[Secondary structure of insulin encapsulated within liposomes].
OBJECTIVE
To determine the secondary structure of insulin encapsulated within liposomes.


METHODS
The secondary structure of insulin, mixture of insulin with liposomes (I) and insulin liposomes (II) were determined by Fourier transform infrared (FTIR) spectroscopy.


RESULTS
The figures of secondary structure of insulin, sample I and II were similar. The results showed that the amount of alpha-helix and beta-sheet of insulin, sample I and II had little difference, from 36.09% (insulin) to 31.68% (sample I) and 31.45% (sample II), and from 47.83% (insulin) to 53.29% (I) and 51.36% (II), respectively. The results showed that the insulin of sample I and II did not insert in liposomes membrane, only adsorbed or extendedon the surface of the liposomes.


CONCLUSIONS
The secondary structure of insulin encapsulated within liposomes has not been destroyed and still remain the original state.
Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China.
Xuan
X
Zhang
Li-xin
LX
Huang
Song-qing
SQ
Nie
Xian-rong
XR
Qi
Qiang
Q
Zhang
D004337:Drug Carriers; D016503:Drug Delivery Systems; D007328:Insulin / Q000008:administration & dosage / Q000737:chemistry*; D008081:Liposomes; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared
D004337:Drug Carriers; D007328:Insulin; D008081:Liposomes