PolyXen® is an enabling technology for protein drug delivery. It uses the natural polymer polysialic acid (PSA) to prolong the active life and improve the stability of therapeutic peptides and proteins. It can also be used for small molecule drugs.
PolyXen® is an enabling technology for protein drug delivery. It uses the natural polymer polysialic acid (PSA) to prolong the active life and improve the stability of therapeutic peptides and proteins. It can also be used for small molecule drugs.
Pre-clinical proof-of-concept studies and clinical studies in man have shown that the key benefits of PolyXen® for protein drug delivery include:
- Preservation of drug functionality on conjugation
- Improved stability in vivo
- Prolonged pharmacological action
- Prolonged active life of the drug in the blood circulation
- Reduced frequency and amount of dosage
- Reduced immunogenicity and antigenicity
What is polysialic acid?
PSA is a polymer of sialic acid (a sugar). When used for therapeutic protein and peptide drug delivery, polysialic acid provides a protective microenvironment following conjugation to the active drug. This increases the active life of the therapeutic drug in the body and prevents it from being recognized by the immune system.
Watch a video explaining our PolyXen® technology
The PSA polymer is naturally found in the human body. However, PSA actually evolved millions of years ago as part of the coat on the external walls of certain bacteria. By virtue of molecular mimicry with human PSA, these naturally polysialylated bacteria are able to foil the body’s defences and can exist largely undetected by the immune system. Xenetic are producing PSA, nature's ultimate stealth technology, from such bacteria in large quantities and with predetermined physical characteristics. Bacterial PSA is an ideal polymer for drug conjugation as it is non-toxic, biodegradable and completely non-immunogenic, even when coupled to proteins, due to it being chemically identical to PSA found in the human body. This is particularly important where a polymer is to be used to deliver therapeutics chronically or in large dosages
How does PolyXen® technology use polysialic acid?
PolyXen® uses proprietary techniques to conjugate polysialic acid molecules of appropriate length to specific sites of the therapeutic molecule, but importantly, away from its active site to preserve activity. The PSA molecules form a glycocalyx (a carbohydrate shield) around the therapeutic rendering it less visible to and reducing the risk of recognition by the body’s immune system.
