Regulating the osteogenic function of rhBMP 2 by different titanium surface properties

Abstract

Bone morphogenetic protein 2 (BMP-2) is important for regulating the osteogenic differentiation of mesenchymal stem cells and the response of bone tissue. It adsorbs on the surface of biomedical implants immediately and plays a role of mediator between the materials surfaces and the host cells. Studies usually connect the material surface properties and the new bone formation directly. However, interaction between the adsorbed BMP-2 on the implant surface and the cells in the tissue is the key to explaining the osteogenic properties of the material. So, in this article, we investigated the conformational and functional changes induced by the surface modified titanium metals. We found that the α-helix and β-sheet structure of rhBMP-2 can be well maintained on the anodic oxidation treated titanium surface. The osteogenic function of rhBMP-2 can sustain for a relatively long time even though there is less amount adhere to the surface compared with that on the acid alkali treated titanium. Surface properties, especially the morphology enable a larger amount of rhBMP-2 to adsorb to the surface of the acid alkali treated titanium, but the conformation of the protein is severely influenced. The percentage of α-helix structure is also significantly decreased so that the efficacy of rhBMP-2 is only maintained in the early time. This study indicated that different surface modification of the surface could regulate the structure of rhBMP-2 and then further influence its osteogenic function. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1882-1893, 2016.

TGF‐β activity in acid bone lysate adsorbs to titanium surface

“…BMPs can adsorb to titanium, 44,45 we have not detected BMPs in ABL by proteomic analysis. 15 Thus, bone-derived BMPs might adsorb to titanium but the concentration is below the threshold that causes a cellular response such as activation of the BMP-target gene ID2 (data not shown) and the osteogenic differentiation markers alkaline phosphatase and osteopontin.…”

“…This knowledge, however, does not necessarily mean that TGF‐β activity of ABL exclusively binds to titanium and resists extensive washing. Even though bone contains BMPs and recombinant BMPs can adsorb to titanium, we have not detected BMPs in ABL by proteomic analysis . Thus, bone‐derived BMPs might adsorb to titanium but the concentration is below the threshold that causes a cellular response such as activation of the BMP‐target gene ID2 (data not shown) and the osteogenic differentiation markers alkaline phosphatase and osteopontin.…”

Effect of Novel Micro-Arc Oxidation Implant Material on Preventing Peri-Implantitis

“…This treatment technology has been widely used in biomedical titanium improvement [48,50,51]. Our novel modified micro-arc oxidation, which was optimized according to surface color, microstructure, and biological activity [23,52], had a uniform surface (Figure 1). In addition, in our previous study, it proved to have better osteogenic characteristics [23,24].…”

“…Our novel modified micro-arc oxidation, which was optimized according to surface color, microstructure, and biological activity [23,52], had a uniform surface (Figure 1). In addition, in our previous study, it proved to have better osteogenic characteristics [23,24]. Moreover, MAO titanium has no risk of surface shedding, such as that of HA titanium, and has no particle residual, such as that of SLA titanium.…”

“…HA was first sandblasted and then plasma-sprayed with 30 µm of hydroxyapatite. The machined technique was mechanically polished in sequence with grit SiC paper (#180, #400, #800, #1200) [23]. The novel MAO was connected to the anode of an anodizing device and immersed into a 1 mol·L −1 H 2 SO 4 solution for anodic oxidation treatment by applying a DC voltage of 70 V for 1 min [24].…”