Liposomes Flashcards
What is a liposome?
Vesicular structure made of a bilayer around a aqueous core
Considered as a liquid crystal
Functions of liposomes
Carries strongly hydrophobic drugs within bilayer
Carries strongly hydrophilic drugs in aqueous core
Carries intermediate logP drugs somewhere between
Rigidity and permeability of lipsomes is determined by…
Alkyl chain length and unsaturation
Cholesterol for rigidity
Why use liposomes as carriers?
Biocompatible and degradable
Biologically inert and low toxicity
Conventional lipsomes are…
Neutral -vely charged
Passively targets MPS cells in liver spleen
They are rapidly taken up by phagocytes and taken from blood circulation
eg. carries amphotericin B, doxorubicin and hep A vaccines
Sterically stabilised liposomes are…
Covered in a hydrophilic coating allowing for a prolonged circulation time
The hydrophilic PEG group creates barrier against interaction with cellular components
Can cause transient reactions in a subset of patients
Immunoliposomes are…
sterically stabilised or convetional
They have specific antibodies on their surface and are targeted at cancer
The steric PEG chain can interfere with antigen binding
Cationic liposomes are…
+vly charged and carry genetic material. Thischarge interacts with -ve DNA condensing it into a more compact structure
Can activate complement and cause adverse effects
