Tocopherol-phospholipid liposomes: maximum content and stability to serum proteins

Area of Science:

• Biochemistry
• Materials Science
• Pharmacology

Background:

• Liposomes are widely used drug delivery systems.
• Alpha-tocopherol (vitamin E) is a crucial antioxidant with therapeutic potential.
• Understanding liposome composition and stability is vital for effective delivery.

Purpose of the Study:

• To determine the maximum tocopherol incorporation in egg phosphatidylcholine liposomes.
• To evaluate the stability of these liposomes when exposed to serum proteins.

Main Methods:

• Liposomes were prepared using a French pressure cell.
• Tocopherol content was quantified using molar percentages.
• Liposome stability was assessed by resistance to protein-induced disruption.

Main Results:

• Egg phosphatidylcholine liposomes can incorporate a maximum of 33 mol% tocopherol.
• Increased tocopherol content enlarged liposomes and reduced their permeability.
• Tocopherol significantly enhanced liposome resistance to protein-induced disruption, surpassing cholesterol's effect.

Conclusions:

• Liposomes can be effectively loaded with alpha-tocopherol up to 33 mol%.
• Tocopherol incorporation improves liposome stability and resistance to serum proteins.
• These findings support the use of tocopherol-loaded liposomes for in vitro and in vivo vitamin delivery.