- Thiol-modified hyaluronan and thiol-modified heparin
- Lyophilized solid for reconstitution in DG water
- Vials are blanketed in argon and under a slight vacuum
- Tested for bacteria, endotoxins, and lactate dehydrogenase-elevating virus (LDEV)
Heprasil® is thiol-modified hyaluronic acid with thiol-modfied heparin and is a component of the Extracel-HP® hydrogel kit. 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.
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
Heprasil® vials come in two sizes:
- 1 mL Vial
- 5 mL Vial
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 solvent remnants. No animal-derived ingredients are used in its production and it has very low protein levels and no exotoxins. It is manufactured by Novozymes and is produced pursuant to the European Pharmacopoeia guidelines.
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). It is produced by Sigma Aldrich Corp.
For research use only
Heprasil® (thiol-modified sodium hyaluronate with thiol-modified heparin) is packaged in 1 mL and 5 mL vials. Vials are blanketed by argon and under a slight vacuum.
- Store Heprasil in the original vial unopened at -20 °C for up to one year.
- Do not uncap the Heprasil vials since it will crosslink in the presence of oxygen. Use a syringe and needle to add DG Water to the vials.
INSTRUCTIONS FOR USE
Heprasil is prepared by dissolving the lyophilized solid in the DG Water. When reconstituted, it will be in 1x phosphate buffered saline (PBS), pH ~7.4. The amount of DG Water used for dissolution depends on the vial.
Heprasil should be prepared in the following manner:
- Allow the Heprasil vial to come to room temperature.
- Under aseptic conditions, using a syringe and needle, add to the vial the amount of DG Water indicated on the label.
- Place the vial horizontally on a rocker or shaker. It will take <30 minutes for the solids to fully dissolve. Warming to 37 °C and/or gently vortexing will speed up dissolving time. Solutions will be clear and slightly viscous.
- Typically, Extralink is used in a 1:4 volume ratio with Heprasil (i.e. 1.0 mL of Heprasil is crosslinked with 0.25 mL of Extralink). Note: the gelation time will be <15 minutes. Hydrogels made using only Heprasil and Extralink will not support cell attachment. Use with Gelin-S for cell attachment.
Note: Product has been manufactured under aseptic conditions and tested for bacteria and fungus.
- 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).
- 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).