Nanotoxicology Flashcards
why is nanoparticle size important for nanotoxicology?
diameter dependent excretion
e.g. zwitterionic cysteine coated quantum dots
e.g. PMAM-gold NPs accumulate in the blood = increase size
- larger size found in liver and spleen/ smaller size excreted in the urine
why is nanoparticle surface charge important for nanotoxicology?
increase conc of [DOPC:DOTAP:CHOL] in DOPC:DOTAP:CHOL:PEG liposomes
DOPC:DOTAP:CHOL = positive charge
charged liposomes = cleared quickly
what does DOPC:DOTAP:CHOL do to liposomes?
give it a/increase positive charge = aggregate with proteins in the blood = lung accumulation
where do DOPC:DOTAP:CHOL liposomes deliver drugs? why?
lung
due to protein aggregation due to their positive charge
how does PEG improve nanotoxicology?
mask surface charge = stop lung accumulation and fast excretion
= increasing the liposomes half life
why is nanoparticle shape important for nanotoxicology?
important for phagocytosis
pointed end of elliptical disc = fast phagocytosis (few minutes)
contact with flat region = slow phagocytosis (over 12hours)
why is it hard to use traditional toxicology assays for NPs?
e.g. CNTs - π–π stacking between CNT and reagents in the toxicology assays like MTT and LDH assay
π–π stacking with polycyclic nature/rings = blocks absorbance and fluorescent readings
what are traditional toxicology assays?
MTT - mitochondrial succinate dehydrogenase
LDH- lactate dehydrogenase
what reagents are used in traditional toxicology assays?
polycyclic nature/rings
how does LDH- lactate dehydrogenase work?
LDH releases when cells have defects in the membrane
= LDH detection
= toxicology reported
what is the toxic effect of NPs we are worried about?
biological side effects
environmental/workplace exposure of CNTs - lung and skin exposure
name NP affects
- NP inhalation
- brain - parkinson’s/alzheimer’s
- lung - asthma/bronchitis/emphysema/cancer
- circulatory - artherosclerosis/ vasoconstriction/ thrombus/ high bP
- heart - arrhythmia/ heart disease/ death
- lymphatic system - kaposi’s sarcoma
- skin - auto-immune diseases - NP ingestion
- GI - crohn’s disease/colon cancer
- orthopedic implants wear debris - auto-immune diseases/dermatitis/ urticaria/vasculitis
what type of NPs are less toxic?
chemically functionalised CNTs
what type of chemical functionalisations can you make to MWNTs?
- addition of alkyl chain - hydrophobic
- addition of ammonium chain - hydrophobic, increase dispersibility
how are inflammatory reactions notices with CNTs?
granuloma formation
- mass of immune cells that forms when the immune system attempts to eliminate substances
