DDT 26 - Nanoparticles 1: Exposure, uptake and clearance Flashcards
what are the size ranges of aerosols
Aerosols range from micrometer sized particles (dust and fine dust) down to nanoparticles (ultrafine dust).
air quality index level 0-50 means ..
good - satisfactory and air pollution poses no risk
air quality index level 101-150 means
unhealthy for sensitive groups - these groups may face health effects
air quality index level 51-100 means
moderate - acceptable but may pose as a health concern for a very small unusually sensitive group of people
air quality index levels 151-200 means…
unhealthy - everyone faces health effects and sensitive may experience serious health effects
air quality index levels 201 - 300…
very unhealthy - emergency conditions
air quality index levels 301- - 500 means …
hazardous -
what is the surface area of the lung and how many nano particles are inhaled in the lungs each day
70-100 m2
10^10-10^12 fine particles deposit in the lung/day
average size of nanoparticles in lungs
Size ranging from around 10 nm up 700 nm, with a peak around 150 nm
nanoparticles in food chain
agriculture
food processing
food packaging
supplement
nanoparticles in agriculture
nano capsules to delivers fertilisers and insecticides
delivery of growth hormones
nanochips to identify preservation and tracking
nanoparticles in food processing
nano-encapsulated flavour enhancers
nanotubes and nanoparticles as gelation and viscosifying agent
nanoemulsions and nanoparticles for even distribution of nutrients
nano particles in food packaging
antibodies attached to fluorescent nanoparticles to detect chemicals and foodborne pathogens
biodegradable nanosensors for temperature, moisture and time monitoring
nanoclays and nano foils to form a barrier to prevent food spoilage and oxygen absoprtion
nano particles in supplements
nanosize powder increase absorption of nutrients
cellulose nano crystals composites as drug carriers
nano chelates to deliver nutrients more efficiently without influencing flavour and colour
titanium dioxide in food
high conc - powdered mini donuts, mentos freshmint gum
mid conc - whipped cream m&m peanuts
low conc - mentos and coffee
size of nano particles depending on where it is in the nasal cavity and lungs
nasal passage: 11-7 PM Pharynx: 7-4.7 PM Trachea: 4.7-3.3PM Primary bronchi: 4.7 - 3.3PM Bronchi branches: 2.1-1.1PM Bronchioli: 1.1 - 0.65 PM Alveoli: 0.65-0.43 PM
Components of nasopharyngeal region
nasal airway
pharynx
larynx
Components of tracheobronchiol region
Trachea Bronchi Lymph nodes Non respiratory bronchioles Pulmonary arteries and veins
Components of Alveolar
Alveolar ducts
Alveolar sacs
Alveolar capillary bed
2 main clearance pathways
muscociliary escalator (tracheobronchial) phagocytosis by macrophages (alveoli)
process of muscociliary escalator clearance pathway in central lung
- drug must cross pulmonary epithelium
- they can reach underlying tissue or circulatory system
- mucociliary clearance in the airways
process of phagocytosis by macrophages in peripheral lung
- drug must cross pulmonary epithelium
- they can reach underlying tissue or circulatory system
- macrophage clearance
what does translocation of nanoparticles across major protective barriers in the body depend on?
depends on size and surface properties of particles
describe the nanoparticles that can translocate rapidly and where do they translocate to?
nanoparticles with hydrodynamic diameter less than 34nm and noncationic surface charge translocate rapidly from lung to mediastinal lymph nodes.
how fast can nanoparticles of hydrodynamic diameter greater than HD < 6nm translocate
traffic rapidly from lungs to lymph nodes and the bloodstream, and then be subsequently cleared by kidneys and secreted with urine
where can particles less than 34nm in size with a non positive charge on its surface cross
protective barriers e.g. lung endothelium and travel to many parts of the body in circulation
name an example of nanoparticles and where it can transfer and how does it affect the body
tobacco smoke reduced the levels of the enzyme
monoamine oxidase (MAO)
by 33%-43%. MAO indirectly controls blood pressure
nanoparticles that are greater than 750nm are absorbed by cells or cell organelles …
phagocytosis
nanoparticles that are less than or equal to 2000nm are absorbed by cells or cell organelles by …
pinocytosis
nanoparticles that are less than or equal to 100nm are absorbed by cells or cell organelles by
endocytosis
