Immobilization of Bone Morphogenetic Protein on DOPA- or Dopamine-Treated Titanium Surfaces to Enhance Osseointegration

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.

Mussel-inspired human gelatin nanocoating for creating biologically adhesive surfaces

“…These results are similar to previously reported results for dopamine solutions. 32,33 It is likely that Michael addition or Schiff base reactions are prevalent in the high-pH dopamine solutions, as reported elsewhere. 15 Based on this, we concluded that D-rhG has properties similar to those of dopamine.…”

“…[21][22][23] These treatments not only provide organic layers, but also increase immobilization of biological molecules on the surfaces of various materials. [24][25][26][27][28][29][30][31][32][33] Various methods for dopamine conjugation have been investigated, including direct chemical coupling with polysaccharides. Hyaluronic acid, heparin, and β-cyclodextrin have been conjugated with dopamine or DOPA to increase the adhesiveness of the original polysaccharides.…”

“…Titanium was used as the treated inorganic material because of its widespread application in many biomedical devices. 32,33,40,41 …”

Research Progress on the Biochemical Modification of Titanium Implant Surface

“…Although BMP-2 itself is osteoinductive, its osteogenic potency was markedly enhanced after incorporation into biomimetic calcium phosphate coatings. Jeonghwa et al [36] attempted to immobilize BMPs on dopamine-treated Ti surfaces to enhance osseointegration, and thought the immobilized BMP-2 specifically interacted with myoblasts and induces osteogenic differentiation. Therefore, they proposed that their method was convenient for covalently immobilizing BMP2 while retaining its biological activity.…”

Nanolayer formation on titanium by phosphonated gelatin for cell adhesion and growth enhancement

“…[20][21][22] In addition, as another non-canonical amino acid, phosphonated serine has been applied to underwater adhesion. [23][24][25] Such phosphate groups have been found in the underwater adhesive proteins of the sandcastle worm and caddy silks, 16,17 which interact specifically with a titanium surface.…”