A series of thermo-sensitive hydrogels were designed and synthesized via radical polymerization of N-isopropylacrylamide (NIPAAm) by using a biodegradable acryloyl-poly(-caprolactone)-2-hydroxylethyl methacrylate (AC-PCL-HEMA) as a cross-linker.The influence of temperature on the equilibrium swelling ratio and the optical transmittance of the hydrogel was studied.The in vitro release of parathyroid hormone related peptide (PTHrP) which can increase the number and viability of osteoblasts and promote bone formation

from the hydrogel was investigated.The release profiles indicated that the sustained release of PTHrP from the smart hydrogel was over 13 days

indicating that the materials have potential applications in the field of oral implantology.