| Here, we fabricated thermosensitive injectable hydrogel containing poly (N-isopropylacrylamide) (PNIPAAm)-
based copolymer/graphene oxide (GO) composite with different feed ratio to chitosan (CS) as a natural polymer
through physical and chemical crosslinking for the proliferation and differentiation of the human dental pulp
stem cells (hDPSCs) to the osteoblasts. The PNIPAAm copolymer/GO composite was synthesized by freeradical
copolymerization of (N-isopropylacrylamide) (NIPAAm), itaconic acid (IA) and maleic anhydridemodified
poly(ethylene glycol) (PEG) in the presence of GO and used for the preparation of the hydrogels. The
formulated hydrogels were evaluated for the porous architecture, rheological behavior, compressive strength,
swelling property, in vitro degradation, hemocompatibility, biocompatibility, and differentiation. The hydrogel
could enhance the deposition of minerals and the activity of alkaline phosphatase (ALP), in large part attributable
to the oxygen and amine-containing functional groups of GO and CS. The engineered hydrogel could also upregulate
the expression of the Runt-related transcription factor 2 and osteocalcin in the hDPSCs cultivated in both
the normal and osteogenic media. It seems to promote the absorption of osteogenic inducer too. Based on our
findings, the engineered hydrogel demonstrated the osteogenic potential, upon which it is proposed as a constructing
scaffold in bone tissue engineering for the transplantation of hDPSCs. |