Skip to main page content
U.S. flag

An official website of the United States government

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2009 Apr;15(4):923-33.
doi: 10.1089/ten.tea.2007.0407.

Injectable in situ-forming pH/thermo-sensitive hydrogel for bone tissue engineering

Affiliations

Injectable in situ-forming pH/thermo-sensitive hydrogel for bone tissue engineering

Hea Kyung Kim et al. Tissue Eng Part A. 2009 Apr.

Abstract

We developed a novel pH- and thermo-sensitive hydrogel as a scaffold for autologous bone tissue engineering. We synthesized this polymer by adding pH-sensitive sulfamethazine oligomers (SMOs) to both ends of a thermo-sensitive poly(epsilon-caprolactone-co-lactide)-poly(ethylene glycol)-poly(epsilon-caprolactone-co-lactide) (PCLA-PEG-PCLA) block copolymer, yielding a pH/thermo-sensitive SMO-PCLA-PEG-PCLA-SMO block copolymer. The synthesized block copolymer solution rapidly formed a stable gel under physiological conditions (pH 7.4 and 37 degrees C), whereas it formed a sol at pH 8.0 and 37 degrees C, making it injectable. This pH/thermo-sensitive hydrogel exhibited high biocompatibility in a Dulbecco's modified Eagle's medium extract test. Under physiological conditions, the hydrogel easily encapsulated human mesenchymal stem cells (hMSCs) and recombinant human bone morphogenetic protein-2 (rhBMP-2), with encapsulating efficiencies of about 90% and 85%, respectively. To assay for ectopic bone formation in vivo, we subcutaneously injected a polymer solution containing hMSCs and rhBMP-2 into the back of mice, after which we could observe hMSC differentiation for up to 7 weeks. Histological studies revealed mineralized tissue formation and high levels of alkaline phosphatase activity in the mineralized tissue. Therefore, this pH/thermo-sensitive SMO-PCLA-PEG-PCLA-SMO block copolymer demonstrated potential as an injectable scaffold for bone tissue engineering, with in situ formation capabilities.

PubMed Disclaimer

Similar articles

Cited by

Publication types

LinkOut - more resources