The quantities of natural bacterial glycans and cancer antigens are limited, which brings difficulties to clinical trials. Synthetic chemistry can save time by mass production of antigens. CD BioGlyco has established a variety of strategies for developing semi-synthetic carbohydrate vaccines.

Semi-synthetic Carbohydrate-based Vaccine

Despite the great medical and commercial advances in isolated polysaccharide-based conjugate vaccines, there are still several insurmountable challenges in their development such as the inability to culture the pathogen or the difficulty of isolating glycans, which limits the procurement of polysaccharides for the production of conjugate vaccines. In addition, even if strains can be cultured, the production of sufficient quantities of the correct CPS requires careful process optimization. Some unstable polysaccharides may decompose during the isolation process. And isolated polysaccharide preparations inevitably contain small amounts of impurities, such as pneumococcal C-polysaccharides not found in synthetic polysaccharides.

Since the late 1980s, methods to synthesize glycan epitopes have been explored. A semi-synthetic glycoconjugate vaccine was developed in Cuba as a Haemophilus influenzae type b vaccine. In this strategy, instead of using a single glycotope, a mixture of oligosaccharides of different lengths was used, which were prepared by polymerizing synthetic building blocks. The coupling of synthetic glycans to tetanus toxoid (TT) carrier protein has produced a semi-synthetic glycoconjugate vaccine that has proven highly effective. To date, no other semi-synthetic vaccines have been marketed due to the limitations of the vaccine industry on new technologies.

Fig.1 The semi-synthetic or fully synthetic glycoconjugate vaccine approach. (Seeberger, 2021)

Our Strategies

CD BioGlyco has established an advanced vaccine research platform to help clients design and produce semi-synthetic carbohydrate vaccines with well-defined antigenic structures with spacer arms, high purity, and a better safety profile. Our strategies include but are not limited to:

• Synthetic glycotope: We modify a variety of factors including glycotope length, glycotope frameshifts, glycan modifications, and unstable epitopes to improve the immunogenicity of the glycans according to the client's diverse scientific requirements.
• Creation of glycoconjugate junctions, which combines the glycan (isolated or synthetic) with a carrier (usually a protein). It commonly includes attachment via a terminal amine and attachment via terminal thiols.

Applications

• Improving existing vaccines
• Developing entirely new modes of protecting humans from bacteria
• Application in preclinical and clinical development
• Control of infectious diseases

Advantages of Us

• Professional research teams
• Products with higher purity and homogeneity
• Simple experimental procedures
• Reliable and detailed service

CD BioGlyco has many successful experiences in carbohydrate-based vaccine development, and the extensive and professional scientific services we provide have brought convenience to our clients around the world. If you are interested in our services, please contact us for more details.

Reference:

1. Seeberger, P.H. Discovery of semi- and fully-synthetic carbohydrate vaccines against bacterial infections using a medicinal chemistry approach: Focus review. Chemical Reviews. 2021, 121(7):3598-3626.