[Interactions of insulin with dipalmitoylphosphatidylcholine liposomes].
OBJECTIVE
To study the interactions of insulin with dipalmitoylphosphatidylcholine liposomes.


METHODS
The liposomes were prepared by reverse-phase evaporation vesicle method. The entrapped efficiency, size and distribution of the liposomes were determined, and the influences of insulin on entrapped efficiency, size and distribution of the liposomes were investigated. The influences of liposomes on the fluorescence emission spectra of insulin and the calcein leakage from the liposomes entrapped calcein induced by insulin were measured.


RESULTS
Insulin has little influence on the size and distribution of the liposomes while the sizes of the liposomes were about 170-190 nm. The insertion of tyrosine of insulin into dipalmitoylphosphatidylcholine liposomes membrane was not deep. The insulin disturbed the liposomes membrane, induced the calcein leakage from the calcein-loaded liposomes.


CONCLUSIONS
Amphiphilic, example insulin, may disturb the intact membrane of liposome through the interaction either hydrophobic or hydrophilic. The attention should be paid to the entrapment process of peptides into liposomes.
Qi
X R
XR
Peking University, School of Pharmaceutical Science, Beijing 100083, China.
Maitani
Y
Y
Hou
X P
XP
Zhang
Q
Q
Wei
S L
SL
Nagai
T
T
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers; D007328:Insulin / Q000008:administration & dosage* / Q000378:metabolism; D008081:Liposomes / Q000008:administration & dosage / Q000737:chemistry
D004337:Drug Carriers; D007328:Insulin; D008081:Liposomes; D015060:1,2-Dipalmitoylphosphatidylcholine