Atomic Force Microscopy Study on the Stiffness of
Nanosized Liposomes Containing Charged Lipids
Yuki Takechi-Haraya
Yukihiro Goda
Kumiko Sakai-Kato
10.1021/acs.langmuir.8b01121.s001
https://acs.figshare.com/articles/journal_contribution/Atomic_Force_Microscopy_Study_on_the_Stiffness_of_Nanosized_Liposomes_Containing_Charged_Lipids/6591470
It has recently been
recognized that the mechanical properties
of lipid nanoparticles play an important role during in vitro and
in vivo behaviors such as cellular uptake, blood circulation, and
biodistribution. However, there have been no quantitative investigations
of the effect of commonly used charged lipids on the stiffness of
nanosized liposomes. In this study, by means of atomic force microscopy
(AFM), we quantified the stiffness of nanosized liposomes composed
of neutrally charged lipids combined with positively or negatively
charged lipids while simultaneously imaging the liposomes in aqueous
medium. Our results showed that charged lipids, whether negatively
or positively charged, have the effect of reducing the stiffness of
nanosized liposomes, independently of the saturation degree of the
lipid acyl chains; the measured stiffness values of liposomes containing
charged lipids are 30–60% lower than those of their neutral
counterpart liposomes. In addition, we demonstrated that the Laurdan
generalized polarization values, which are related to the hydration
degree of the liposomal membrane interface and often used as a qualitative
indicator of liposomal membrane stiffness, do not directly correlate
with the physical stiffness values of the liposomes prepared in this
study. However, our results indicate that direct quantitative AFM
measurement is a valuable method to gain molecular-scale information
about how the hydration degree of liposomal interfaces reflects (or
does not reflect) liposome stiffness as a macroscopic property. Our
AFM method will contribute to the quantitative characterization of
the nano–bio interaction of nanoparticles and to the optimization
of the lipid composition of liposomes for clinical use.
2018-06-05 00:00:00
lipid acyl chains
gain molecular-scale information
AFM
liposomal membrane stiffness
nanosized liposomes
Nanosized Liposomes Containing Charged Lipids
stiffness values
hydration degree
Atomic Force Microscopy Study
liposomal membrane interface