Dual Growth Factor Release From Collagen Based Multilayer Films on Ti-Surfaces Enhances Periimplant Bone Formation...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Research

Background:

• Titanium implants are widely used in orthopedics and dentistry.
• Enhancing periimplant bone formation and vascularization is crucial for implant success.
• Polyelectrolyte multilayer films (PEMs) offer a versatile platform for controlled drug and growth factor delivery.

Purpose of the Study:

• To evaluate the impact of dual growth factor release (rhBMP-2 and rhVEGF165) from PEM-coated titanium implants on bone formation and angiogenesis.
• To investigate the effect of simultaneous versus single growth factor release on periimplant healing in a minipig mandible model.

Main Methods:

• Disc-shaped titanium implants were coated with PEMs loaded with rhBMP-2, rhVEGF165, or both.
• Implants were inserted into minipig mandibles and assessed at 4 and 13 weeks for bone formation, bone-implant contact, and CD31 expression (angiogenesis marker).
• Uncoated and unloaded implants served as controls.

Main Results:

• At 4 weeks, PEMs with VEGF and BMP individually increased CD31 expression, but no significant differences in bone formation or contact were observed.
• At 13 weeks, simultaneous release of rhBMP-2 and rhVEGF165 from PEMs significantly enhanced bone implant contact and bone formation.
• All PEM-coated implants with growth factors showed increased CD31 expression, indicating enhanced angiogenesis.

Conclusions:

• Simultaneous release of rhBMP-2 and rhVEGF165 is necessary for significant improvements in periimplant bone formation and bone-implant contact.
• Both rhVEGF165 and rhBMP-2 enhance angiogenesis (CD31 expression) similarly, without an additive effect from simultaneous release.