs) and
  deleterious effects of the labeling procedure on
  human mesenchymal stem cells has been reported.
• The cadmium-based quantum dots (QDs) showed
  cytotoxic effects.
• The CdTe quantum dots induce cell death by
  involving both Cd2 and reactive oxygen species
  (ROS) accompanied by lysosomal enlargement and
  intracellular redistribution

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Toxicity of nanostructured materials to
environment

• Mainly released-diesel exhaust and petroleum
  fueled vehicle.
• Carcinogenic-radiation that is an agent directly
  involved in causing cancer
• Consist 36-44 of the total concentration.

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Cytotoxicity

• Cytotoxicity is the quality of being toxic
  to cell. Examples of toxic agents are a chemical
  substance, an immune cells or some types
  of venom.
• Apoptosis-(multicellular organism- include cell
  shrinkage, nuclear fragmentation, and chromosomal
  DNA fragmentation.)
• Necrosis-(external to the cell or tissue, such as
  infection, toxins, or trauma that can lead to
  fatal.)
• ROS generation-(Reactive oxygen species-oxidative
  stress, ionizing radiation.)
• Plasma membrane damage.
• Cellular senescence-(normal diploid cells lose
  the ability to divide, DNA double strand breaks
  due to toxins.)

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APPROACHES FOR INCREASINGBIOCOMPATIBILITY AND
REDUCINGNANOTOXICITY OF NANOSTRUCTUREDMATERIALS
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What is nanotoxicology

• Nanotoxicology is the study of the toxicity of
  nanomaterials. Because of quantum size effects
  and large surface area to volume ratio,
  nanomaterials have unique properties compared
  with their larger counterparts.
• Nanotoxicology is a branch of bionanoscience
  which deals with the study and application of
  toxicity of nanomaterials.

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• Toxic effects of nanostructured materials could
  be reduced by using different chemical
  approaches.
• Surface treatment and functionalization of
  nanomaterials could help in reducing toxic
  effects on human health.

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Cytotoxicity

• Cytotoxicity of quantum dots depends on
  physicochemical and environmental factors.
• The cytotoxicity of nanomaterials depends upon
  their surface chemistry and surface
  characteristics

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• Cytotoxicity is studied in vitro, which may not
  accurately indicate the comparative toxicity in
  vivo.
• Nanoparticles may have adverse effects on
  biological systems.

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IN VITRO

• In vitro is a studies in experimental biology on
  an organism that isolated from their component
  which will done on the out side, (test tube
  experiment).
• Can be focus on the cell of the organism, so the
  result will be more accurately.

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• But, in in vitro technique there is a few thing
  that must be alert such as the result, because
  sometimes the result will not be same with the
  real situation.

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IN VIVO

• In vivo is a biological studies on a living
  things either partial or dead organism.

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• As example, nowadays there is a in vitro research
  on HIV curing. Which still cannot work on the
  living organism. So in vivo still need to be
  done.

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WHAT ARE THE POTENTIAL ENVIRONMENTAL EFFECTS OF
NANOMATERIALS?
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• Increases in environmental exposure in air, water
  or soil.
• Like other pollutants, they may pass from
  organism to organism.
• Harmful effects on invertebrates and fish,
  including effects on behaviour, reproduction and
  development.

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• The main focus is on micro-organisms and
  invertebrates and studies on fish.
• The hazardous effects include
• Behaviour
• Growth and development
• Inflammatory responses
• Cytotoxic effects.

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How to work safely with nanomaterials?
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Based on particle physics and studies of fine
atmospheric pollutants, the nanoparticle size
range is the range of minimum settling. This
means that once released into air, nanoparticles
will remain airborne for considerable periods of
time. Nanoparticles can be inhaled and will be
collected in all regions of the respiratory
tract about 35 will deposit in the deep region
of the lungs.
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Because they are so small, nanoparticles follow
airstreams more easily than larger particles, so
they will be easily collected and retained in
standard ventilated enclosures such as fume
hoods. In addition, nanoparticles are readily
collected by HEPA filters. Respirators with HEPA
filters will be adequate protection for
nanoparticles in case of spills of large amounts
of material.
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• Working safely with nanomaterials involves
  following standard (MSDS) - preventing
  inhalation, skin contact, and ingestion.
• Many nanomaterials are synthesized in enclosed
  reactors or glove boxes.
• The enclosures are under vacuum or exhaust
  ventilation, which prevent exposure during the
  actual synthesis.
• Inhalation exposure can occur during additional
  processing of materials removed from reactors,
  this processing should be done in fume hoods.
• In addition, maintenance on reactor parts that
  may release residual particles in the air should
  be done in fume hoods.
• Another process, the synthesis of particles using
  sol-gel chemistry, should be carried out in
  ventilated fume hoods or glove boxes.

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