Bone morphogenetic protein release from polyelectrolyte multilayers for orthopedic applications: Effect of multilayer deposition conditions

摘要

For all coatings, 50% of BMP-2 release occurred within the first three days, suggesting that similar release mechanisms are at play in all systems. Different amounts of release may primarily result from the different amounts of adsorption that can occur under different conditions. This possibility will be investigated in future work. ALP enzyme activity results are most promising for the modified coatings. Interestingly, the addition of growth factor does not have a statistically significant effect on ALP enzyme activity for the pH=6 deposition condition. Additionally, the coatings made under different processing conditions are significantly more effective than the BMP-2-eluting coating prepared from unmodified solutions. Since the chemistries of these three systems are identical, there must be differences in surface roughness that play a significant role in preosteoblast differentiation and tissue formation. Ongoing work is focused on measuring and controlling surface roughness. These results suggest that coating roughness can play a greater role than growth factor release on tissue formation. Additionally, roughness optimization combined with controlled release of growth factors may result in systems capable of better fixation than systems with just one of those properties.