The osteogenesis of bacterial cellulose scaffold loaded with bone morphogenetic protein-2.

Bacterial cellulose (BC) is a nanofibrous biological material with attractive physicochemical properties and biocompatibility. Its fiber is similar to the collagenous fiber of bone. To explore if BC could be utilized as a localized delivery system to increase the local concentration of cytokines for tissue engineering, we prepared the BC scaffold from Acetobacter xylinum X-2 (A. xylinum X-2) and investigated the osteogenic potential of the BC scaffold coated with bone morphogenetic protein-2 (BMP-2). The data showed that BC had a good biocompatibility and induced differentiation of mouse fibroblast-like C2C12 cells into osteoblasts in the presence of BMP-2 in vitro, as demonstrated by alkaline phosphatase (ALP) activity assays. Within a certain range (0 ∼ 3 μg/scaffold), the osteogenic activity of induced osteoblasts was positively correlated to the concentrations of BMP-2. In in vivo subcutaneous implantation studies, BC scaffolds carrying BMP-2 showed more bone formation and higher calcium concentration than the BC scaffolds alone at 2 and 4 weeks, respectively. The ALP activity assay and the measurement of calcium concentration of BC scaffolds also showed that more new bone was developed in the BC scaffolds carrying BMP-2 than in the BC scaffolds alone. Our studies suggest that BC is a good localized delivery system for BMPs and would be a potential candidate in bone tissue engineering.