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Updated: May 3, 2026
Site-Directed Immobilization of Bone Morphogenetic Protein 2 to Solid Surfaces by Click Chemistry
Published on: March 29, 2018
Immobilization of bone morphogenetic protein on DOPA- or dopamine-treated titanium surfaces to enhance
Jeonghwa Kang1, Seiichi Tada2, Takashi Kitajima2
1Nano Medical Engineering Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan ; Department of Biological Science, Tokyo Metropolitan University, Minami-Osawa, Tokyo 192-0938, Japan.
Abstract:
Titanium was treated with 3,4-dihydroxy-L-phenylalanine (DOPA) or dopamine to immobilize bone morphogenetic protein-2 (BMP2), a biomolecule. DOPA and dopamine solutions turned into suspensions, and precipitates were produced at high pH. Both treatments produced a brown surface on titanium that was thicker at high pH than low pH. Dopamine produced a thicker layer than DOPA. The hydrophobicity of the surfaces increased after treatment with dopamine independent of pH. Furthermore, there were more amino groups in the layers formed at pH 8.5 than pH 4.5 in both treatments. Dopamine treatment produced more amino groups in the layer than DOPA. BMP2 was immobilized on the treated surfaces via a coupling reaction using carbodiimide. More BMP2 was immobilized on surfaces treated at pH 8.5 than pH 4.5 in both treatments. The immobilized BMP induced specific signal transduction and alkali phosphatase, a differentiation marker. Thus, the present study demonstrates that titanium treated with DOPA or dopamine can become bioactive via the surface immobilization of BMP2, which induces specific signal transduction.
