Collagen-Based Osteogenic Nanocoating of Microrough Titanium Surfaces

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Surface Chemistry

Background:

• Titanium implants are widely used in orthopedics and dentistry.
• Enhancing implant osteointegration is crucial for clinical success.
• Controlled delivery of growth factors can improve bone regeneration.

Purpose of the Study:

• To develop a collagen/heparin multilayer coating on titanium surfaces.
• To achieve a retarded release of recombinant human bone morphogenic protein 2 (rhBMP2).
• To enhance the osteogenic activity of implant surfaces.

Main Methods:

• Polyelectrolyte multilayer (PEM) coatings of collagen and heparin were constructed on titanium discs.
• rhBMP2 was incorporated into the PEM coating.
• EDC/NHS chemistry was used for cross-linking to immobilize rhBMP2.
• In vitro assays evaluated rhBMP2 release, Alkaline Phosphatase (ALP) induction in C2C12 cells, and human mesenchymal stem cell (hMSC) proliferation.

Main Results:

• The coating incorporated clinically relevant amounts of rhBMP2 (10.5 µg/disc) without altering surface morphology.
• A retarded release profile was observed, with 14.5% released in 24h and 31.3% over 3 weeks.
• Cross-linking significantly reduced rhBMP2 release.
• The coating significantly increased ALP activity and hMSC proliferation, indicating sustained osteogenic capacity.

Conclusions:

• Collagen/heparin-based PEM nanocoatings can effectively incorporate and control the release of rhBMP2 on titanium surfaces.
• This approach enhances osteogenic activity and cell proliferation, offering a promising strategy for improving dental and orthopedic implant osseointegration.
• The developed coating maintains the bioactivity of rhBMP2 over an extended period.