Liposomal Drug Administrations

Question 1

What is the difference between Daunorubicin, Daunoxome and Doxil.

Answer 1

Anticancer drug,
liposomal form of drug.
2nd generation stealth form of drug.

Question 2

what are the main benefits of lipid mediated drug delivery?

Answer 2

Aq environment inside & out.
Delivery mechanism (protect body from drug & vice versa). 
Circulation time. 
Controlled release
Specificity.

Question 3

What experiments have been done to try and target lipoplexes?

Answer 3

adding targeting pepetide - K16-A-G-A-C-R-R-E-T-A-W-A-C
K domain binds & condense plasmid DNA

cyclic domain binds alpha and beta integrin allowing internalisation via receptor mediated endocytosis.

Question 4

What is problematic about systemic lipoplex administration?

Answer 4

PEG coating reduces uptake by MPS but severely reduces transfection.
Targeting ligands such as peptides & antibodies attached to restore transfection
Folate - 10,000 fold reduction compared to 10 fold.

Question 5

What is one notable benefit of 2nd generation liposomes?

Answer 5

MDR has been acquired by many cancers due to; increased drug metabolism, drug transporter & efflux protein overxpression.

Male mice with colon cancer or doxorubicin resistant sub clone - doxil had anti-tumour effects in both cases.

Question 6

What is passive targeting?

Answer 6

Complexes diffuse and accumulate at sites with excessive leaky microvasculature.

VEGF imbalance –> increased vascular permeability

Enhanced permeation of drugs.

Question 7

What do opsonins do?

Answer 7

Bind foreign material and enhance phagocytosis (e.g. IgA)