Phospholipids are insoluble in water. Depending on the lipid composition, you may be able to prepare a suspension by homogenizing the lipid in buffer, medium or water. Sonicating the suspension in water may produce a clear suspension of liposomes that can be added to the growth medium. The sonication should be done at a temperature above the transition temperature of the lipids using a bath sonicator, with the lipids in a sealed tube flushed with inert gas to prevent oxidation. (Probe sonicators shed metal particles that you don't want in your sample.)

To get a fairly homogeneous size population of unilamellar liposomes, if that is desired, the liposome suspension can be extruded through polycarbonate membranes having a specific pore size at a temperature above the transition temperature of the lipid. This requires special equipment.

You could also dissolve the phospholipids in a water-miscible solvent such as DMSO. As soon as the solution is added to medium, the phospholipids will precipitate, however, and there is a limit to how much organic solvent the cells will tolerate. Phospholipids will also dissolve in detergents, but these may be incompatible with the cells. The utility of these approaches depends on the concentration of phospholipids you are trying to reach in the growth medium.

Dear Razan Alomosh

You can make emulsions with phospholipid solution for physiological delivery to treat cells in cell culture.

Good luck!