Current Synthetic and Systems Biology
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Liposomes: Structure, Types and Applications in Drug Delivery

Abhisaya Adwar^{* *}Correspondence: Abhisaya Adwar, Department of Synthetic Biology, Amity University, Noida, India, Email:

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Description

Liposomes are nanosized vesicles composed of phospholipids, widely recognized for their unique structure and remarkable applications in the field of drug delivery. These spherical, bilayered lipid structures have gained significant attention due to their ability to encapsulate various therapeutic agents, such as drugs, proteins, and genetic material. This article discusses about liposomes, their formation, properties, and diverse applications in targeted drug delivery systems.

Structure and formation

Liposomes consist of an aqueous core surrounded by one or more phospholipid bilayers. These phospholipids arrange themselves spontaneously in an aqueous medium, forming closed vesicles. The bilayer structure enables liposomes to encapsulate both hydrophilic and hydrophobic substances, making them versatile carriers for a wide range of therapeutic compounds. The size of liposomes can vary from tens to hundreds of nanometres, depending on the desired application.

Types of liposomes

Liposomes can be categorized into several types based on their composition and structure. Conventional liposomes are composed of phospholipids, while various modifications have led to the development of different types, including stealth liposomes, cationic liposomes, and pH-sensitive liposomes. Stealth liposomes, coated with Poly Ethylene Glycol (PEG), are designed to evade the immune system, prolonging their circulation time in the bloodstream. Cationic liposomes possess positive charges and are effective in delivering genetic material. pH-sensitive liposomes respond to changes in pH, facilitating targeted drug release in specific tissues or cellular compartments.

Applications in drug delivery

Liposomes have revolutionized the field of drug delivery by overcoming several limitations associated with conventional methods. They offer numerous advantages, such as improved drug solubility, prolonged drug circulation, enhanced stability, reduced toxicity, and targeted delivery to specific tissues or cells.

Targeted drug delivery is one of the most promising applications of liposomes. By modifying the surface of liposomes with ligands or antibodies specific to a particular cell type or tissue, they can selectively deliver drugs to the desired site while minimizing offtarget effects. This approach has proven highly beneficial in the treatment of cancer, where liposomes can accumulate in tumour tissues and release anticancer drugs selectively.

Liposomes also play a vital role in the delivery of fragile biomolecules, such as proteins and genetic material.

Encapsulating these compounds within liposomes protects them from degradation and improves their stability, ensuring their therapeutic efficacy.

Furthermore, liposomes have found applications in the treatment of various diseases, including infectious diseases, cardiovascular disorders, and neurological disorders. They can encapsulate antibiotics to improve their bioavailability and target specific sites of infection. In cardiovascular diseases, liposomes loaded with vasodilators can enhance drug delivery to the heart, offering potential therapeutic benefits. Liposomes can also cross the blood-brain barrier, enabling the targeted delivery of drugs to the central nervous system, addressing neurological disorders.

Liposomes have emerged as versatile Nano carriers that have revolutionized the field of drug delivery. Their unique structure, ability to encapsulate various therapeutic agents, and versatility in surface modification have made them an attractive platform for targeted drug delivery systems. With ongoing research and advancements, liposomes hold immense potential in improving the efficacy, safety, and specificity of drug therapies. As scientists continue to explore new techniques for liposome formulation and functionalization, further breakthroughs can be expected that will contribute to the advancement of personalized medicine and improved treatment options for various diseases.