If you mean liposome, it's a tiny bubble like pouch. It's outerlayer that holds it together is made out of the same thing that cell membranes are made up of (phosopholipids), however liposomes are filled with drugs. They can be used to deliver vaccinations, enzymes, drugs for things like cancer treatment..etc
They are most useful for immune system diseases that affect defense cells called phagocytes, which are large cells that gobble up things that are foreign and don't belong in the body because they don't recognize them so they go around eating them up (it's called phagocytosis) which helps deliver the drug more effectively.