I am preparing liposomes using Lipoid S-75, S-100, and E-80, but when I am hydrating these lipid films at 60 oC using PBS 7.4, these lipids start settling down after some time. I am not getting why is this happening. So wanted to know the ideal hydration temperature or transition temperatures of these lipids.
They are supposed to be 75 % of PCs with unsaturations. The normal melting temperature of DPPC is 42 °C white for DSPC is 55 °C. The addition of insaturations, like for a 16:1 PC already brings the melting temperature at -36 °C, which becomes -17 °C for a 18:1 PC.
Good luck
The first letter refers to the source of the phospholipid. S = soy, E = egg; the second number refers to the % of phosphatidylcholine in the powder. What is missing is the third number that is often given, which refers to thew iodine number. For example, S-100-3 would refer to fully hydrogenated egg phosphatidylcholine. Given that the fatty acid composition is heavily weighted by C18 fatty acids, this material would have a Tm of ca., 55 C. S-100-30 or S-100-60, have increasing amounts of unsaturation, driving the transition temperatures below 0 C. Similar situation with the egg, although the fatty acid composition is much more complicated... Contact Lipoid, and they will give you a full list of the Tm values...
- Badges
- Science method