TY - JOUR
T1 - Injectable in situ-forming pH/thermo-sensitive hydrogel for bone tissue engineering
AU - Kim, Hea Kyung
AU - Shim, Woo Sun
AU - Kim, Sung Eun
AU - Lee, Kweon Haeng
AU - Kang, Eunah
AU - Kim, Jong Ho
AU - Kim, Kwangmeyung
AU - Kwon, Ick Chan
AU - Lee, Doo Sung
PY - 2009/4/1
Y1 - 2009/4/1
N2 - 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(ε-caprolactone-co-lactide)-poly(ethylene glycol)-poly(ε- 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°C), whereas it formed a sol at pH 8.0 and 37°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.
AB - 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(ε-caprolactone-co-lactide)-poly(ethylene glycol)-poly(ε- 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°C), whereas it formed a sol at pH 8.0 and 37°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.
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U2 - 10.1089/ten.tea.2007.0407
DO - 10.1089/ten.tea.2007.0407
M3 - Article
C2 - 19061427
AN - SCOPUS:67049162753
VL - 15
SP - 923
EP - 933
JO - Tissue Engineering - Part A.
JF - Tissue Engineering - Part A.
SN - 1937-3341
IS - 4
ER -