Heprasil™

Heprasil™

Heprasil™ is thiol-modified hyaluronic acid with thiol-modfied heparin and is a component of the Extracel-HP™ and Extracel-HPG™ hydrogel kits. Hyaluronic acid is a major constituent of native extracellular matrix (ECM). Heparin is also present in the ECM as heparan sulfate. Most cells do not attach to Heprasil-only hydrogels1. Heprasil™ must be used in conjunction with Gelin-S™ or ECM proteins such as laminin, collagen, or fibronectin for most 3-D cell culture and tissue-engineering applications2. Heprasil™ can be purchased separately from the hydrogel kits in individual vials.

Gelation

Reconstituted Heprasil™ remains liquid at 15 to 37°C. Without crosslinker, Heprasil™ will form a hydrogel via disulfide bond formation; however, the gelation time is over twenty-four hours. If Extralink™ is used to crosslink the Heprasil, the gelation time is about twenty minutes with no low-temperature or low-pH steps. Diluting Heprasil™ with phosphate-buffered saline (PBS) or cell-culture medium can increase its gelation time

Volume

Heprasil™ vials come in three sizes:

  1. 1 mL
  2. 5 mL
  3. 9 mL

Hyaluronic-Acid Source

The hyaluronic acid (HA) used to produce Heprasil™ is made by a proprietary bacterial fermentation process using bacillus subtilis as the host in an ISO 9001:2000 process (http://www.biopolymer.novozymes.com/). The HA is 100% free of animal-derived raw materials and organic solvents remnants. No animal-derived ingredients are used in its production and it has very low protein levels and no exotoxins. Its production follows the European Pharmacopoeia.

Heparin Source

The heparin, Heparin A, used to produce Heprasil™ is a sodium salt of heparin derived from porcine intestinal mucosa. Heparin A is a mixture of polyanion chains in a relatively wide range of molecular weights (17,000-19,000 Da). (http://www.sigmaaldrich.com/catalog/search/ProductDetail/SIAL/H9399)

References

  1. X. Z. Shu, Y. Liu, F. Palumbo, Y. Luo, G. D. Prestwich, “In Situ Crosslinkable Hyaluronan Hydrogels for Tissue Engineering,” Biomaterials, 25, 1339-1348 (2004).
  2. X. Z. Shu, S. Ahmad, Y. Liu, and G. D. Prestwich, “Synthesis and Evaluation of Injectable, In Situ Crosslinkable Synthetic Extracellular Matrices (sECMs) for Tissue Engineering,” J. Biomed Mater. Res. A, 79A(4), 901-912 (2006).