RESUMO
<p><b>AIM</b>To determine the secondary structure of insulin encapsulated within liposomes.</p><p><b>METHODS</b>The secondary structure of insulin, mixture of insulin with liposomes (I) and insulin liposomes (II) were determined by Fourier transform infrared (FTIR) spectroscopy.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>The secondary structure of insulin encapsulated within liposomes has not been destroyed and still remain the original state.</p>