Lipid PEG

BOC Sciences offers a variety of PEG-Lipid derivatives with different molecular weights and different functional groups, including Cholesterol-PEG, DSPE-PEG, mPEG Ceramides, mPEG Glycerides, mPEG Phospholipids, mPEG Sterols, etc. Commonly used PEG molecular weights range from 600-12,000, and the most commonly used molecular weights are 2,000 to 5,000. Conjugated lipid structures include saturated/unsaturated phosphatidylethanolamine (PE) as well as cholesterol and short-chain phospholipids (C8), medium- and long-chain (C14), and long-chain (C20) fatty amides.

What are PEG Lipids?

Lipid PEG, also known as polyethylene glycolated lipids, are PEG derivatives containing lipid molecules such as DSPE that have been used for bioadhesive and lipid nanoparticle (LNP) drug delivery to improve the cycle time of liposomal encapsulated drugs. Lipid molecules are low toxic and easy to prepare, and can be used as carriers not only for water-soluble drugs but also for lipid-soluble drugs. Therefore, PEG lipids can be used to improve drug stability, multiple routes of drug delivery, and enable targeted drug delivery.

Fig. 1. PEG-modified liposomes conjugated with MLP.

Lipid PEG Derivatives

In 1984, phospholipids were successfully coupled to PEG via amide bond coupling of carboxyl-PEG to purified PE. Since then, the connection between PEG and PE has been known by researchers around the world, and has further covered a variety of esters and carbamate derivatives. The anticancer drug PEG-liposomal doxorubicin (Doxil) has been produced and marketed. A variety of PEG-liposome drugs have also entered clinical phase II/III trials, which indicates that the PEG-liposome drug preparation technology has matured. PEG modification solves the shortcomings of ordinary liposomes, allows liposomes to remain in the blood for a longer period of time, and increases the passive targeting function of drugs. Moreover, PEG is cheap and easy to obtain, can be produced on a large scale, has easy molecular weight control, and has good physical and chemical properties.

DSPE-PEG

DSPE-PEG (DSPE-PEG-Biotin, DSPE-PEG-MAL, DSPE-PEG-NH2, DSPE-PEG-NHS) is a phospholipid-polymer conjugate widely used for drug delivery. It is a biocompatible, biodegradable and amphiphilic material that can be functionally modified with various biological macromolecules to achieve specific functions. With the emergence of interest in nanocarriers for drug delivery and imaging, DSPE-PEG has become a very useful material in the formulation of these nanocarriers to extend blood circulation time, improve stability, and increase encapsulation efficiency.

Cholesterol-PEG

Cholesterol-PEG (Cholesterol-PEG-Amine, Cholesterol-PEG-DBCO, Cholesterol-PEG-MAL, Cholesterol-PEG-NHS) is a polymer composed of cholesterol and PEG conjugated. Cholesterol-PEG has unique chemical properties and structure and is therefore widely used in drug development to enhance the pharmacokinetics and pharmacodynamics of drugs. Cholesterol-PEG is amphipathic because it has both hydrophilic PEG and hydrophobic cholesterol. This property enables cholesterol-PEG to interact with both aqueous and lipid environments, making it an ideal carrier for hydrophobic or hydrophilic drugs. In addition, cholesterol-PEG can also self-assemble into micelles, which are spherical structures with a hydrophobic core and a hydrophilic shell. This property enables it to encapsulate hydrophobic drugs and protect them from degradation in the body.

Functionalized PEG Lipids

PEG is the most widely used polymer in liposome formulations. The individual hydroxyl groups of lipid PEG can be coupled to small molecule drugs, antibodies and click chemistry groups to formulate liposomes with different functions. Lipid PEG can further contribute to particle stability by reducing particle aggregation, and PEG optimization can prolong the circulation time of nanoparticles by reducing renal and mononuclear phagocyte system-mediated clearance. Finally, lipid PEGs can also be used to bind specific ligands to particles for targeted delivery.

Fig. 2. Functional peptide-PEG-lipids (Biomaterials. 2020, 253: 120113).

Lipid PEG for Drug Delivery

In PEG lipids, the PEG chain is typically attached to the head group of a lipid molecule, such as a phospholipid or glycolipid. The obtained PEG lipids can be used to form various drug delivery systems, such as liposomes, micelles and lipid nanoparticles. PEG-terminated liposomes as passive targeted drug delivery carriers for the treatment of cancer and infectious diseases have attracted wide attention. They are superior to other carriers in increasing the systemic circulation time of drugs, delivering active molecules to the site of action, and protecting healthy tissues from toxic damage. In the preparation process, the key step in the development of long-circulating liposomes is to add a synthetic polymer PEG, such as PEG-DSPE, to the liposome composition.

BOC Sciences has developed a variety of PEG lipid products, including functionalized Cholesterol-PEG, DSPE-PEG, and mPEG lipid small molecules, to meet the various needs and specifications of researchers and manufacturers. Whether you need to label, purify, or conjugate substances such as drugs, PEG lipids can provide reliable and efficient solutions to enhance your research and development. Contact us to learn more about our products and services.

Reference

1. Yoshihara A. et al. Promotion of cell membrane fusion by cell-cell attachment through cell surface modification with functional peptide-PEG-lipids. Biomaterials. 2020, 253: 120113.