title: The effect of immobilization of heparin and bone morphogenic protein-2 to bovine bone substitute on osteoblast-like cell's function.
abstract: OBJECTIVE
  This study was performed to investigate the ability of recombinant human-bone morphogenic protein-2 immobilized on a heparin-grafted bone substrate to enhance the osteoblastic functions.
  
  
  METHODS
  The Bio-Oss®, not coated with any material, was used as a control group. In rhBMP-2-Bio-Oss® group, rhBMP-2 was coated with Bio-Oss® using only deep and dry methods (50 ng/mL, 24 h). In heparinized rhBMP-2-Bio-Oss® group, dopamine was anchored to the surface of Bio-Oss®, and coated with heparin. rhBMP-2 was immobilized onto the heparinized- Bio-Oss® surface. The release kinetics of the rhBMP-2-Bio-Oss® and heparinized rhBMP-2-Bio-Oss® were analyzed using an enzyme-linked immunosorbent assay. The biological activities of the MG63 cells on the three groups were investigated via cytotoxicity assay, cell proliferation assay, alkaline phosphatase (ALP) measurement, and calcium deposition determination. Statistical comparisons were carried out by one-way ANOVA test. Differences were considered statistically significant at (*)P<.05 and (**)P<.001.
  
  
  RESULTS
  The heparinized rhBMP-2-Bio-Oss® showed more sustained release compared to the rhBMP-2-Bio-Oss® over an extended time. In the measurement of the ALP activity, the heparinized group showed a significantly higher ALP activity when compared with the non-heparinized groups (P<.05). The MG63 cells cultivated in the group with rhBMP-2 showed increased calcium deposition, and the MG63 cells from the heparinized group increased more than those that were cultivated in the non-heparinized groups.
  
  
  CONCLUSIONS
  Heparin increased the rhBMP-2 release amount and made sustained release possible, and heparinized Bio-Oss® with rhBMP-2 successfully improved the osteoblastic functions.
authors: Department of Prosthodontics, School of Dentistry, Pusan National University, Yangsan, Korea.
authors: Jung-Bo
authors: JB
authors: Huh
authors: Sung-Eun
authors: SE
authors: Kim
authors: Se-Kyung
authors: SK
authors: Song
authors: Mi-Jung
authors: MJ
authors: Yun
authors: Ji-Suk
authors: JS
authors: Shim
authors: Jeong-Yol
authors: JY
authors: Lee
authors: Sang-Wan
authors: SW
authors: Shin