Browsing by Author "Vartiainen, Ville"

Polypeptide-surfactant complexes are macromolecules capable of taking similar secondary structures to polypeptides. In this thesis it was shown that it is possible to control the secondary structure of poly(L-lysine)-dodecylbenzenesulfonic acid complexes in nanoparticles by varying solvent and aerosol reactor temperature. Using chloroform as the solvent promoted α-helix while 1-propanol promoted β-sheet secondary structure. Dimethylformamide (DMF) seemed to induce random coil. When chloroform was used in the aerosol process, transformation from α-helix to β-sheet occured between 80°C and 100°C. Secondary structure was measured using FT-IR. Above and below the transition temperature the secondary structure was relatively independed of the reactor temperature. Similar transition was also observed with 1-propanol and DMF, but transition states were also seen. Addition of tertiary molecules to the nanoparticles prevented formation of the β-sheet in 100°C and 1-propanol. Lamellar self-assembly was observed with TEM in all the particles, while it was expected only in particles with complexes in β-sheet secondary structure.