Creative Biolabs is one of the well-recognized experts who are professional in supporting a broad range of single domain antibody (sdAb) development projects. Along with over a decade of extensive experience in developing novel sdAbs, our scientists are proud to tailor and conduct the best-fit proposal to meet your specific project requirements.

Multivalent sdAb Development

The development of sdAb technology presents great impact on medicine. In order to further improve desired potency and properties, the development of multivalent sdAb provides various alternative antibody formats with modified architectures.

Compared with conventional antibodies, sdAb presents great advantages thanks to its small size (12-15 kDa). However, the small size and monovalent binding also result in rapid blood clearance, fast off-rates, and poor retention times in therapy. In this case, the multivalent sdAb enables the modification of avidity, specificity, size, tumor penetration, and also optimized half-life.

sdAb Humanization

With beneficial pharmacologic and pharmacokinetic properties, sdAbs present great potential in the treatment and diagnosis of various diseases. While the camelid or non-human origin may cause potential immunogenic issues. To overcome this risk, Creative Biolabs provides an elegant HuSdL™ humanization platform that can almost eliminate the immunogenicity of a sdAb to humans while retaining its specificity and affinity. It is a novel solution to develop therapeutic sdAbs for human use.

Creative Biolabs has developed various methods for humanization of non-human sdAbs, which including but not limited to:

• CDR (complementarity determining region) grafting combined with the back-mutation method.
• SDR (specificity determining residue) grafting.

sdAb Affinity Maturation

Although in most cases, the sdAbs isolated from gene synthesis, naïve, or immunized libraries present reasonable affinity, it is still desirable to increase their affinity. Creative Biolabs has developed quantitative library sorting method via phage display or yeast surface display technology to improve the affinity of sdAbs.

In addition, the unique DNA mutagenesis technique provided by Creative Biolabs enables a huge number of variants of the parental sdAb with defined positions mutated. Combined with our advanced phage display sdAb construction and screening technologies, we are proud to achieve 10-100 fold increase in affinity for low-affinity sdAbs.

sdAb Stability Improvement

Compared with conventional antibodies, sdAbs present better characteristics including small size, high affinity, and simple production. However, the stability is still an important factor especially for the sdAbs derived from human VH and VL domain.

The sdAbs stability can be defined by two concepts, chemical stability (proteolytic stability) and physical stability (thermodynamic stability). Creative Biolabs now has developed two efficient methods to improve the stability of sdAbs.

sdAb Conjugation

Bioconjugation is a chemical strategy process to form a stable covalent link between two molecules and results in diverse functionalities including revealing enzyme function, specific biomarkers, determining protein biodistribution, and tracking cellular actions. Compared with conventional antibodies, sdAbs present great advantages, such as small size and high affinity. It has been found that conjugated sdAbs play an important role in therapeutics and diagnostics.

Alternative sdAb Conjugation Services

1. sdAb biotinylation service
2. sdAb-enzyme conjugation service
3. sdAb-fluorophore conjugation service
4. sdAb-gold nanoparticle labeling service
5. sdAb PEGylation service
6. sdAb-polystyrene beads labeling service
7. sdAb-quantum dots conjugation service

sdAb-Drug Conjugate Development

Compared to the conventional therapeutic approaches, the monoclonal antibody-based immunotherapies show great advantages against various infectious diseases and cancers. With high specificity and affinity to the target, antibody-drug conjugates (ADCs) expand the therapeutic window of the conjugated drugs (payloads). With the small size and higher stability, the sdAbs further improve the efficiency and applications of ADCs.

The sdAb-drug conjugates include three components, the sdAbs, a cytotoxic payload, and a molecular linker. Now Creative Biolabs provides the one-stop sdAb-drug conjugate development service to help create highly customized ADCs.

sdAb-based CART Development

Chimeric antigen receptors (CARs), also named as chimeric T cell receptors, chimeric immunoreceptors or artificial T cell receptors, enable immune effector cells (usually T cells or NK cells) to recognize target cells with the corresponding antigen and exercise their cytotoxic activity.

The sdAb-based CART mainly consists of the sdAb, a transmembrane domain, an extracellular hinge, and an internal signaling domain. Based on our cutting-edge platform, we are able to generate CART efficiently.

Creative Biolabs is a leading service provider that focuses on sdAb development. Equipped with advanced platforms and powerful technologies, we are confident in offering the best sdAb development services for our customers all over the world. If you are interested in our service, please feel free to contact us for more details.

All services are provided for research purposes only. Our services cannot be used for clinical or therapeutic applications.