Sialic Acid Affinity Resins
The adeno-associated virus (AAV) vector has become a promising choice of vehicle for many gene therapies. As AAV-mediated vectors have approached clinical practices, the need for scalable methods of production and purification is steadily increasing. With a high reputation in the field of gene therapy, Creative Biolabs focuses on the utility of purification steps for virus production and devotes to operating various chromatographic modes for AAV purification and process development. Remarkably, we provide a new chromatographic strategy using sialic acid affinity resins to purify AAV vectors, based on a reversible interaction among the viral capsid and biological ligand or receptor.
Affinity Chromatography (AC)
AC is one of the most common and robust separation techniques, achieving the finest purification with high yields. This way separates the molecule of interest from the crude stream by highly specific interactions between the target and immobilized ligand coupled to chromatographic matrixes. For AAV particles, it is capable of eluting viral particles from protein and DNA contaminants of host cells.
Sialic acid resins-based chromatography is ideal for capture or intermediate step in the purification protocol and can be used for certain AAV serotypes whenever a suitable ligand or receptor is available. Purification by affinity resins is valuable due to its high selectivity, high resolution, and high virus binding ability, which leads to considerable recovery of active biomolecules concentrated up to several thousand-fold.
Figure 1. Principle of affinity chromatography. (Zhao, 2019)
Sialic Acid Affinity Resins at Creative Biolabs
Figure 2. Resin chromatographic supports. (Zhao, 2019)
Many AAV serotypes, such as AAV1, AAV4, and AAV5, fail to bind heparin efficiently so that precluding applications of the same product to all serotypes. Therefore, new purification methods are required for these AAV vector types. The observation that 2,3-linked sialic acid is necessary for AAV4 and AAV5 binding, entry, and transduction resulting in the development of a single step AC for AAV5 purification. The affinity matrix for the capture of AAV5 vectors contains a sialic acid-rich protein that is covalently coupled to CNBr-activated sepharose.
The AAV-derived recombinant vector (rAAV) is attracting significant attention as a powerful tool for a range of gene delivery systems, relying on the generation of high-titer, high-purity recombinant vectors. The development of novel rAAV gene transfer vectors of other AAV serotypes brings more considerations to the AAV manufacturing process. At Creative Biolabs, we exploit sialic acid affinity resins to accomplish AAV purification with improved flexibility and productivity. Our versatile services and skillful teams make rAAV readily available for the low budget research and easily adapted for a large-scale GMP production.
Advantages
- Inexpensive, flexible method for AAV purification
- Efficient for specific AAV serotypes (AAV1, AAV4, AAV5, etc.)
- Extended to large-scale viral production
- Simplified process and reduced development timeline
AAV has shown great potential for the delivery of therapeutic genes in gene therapy applications. As a first-class biomedical company, Creative Biolabs has launched a series of novel rapid, low cost, and scalable chromatographic methods for the purification of various rAAV vectors from the lysates of producer cells. The development, our advanced virus vector purification services using sialic acid affinity resins help rAAV technology commercially viable for further virus vector design and development. For more information, please feel free to contact us or directly send us an online inquiry.
Reference
- Zhao, M.; et al. (2019). Affinity chromatography for vaccines manufacturing: finally ready for prime time? Vaccine. 37(36): 5491-5503.
