Facilities

There are avalable in our lab the following equipments for everyday use:

• Differential scanning calorimetry (DSC), model VP-DSC (Microcal Inc. Northmpton, MA, USA), extremly used to investigate the thermal behavior of D_nDAB vesicles and their interactions with several additives.

• UV-vis spectrophotometer Cary, model 300 Bio, also highly used to investigate mixtures of D_nDAB vesicles with additives, at varying temperatures (FAPESP).

• KSV Nima Langmuir and Langmuir-Bodgett troughs of study of lipid monolayers. The interactions of cationic lipid nonolayers with co-slutes in the subphase are compared to the interactions of cationic vesicles of the same lipids and co-solutes (FAPESP).

Zeta Potential Analyser (ZetaPlus). This instrument allows us to measure zeta potentials of colloidal particles.

Static and dynamic light scattering techniques are (Brookhaven Instruments) are powerful tecniques to investigate colloidal systems and associated colloids (supported by FAPESP).

Based on DSC and SAXS data, we constucted the following "phase diagram" for DODAB/water system, up to 120 mM DODAB, at 1 ^oC, where ULV and MLS account for unilamellar vesicles and multilamellar structures, respectively. Typical heating and cooling DSC thermograms were included for samples from each "phase" area.

The Figure below depicts representative DSC heating thermograms for DODAB vesicles at 5 mM, showin how the initial scanning temperature affects the subgel-to-gel at T_p ≈ 36 ^oC and T_m ≈ 45 ^oC and the gel-to-liquid crystalline at T_m ≈ 45 ^oC.

Recently we got support from the brazilian Agency FAPESP to equip our lab with a static and dynamic light scattering and a Langmuir trough. Soon these equipments will be available in our lab.