About HEPylation™
PEGylation is a Food & Drug Administration-approved process of adding poly[ethylene glycol] (PEG) vehicle to therapeutic ‘cargo’ including small molecule drugs, polypeptides, and liposomes, thus enhancing the physical, chemical, and/or biological nature of a promising drug candidate.  The hydrophilic chains of PEG can help increase solubility in water, protect the cargo when in the human body, and prolong therapeutic action.  For patients, this translates to fewer injections, more even drug levels, and reduced side effects. However, PEG while useful and profitable, has some drawbacks due to its artificial nature and its chemical synthesis. PEG’s degradation products (oxalic acid, reactive aldehydes & ketones), its occasional immunogenicity, and the upper size limit for controlled polymerization are problematic.

HEPylation™ is a new platform technology to add a heparosan polymer vehicle to therapeutic cargo. Heparosan, a natural polysaccharide related to heparin, is a new type of therapeutic modifying agent. The DeAngelis group cloned and harnessed a bacterial heparosan polymerizing enzyme called heparosan synthase, PmHS1, from Pasteurella multocida. A key advance was the use of this catalyst for chemoenzymatic synthesis of sugar polymers with a very narrow size distribution, termed ‘monodisperse’. The method also allows the defined and reproducible chemical activation of heparosan to facilitate monovalent, selective coupling to cargo. Heparosan should be biocompatible and bio-inert in the human body. Even certain pathogenic bacteria use a heparosan coating as molecular camouflage to ‘hide’ during infection. Heparinex, LLC, has licensed the patents for the platform technologies from OUHSC.

HEPylation™ has some potentially superior attributes over PEGylation including:
    a) a larger size range of polymers is more readily synthesized,
    b) more control of size distribution at longer chain lengths,
    c) higher water solubility,
    d) more biocompatible degradation products, and
    e) new intellectual property.

Heparinex was founded upon the discovery of two novel methodologies to produce synthetic heparinoid compounds in a highly controlled manner. Heparin is used as an anticoagulant and antithrombotic agent in a wide variety of medical conditions. Traditional production techniques involve procuring and purifying heparin from sources such as porcine intestine and bovine lung. While the current methods are adequate, they limit the potential applications of heparin due to the inherent variability in the molecular size and weight of the heparin chains. The Heparinex solution circumvents these issues by providing techniques to produce uniform monodisperse heparin chains.