Bone engineering by phosphorylated-pullulan and beta-TCP composite

作者：Takahata Tomohiro^*; Okihara Takumi; Yoshida Yasuhiro; Yoshihara Kumiko; Shiozaki Yasuyuki; Yoshida Aki; Yamane Kentaro; Watanabe Noriyuki; Yoshimura Masahide; Nakamura Mariko; Irie Masao; Van Meerbeek Bart; Tanaka Masato; Ozaki Toshifumi; Matsukawa Akihiro

来源：Biomedical Materials, 2015, 10(6): 065009.

DOI：10.1088/1748-6041/10/6/065009

• phosphorylated-pullulan
• beta-TCP
• bone formation

A multifunctional biomaterial with the capacity bond to hard tissues, such as bones and teeth, is a real need for medical and dental applications in tissue engineering and regenerative medicine. Recently, we created phosphorylated-pullulan (PPL), capable of binding to hydroxyapatite in bones and teeth. In the present study, we employed PPL as a novel biocompatible material for bone engineering. First, an in vitro evaluation of the mechanical properties of PPL demonstrated both PPL and PPL/beta-TCP composites have higher shear bond strength than materials in current clinical use, including polymethylmethacrylate (PMMA) cement and a-tricalcium phosphate (TCP) cement, Biopex-R. Further, the compressive strength of PPL/beta-TCP composite was significantly higher than Biopex-R. Next, in vivo osteoconductivity of PPL/beta-TCP composite was investigated in a murine intramedular injection model. Bone formation was observed 5 weeks after injection of PPL/beta-TCP composite, which was even more evident at 8 weeks; whereas, no bone formation was detected after injection of PPL alone. We then applied PPL/beta-TCP composite to a rabbit ulnar bone defect model and observed bone formation comparable to that induced by Biopex-R. Implantation of PPL/beta-TCP composite induced new bone formation at 4 weeks, which was remarkably evident at 8 weeks. In contrast, Biopex-R remained isolated from the surrounding bone at 8 weeks. In a pig vertebral bone defect model, defects treated with PPL/beta-TCP composite were almost completely replaced by new bone; whereas, PPL alone failed to induce bone formation. Collectively, our results suggest PPL/beta-TCP composite may be useful for bone engineering.

• 出版日期2015-12
• 单位KU Leuven