Currently tissue engineering can solve the problem of shortage of donated organs using regenerative techniques of artificial skin, cartilage, bone, bladder, myocardium, liver, etc. In this study, we examined the osteogenic differentiation of human turbinate mesenchymal stem cells (hTMSCs) in vivo by using injectable hydrogel forming electrostatic attraction with bone morphogenetic proteins-2 (BMP2). hTMSCs are easily isolated from inferior turbinate tissue, exhibited abundant and proliferated at a high rate. Also hTMSCs have the ability to differentiate into osteoblasts. Methoxy polyethylene glycol-b-poly(caprolactone)-ran-(3-benzyloxymethyl lactide) diblock copolymer (PCL-Bz) were derivatized by introducing a pendant amine group (PCL-NH2) at the benzyl group. The amine group of PCL-NH2 forms the electrostatic attraction with BMP-2 having a negative charge. Electrostatic attraction reduces initial burst release and increases stability of BMP-2 in PCL-NH2 hydrogel. So we injected PCL-NH2 hydrogel and poly(caprolacton)-ran-(lactide) (PCL) hydrogel which does not make electrostatic attraction with BMP2 into the mice subcutaneous to confirm the bioavailability of BMP-2 by electrostatic attraction. Osteogenic differentiation of hTMSCs was identified by von Kossa (VK) and alizarin red S (ARS) staining of removed hydrogels at 2, 4, 8 weeks and osteonectin, osteopontin, osteocalcin, and collagen type 1α mRNA expression. As a result, PCL-NH2 hydrogel has a slower drug release and more bone formation than PCL hydrogel. In conclusion, PCL-NH2 hydrogel that form electrostatic attraction with growth factors and drugs will be used in many applications in tissue engineering.
