Nanotoxicity

Question 1

Nanoparticles

Answer 1

Structures with at least 1-D in the range of 1-100nM
On the nanoscale
In things like golf ball, tennis racket, nano-silver antibacterial socks, clear sunscreen etc.
Decoy receptor using nanoparticles
-A carefully constructed spherical nanoparticle coated in sialic acid lures influenza A virus to its doom.

Question 2

3 Key properties and Diversity

Answer 2

Size, shape, and structure
Surface charge and reality
Dose metric-particle number, mass or relative SA
Nano have higher SA=> increase contact w/ surroundings
Size change with colour

Question 3

Chemistry and Geometry

Answer 3

Range in composition, geometry and complexity
Vast number of potential NP from all elements
Current key NP: ZnO, TiO2, fullerenes, CNT, nanosilver, quantum dots, polymers

Aggregation: particle size, hydrodynamic diameter, zeta potential

• NP strong tendency to form aggregates
• consequence of hydrophobic forces drive agglomeration
• physiological fluids can screen particle surface charge

Question 4

Surface reactivity

Answer 4

High surface area=inc reactivity
Surface charge
Hydrophobicity and partitioning into lipid membrane
Dissolution + release metal ions = redox activity leading to generation of ROS

Question 5

Biological coating

Answer 5

PROTEIN CORONA: the protein adsorption layer that form on surface of colloidal nanoparticles play important role in their interaction w/ living matter
-Hemolytic without corona,

Question 6

DoseMetric

Answer 6

Unrealistic high NP levels in experiments, mg/kg, nmol/L
Physicochemical properties
Surface area, mass or number of particles?
For toxicity: NP more toxic w/ less mass, but less toxic with higher numbers particles
SA show no diff in toxic response: may be better indicator

Question 7

Toxicokinetic(ADME)

Answer 7

Absorption: GIT, dermal, lungs, injection, variable transport across epithelia barriers

Distribution: can reach systemic, organ and tissue, interact w/ blood component, lymph vessels and entrapment in lymph nodes, adhesion to capp walls, protein corona
Influenced by 3 factors***
Particle size
Surface modification
Portal of entry

Metabolism: little known regarding metabolism, unlikely inert nanoparticles. Evidence func groups added maybe metabolized

Excretion excreted by various routes, influenced by size, shape, hydrophobicity and charge.
Renal filtration, hepatic export

Question 8

Toxicity

Answer 8

Very little is known concerning the toxicity of NPs
Toxicity is influenced by shape, size, charge, formulation
Vast amount of different NPs