Liposomes, composed of a phospholipid bilayer encapsulating an aqueous core, are spherical vesicles that self-assemble. These vesicles come from phospholipids with specific fatty-acid chains. Liposomes have a unilamellar structure with a single layer of phospholipids or a multi-lamellar structure with concentric shells of phospholipids. Therefore the hydrophilic molecules within the core combine with the hydrophobic molecules in the bilayers. The lipid bi-layered structure of liposomes is similar to enveloped viruses that are formed by infected cells budding and surrounded by pieces of the cell's plasma membrane. Antigens are successfully integrated into liposomes based on their lipophilicity. Liposomal formulations include a wide range of antigens, such as toxoids, viral antigens, and bacterial antigens that display intensive humoral immune responses. Mechanistic studies offer insights into the adjuvanticity of liposomes. Additionally, liposomes have the ability to promote the development of T-cell-independent B-cell immune responses and induce long-term immunity through T-cell memory.
Fig.1 Schematic representation of liposomes. (Tenchov, et al., 2021)
CD BioGlyco has successfully developed a versatile liposomal vaccine carrier with multiple functions through our extensive research in glycobiology. Our liposomal carrier has the ability to encapsulate polysaccharide content. And it non-covalently attaches protein units to the surface of liposomes.
We want to help clients to overcome the challenges posed by the chemical conjugation techniques used in current pneumococcal vaccines. As a consequence, CD BioGlyco is developing a liposome-based vaccine targeting Streptococcus pneumoniae. This offers a two-pronged method for protection against bacterial infection.
Our liposomal vaccine mimics the effect of current pneumococcal vaccines. It achieves this by encapsulating S. pneumoniae polysaccharides within the liposome and attaching protein units to the liposome's surface through non-covalent interactions. This way effectively stimulates a robust and long-lasting immune response. Additionally, the dual-antigen format simplifies the inclusion of numerous polysaccharide and protein components. That broadens the vaccine's coverage by incorporating polysaccharide antigen variants from various S. pneumoniae serotypes. It directs immune reactivity to multiple stages of bacterial pathogenesis through the non-covalent localization of antigens on the surface of liposomes. Lastly, the non-covalent attachment mechanisms utilized in our liposomal constructs, such as metal chelation or biotin affinity, offer flexibility in swapping polysaccharide and protein components. Economically, this simplifies the final vaccine formulation compared to current methods that require covalent chemical conjugation.
Fig.2 Preparation procedure of liposome-based vaccine. (CD BioGlyco)
CD BioGlyco stands at the forefront in the field of glycoscience. Our distinguished experts specialize in glycobiology and lead our team to design diverse carriers for Carbohydrate-based Vaccine Development based on our Glyco™ Vaccine Development Platform. We tackle the problems in bacterial infection research with ingenuity, developing effective vaccines. If our services capture your interest, feel free to contact us without hesitation for additional and detailed information.
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