Preparation of enzymatically cross-linked sulfated chitosan hydrogel and its potential application in thick tissue engineering

For the requirement of preliminary vascularization,the scaffolds for thick tissue engineering should have not only good cell affinity,but also anticoagulant ability.In this paper,enzymatically cross-linked hydrogel scaffolds based on sulfated chitosan(SCTS)were prepared.Firstly,sulfated chitosan-hydroxyphenylpionic acid(SCTS-HPA)conjugate was synthesized,and the structure of SCTS-HPA was identified by FITR and1H NMR.And then the enzymatically cross-linked hydrogels were prepared in presence of horseradish peroxidase(HRP)and hydrogen peroxide(H2O2).The gelation time,mechanical property,morphology and cytotoxicity to human umbilical vein endothelial cells(HUVECs)of the hydrogel were evaluated in vitro,the tissue compatibility of SCTS-HPA scaffold was studied in vivo.The results showed that the gelation time,mechanical property,morphology of the dehydrated hydrogel could be controlled by the the concentration of HRP and H2O2.The cytotoxicity test showed that the hydrogel extracts have no cytotoxicity to HUVECs.The in vivo assay indicated that SCTS-HPA scaffold have good tissue compatibility with no thrombus formation.All these results indicated that the SCTS-HPA scaffold could be used as a thick tissue engineering scaffold.