Wettability and drug delivery of micro-nano porous titanium surface

Objective:

This study was performed to evaluate the wettability of anodized titanium surface which has nanotubular structure and to analyze quantitatively transferable rhBMP-2 on each surface in PBS solution.

Methods:

Four different kinds of surface treated titanium discs (machined surface, blasting, machined-anodized, and blasting-anodized, n=10) were fabricated. Three different media were chosen to measure the surface contact angles ; distilled water, plasma and rhBMP-2 solution. After dropping a single drop (0.025ml) of solution, contact angle was measured by use of image analysis system and the picture was taken with the image camera.

To test the possibility of drug delivery, four different kinds of surface treated titanium discs (machined surface, blasting, machined-anodized, and blasting-anodized, n=3) were fabricated. After soaking sample groups in the concentration of 250ng/ml of rhBMP-2 for 24 hours, they were lyophilized for 24 hours, and then the rhBMP-2 on the surface of titanium was melt for 72 hours by PBS. All the extracted solution was analyzed by ELISA (enzyme linked immunosorbent analysis).

Results:

1. The surface with nanotubular structure by anodic oxidation showed better wettability in all three kinds of solution.

2. The best wettability was shown on the blasting-anodized surface, and it was followed by machined-anodized, blasting, and machined surface. All groups appeared similar tendency and the result showed the least difference among the groups in the plasma.

3. The surface with nanotubular structure by anodic oxidation delivered the most amount of rhBMP-2.

4. During 3 days, blasting-anodized surface delivered the most amount of rhBMP-2, and machined-anodized, blasting, and machined surface followed from highest to lowest

Conclusions:

Micro-nano structure of blasting-anodized surface showed the most excellent result of hydrophilicity and the possibility of good carrier for rhBMP-2.

(This study was supported by second stage Brain Korea 21 project for school of dentistry.)