Controllo dell Morfologie Macroscopiche di Fibre Peptidiche attraverso essiccazione all'interno di Superifici Microstrutturate

Lanreotide is an octapeptide that forms self-assembled nanotubes after being mixed in solution with surfactants. During this study, hexadecyltrimethylammonium bromide (CTAB) and commercial Tween 20 surfactants were used to induce nanotube fiber formation by drying liquid droplets of peptide-surfactant solution in between glass substrates and to control their morphological features with polydimethylsiloxane (PDMS) microtextured stamps. The morphology of the peptide-surfactant structures was studied by polarized light microscopy (PLM). PLM is a technique that reveals structural information of birefringent materials by giving high resolution-contrast images. The images obtained by PLM and optical microscopy for the glass supports revealed peptide fiber formation upon drying, mainly enhanced at the liquid droplet interface. As an important remark, CTAB formed crystalline and dendritic structures after drying in regions where lanreotide was absent; therefore Tween 20 was studied afterwards. Furthermore, PDMS stamps prepared by soft lithography were used to dry the peptide solution and subsequently, the fibers formed structures known as walls along the pillars upon drying. Additionally, small-angle x-ray scattering (SAXS) was carried out at the high brilliance SWING beamline of the SOLEIL synchrotron light source to study the structure of the peptide fibers and to obtain information of the radius of the nanotubes.