Affiliations: Fusion Biotechnology Research Center, Korea Research Institute of Chemical Technology, Yuseong, Daejeon, Korea | Department of Molecular Science and Technology, Ajou University, Suwon, Korea | Laboratory of Tissue Engineering, Korea Institute of Radiological and Medical Sciences, Gongneung-Dong, Nowon-Gu, Seoul, Korea
Note: [] Equal first authors.
Note: [] Address for correspondence: Moon Suk Kim, Department of Molecular Science and Technology, Ajou University, Suwon, Korea. Tel.: +82 31 219 2608; Fax: +82 31 219 3931; E-mail: moonskim@ajou.ac.kr.
Abstract: A number of materials have been considered as sources of grafts to repair bone defects. Here, we examined the possibility of creating in situ-forming gels from sodium carboxymethylcellulose (CMC) and poly(ethyleneimine) (PEI) for use as an in vivo carrier of demineralized bone matrix (DBM). The interaction between anionic CMC and cationic PEI was examined by evaluating phase transition behavior and viscosity of CMC solutions containing 0–30 wt% PEI. CMC solutions containing 10 wt% PEI exhibited a sol-to-gel phase transition at temperatures greater than 35°C. The phase transition is caused by electrostatic crosslinking of the CMC/PEI solution to form a gel with a three-dimensional network structure. In situ-formed gel implants were successfully fabricated in vivo by simple subcutaneous injection of the CMC/PEI (90/10) solution (with and without DBM) into Fisher rats. The resulting in situ-formed implant maintained its shape for 28 days in vitro and in vivo. Our results show that in situ-forming CMC/PEI gels can serve as a DBM carrier that can be delivered with a minimally invasive procedure.
Keywords: Sodium carboxymethylcellulose, poly(ethyleneimine), demineralized bone matrix, in situ gel
