Kim, Hea Kyung Shim, Woo Sun Kim, Sung Eun Lee, Kweon-Haeng Kang, Eunah Kim, Jong-Ho Kim, Kwangmeyung Kwon, Ick Chan Lee, Doo Sung 2024-01-20T21:34:28Z 2024-01-20T21:34:28Z 2021-09-03 2009-04 1937-3341 https://pubs.kist.re.kr/handle/201004/132617 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(e-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. English MARY ANN LIEBERT, INC MESENCHYMAL STEM-CELLS MORPHOGENETIC PROTEIN-2 ADIPOSE-TISSUE OSTEOGENIC DIFFERENTIATION DELIVERY PH DEGRADATION SCAFFOLDS MATRICES Injectable In Situ-Forming pH/Thermo-Sensitive Hydrogel for Bone Tissue Engineering Article 10.1089/ten.tea.2007.0407 1 TISSUE ENGINEERING PART A, v.15, no.4, pp.923 - 933 TISSUE ENGINEERING PART A 15 4 923 933 scie scopus 000264892000019 2-s2.0-67049162753 Cell & Tissue Engineering Cell Biology Engineering, Biomedical Materials Science, Biomaterials Cell Biology Engineering Materials Science Article MESENCHYMAL STEM-CELLS MORPHOGENETIC PROTEIN-2 ADIPOSE-TISSUE OSTEOGENIC DIFFERENTIATION DELIVERY PH DEGRADATION SCAFFOLDS MATRICES