Phospholipid liposomes are used as targeted drug delivery systems. Hydrophilic drugs can be carried as solution inside the SUVs or MLVs and hydrophobic drugs can be incorporated into lipid bilayer of these liposomes. If injected into circulation of human/animal body, MLVs are preferentially taken up phagocytic cells, and thus drugs can be targeted to these cells. For general or overall delivery, SUVs may be used. For topical applications on skin, specialized lipids like phospholipids and  sphingolipids may be used to make drug-free liposomes as moisturizers, and with drugs such as  for anti-ultraviolet radiation applications.
In biomedical research, unilamellar liposomes are extremely useful to study biological systems and mimicking cell functions. As a living cell is very complicated to study, unilamellar liposomes provide a simple tool to study membrane interaction events such as membrane fusion, protein localization in the plasma membrane, study ion channels, etc.