| LNP Composition and Parameters |
| lipid composition |
•cholesterol
as a helper lipid suppresses protein binding
and improves circulation time; it is also essential to particle stability113,166
|
| •high cholesterol percentage in
the bilayer membrane
(≥70%) causes higher complement activation167
|
| •phosphatidylcholines such
as DSPC as helper lipids
improve endocytosis of LNPs; substituting DSPC with the unsaturated
DOPC and SOPC causes enhanced particle uptake and intracellular delivery113,164,168
|
| size and surface charge |
•a rise
in the PEG–lipid molar part from 1% to
5% correlates with significantly smaller LNPs163,164
|
| •increased vesicle size and polydispersity
of large
multilamellar liposomes enhance pulmonary hypertensive response, while
small unilamellar, monodisperse liposomes had no significant vasoactivity160
|
| •anionic PEG–lipids
undergo a drop in particle
size with increasing PEG size and molar ratios in the LNPs169
|
| •PEGylated
carriers comprising negatively charged phospholipids
stimulate complement activation stronger than neutral vesicles127
|
| •the effect
of particle size on LNP immunogenicity is
controversial and requires further investigations15
|
