posted on 2021-08-03, 15:11authored byYuya Sato, Kenta Asawa, Tianwei Huang, Makoto Noiri, Naoko Nakamura, Kristina N. Ekdahl, Bo Nilsson, Kazuhiko Ishihara, Yuji Teramura
The use of amphiphilic molecules
such as poly(ethylene glycol)-conjugated
phospholipid (PEG-lipid) enables incorporation into liposome surfaces
by exogenous addition as a result of the self-assembly with lipids.
This technique can be applicable for manipulation of both liposomes
and cells. In this study, we aimed to characterize Tat peptide (YGRKKRRQRRR)-conjugated
PEG-lipids when used to exogenously surface modify liposomes (size:
ca. 100 nm). We earlier reported that cells, which were surface modified
with Tat peptides conjugated to PEG-lipids could attach spontaneously
to material surfaces without any chemical modification. Here, we synthesized
different types of Tat-PEG-lipids by combining PEG of different molecular
weights (5 and 40 kDa) with different lipids with three acyl chains
(myristoyl, palmitoyl, and stearoyl, respectively) and then studied
the spontaneous adsorption of modified liposomes onto a substrate
surface induced by the different Tat-PEG-lipids. The amount of adsorbed
liposomes strongly depended on the number of incorporated Tat-PEG-lipid
moieties: a decrease in both the PEG and the acyl chain lengths led
to adsorption of higher amounts of liposomes. Furthermore, when a
collagenase-cleavable amino acid sequence was inserted between the
Tat sequence and the PEG segment, adsorbed liposomes could be harvested
from the substrate by collagenase treatment with no difference in
desorption efficiency between the different Tat-PEG-lipids. Thus,
Tat-PEG-lipid can be a suitable tool for the manipulation of liposomes
and cells.