Liposomes can be conjugated with different molecules to achieve specific targeting and enhance drug delivery. As a CRO focus on bioconjugation, BOC Sciences provides liposome conjugation service to meet our customers' demand and accelerate their drug development.
Liposomes are artificial vesicles that mimic the structure of natural cell membranes. Liposomes are self-assembled, hollow structures consisting of one or more concentric lipid bilayers, which are often referred to as artificial cells. These small, spherical structures have an aqueous core encapsulated within lipid bilayers. The versatility of liposomes lies in their ability to encapsulate both hydrophilic and hydrophobic drugs, protecting them from degradation and increasing their solubility. Liposomes can range in size from tens to hundreds of nanometers, making them ideal vehicles for a wide range of therapeutic agents. By modifying the lipid composition and size, the release rate and stability of the encapsulated drug can be controlled.
Certain molecules can bind to liposomes and become affixed to the liposome's surface. These substances, referred to as ligands, can be antibodies, aptamers, peptides, small compounds, or other targeting moieties that recognize and bind to certain receptors on target cells to facilitate tailored drug delivery, boosting therapeutic efficacy while decreasing off-target consequences. Liposomes can also be conjugated with carbohydrates. Carbohydrates, particularly glycolipids or glycoproteins, can be used to target liposomes to cells expressing lectins, which are sugar-binding proteins.
Fig. 1 Liposomes Conjugated with carbohydrates
In addition to therapeutic agents, imaging agents, such as fluorescent dyes or radioactive labels, can be incorporated into liposomes, enabling non-invasive monitoring of drug distribution and accumulation in the body. Liposomes provide a protective environment for these agents, shielding them from degradation and enhancing their stability.
Fig. 2 Liposomes Conjugated with therapeutic / imaging agents
The reactive functional groups on the liposome surface react with reactive groups on the ligand, forming stable chemical bonds. The conjugation chemistry can be achieved through the use of coupling agents such as carbodiimides or maleimides. Covalent conjugation ensures a durable linkage between the liposome and the ligand, preventing their dissociation under physiological conditions. This strategy is particularly useful when a strong and stable attachment is required.
These approaches rely on the use of electrostatic interaction, hydrophobic interaction, or host-guest interaction to attach the ligand to the liposome surface. Non-covalent conjugation strategies offer advantages including simplicity, reversibility, and the ability to release the ligand under specific conditions, providing control over drug release kinetics.
In order to improve the accessibility of the conjugated ligands and lessen steric hindrance, liposomes might be modified using spacer molecules. To generate separation between the liposome surface and the ligand, spacer molecules act as a bridge. This makes it possible for the ligand and its target receptors to interact more effectively, improving the effectiveness of targeted medication delivery. Short peptides, polymers, and linkers are all examples of spacer molecules.
Our liposome conjugated molecules also include Oligonuleotide, Carbohydrate, Enzyme, Protein, Drug, Biotin, etc. If you would like more information, please contact us.
