INTRODUCTION: Hydrogels have been widely studied as tissue engineering scaffolds 
over the past 2 decades because of their favorable biological properties. 
Recently, a new biodegradable glycol chitin-based thermoresponsive hydrogel 
scaffold (GC-TRS) was developed that can be easily applied as a mild viscous 
solution at room temperature but quickly transforms into a durable hydrogel 
under physiological conditions. The aim of this study was to investigate the 
effects of GC-TRS on the proliferation and odontogenic differentiation of 
colony-forming human dental pulp cells (hDPCs) in the presence of enamel matrix 
derivative.
METHODS: Glycol chitin was synthesized by N-acetylation of glycol chitosan. The 
morphology of the thermoresponsive hydrogel scaffold was observed by using 
scanning electron microscopy. The sol gel phase transition of the aqueous 
solution of glycol chitin was investigated by using the tilting method and 
rheometer studies. hDPCs were isolated based on their ability to generate 
clonogenic adherent cell clusters. The effect of GC-TRS and collagen on cell 
viability was examined by performing 
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. 
Expression of markers for odontogenic/osteogenic differentiation (ie, dentin 
sialophosphoprotein, dentin matrix protein-1, osteonectin, and osteopontin) was 
analyzed by performing real-time polymerase chain reaction.
RESULTS: GC-TRS exhibited a highly macroporous and well-interconnected porous 
structure. The polymer solution existed in a mildly viscous sol state, but it 
transitioned to a gel state and did not flow above approximately 37°C. Rheometer 
studies showed that the glycol chitin solution exhibited a fast sol gel 
transition approximately at body temperature. GC-TRS and collagen did not 
inhibit cell viability until 7 days. Dentin sialophosphoprotein and dentin 
matrix protein-1 were expressed by cells cultured in GC-TRS at a higher level 
than that in cells cultured in collagen (P < .05). In both the scaffold groups, 
dentin sialophosphoprotein, dentin matrix protein-1, and osteopontin messenger 
RNA was up-regulated significantly in EMD-treated hDPCs when compared with the 
nontreated cells (P < .05).
CONCLUSIONS: GC-TRS allowed the proliferation and odontogenic differentiation of 
hDPCs. Furthermore, the differentiation was facilitated by EMD. These results 
suggest that GC-TRS has the potential to be used in tissue engineering 
techniques for dentin regeneration.