Chitosan/Bovine Serum Albumin Co-micropatterns On Titanium Surfaces And Their Biomedical Performance

Despite the great development in improving the osseointegration of titanium implants, the outlook for formation of fully functional new bone after implantation remains dismal. To gain full function of the growing portion of the bone, the bone cells (such as the hard bone and soft bone cells) must navigate correctly through the implant surface-tissue interface to the designed target. Osteoblasts, which are closely associated with bone formation, have been shown to be greatly influenced by surface topography and chemistry. To investigate osteoblast response to surface guidance in the initial implantation stage in vitro, CS/BSA micropatterns on functionalized Ti surfaces were prepared by micro-transfer molding method. Two kinds of micropatterns were produced, namely, (1) microgrooves; (2) microcylinders.After 1,3, and 7 d of culture, the cells were observed by scanning electron microscopy. The MC3T3-E1 osteoblasts cultured on CS/BSA micropatterns were found to spread on the chitosan-rich regions. The BSA-rich region was not completely avoided and osteoblasts were observed to reach adjacent chitosan-rich regions. The quantitative comparison of cell behaviors on the two types of micropatterns indicated that the shape rather than the size appeared to be the dominating influence on cell proliferation. The size of the micropattern in the same range of cell diameters favored cell proliferation. However, cell differentiation was more sensitive to the size of micropatterns than to micro-geometry. The results demonstrate that cell behaviors could be regulated by micropatterns of different materials. The antibacterial test was further performed to evaluate the antibacterial effect of chilosan/BSA co-micropatterns against E. coli and S. aureus. Results show that they had high bactericidal ratio. The findings provide new insights into the mechanism of cell response to the micro-geometry of biomaterial surfaces, and may have a general implications on the micro-geometrical design of biomaterial surfaces.