Abstract
Acid-treated collagen has the isoelectric point (pI) of approximately 7-9. On the other hand, the pI of the alkali-treated collagen (AC) is shifted to approximately 5 due to the conversion of the glutamine and asparagine residues to glutamic acid and aspartic acid residues, respectively. In our previous study, we showed that AC hydrogel was promising as a sustained-release carrier of basic fibroblast growth factor (bFGF). However, glutaraldehyde, a toxic chemical cross-linker, was used for cross-linking of AC molecules. In this study, we focused on oxidative coupling reaction of feruloyl groups of sugar beet pectin (SBP) catalyzed by horseradish peroxidase. We found that AC and SBP composite hydrogel formed by the enzyme reaction. Optimization of HRP and hydrogen peroxide concentrations resulted in rapid formation of the AC/SBP hydrogel. We confirmed that cytochrome-c, a model for bFGF, electrostatically adsorbed to the composite hydrogel. These results indicate that the AC/SBP hydrogel is promising as injectable gel for sustained-release of bFGF.
