Evaluation of sustained drug delivery for bone morphogenetic protein on the functionalized nanotubular surface

An effective loading method of the recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) on the implant surface is essential for promoting bone formation. However, the studies comparing the effectiveness of loading methods for rhBMP-2 are insufficient. The objective of this study was to investigate the sustained rhBMP-2 delivery on the functionalized nanotubular surface. rhBMP-2 loading method on functionalized nanotubular surface was divided into 3 groups; coating and dry method, vacuum method, lyophilization method. A total of 10 ug rhBMP-2 was loaded into functionalized nanotubular titanium implant surfaces (3.75 mm in diameter and 7 mm in length). The releasing time of rhBMP-2 was evaluated at 1, 5, 7 days. The data were statistically analyzed with one-way ANOVA and a Post Hoc Bonferroni test. A sustained release pattern was observed in each groups and the amount of rhBMP-2 loaded was the highest in the lyophilization group. The results suggest that lyophilization method is effective method to load rhBMP-2 on the functionalized nanotubular surface and the functionalized nanotubular surface could be a sustainable useful carrier of rhBMP-2.