Angiogenic functionalisation of titanium surfaces using nano-anchored VEGF - an in vitro study

Area of Science:

• Biomaterials Science
• Surface Engineering
• Tissue Engineering

Background:

• Titanium implants are widely used in orthopedics and dentistry.
• Enhancing implant osseointegration and vascularization is crucial for clinical success.
• Surface functionalization strategies aim to improve biological responses.

Purpose of the Study:

• To functionalize sandblasted and acid-etched (SAE) titanium surfaces with vascular endothelial growth factor (VEGF).
• To investigate the use of DNA oligonucleotides for VEGF anchorage and controlled release.
• To evaluate the impact of functionalized surfaces on endothelial cell proliferation and biological activity.

Main Methods:

• Conjugating rhVEGF165 to DNA oligonucleotides (ODN).
• Immobilizing complementary ODN anchor strands onto SAE titanium specimens.
• Hybridizing VEGF-conjugated ODN to the immobilized anchor strands.
• Assessing VEGF immobilization, cumulative release, and endothelial cell proliferation (HUVECs).
• Evaluating the biological activity of released VEGF via vWF induction in mesenchymal stem cells.

Main Results:

• Specifically bound VEGF achieved 71.0% immobilization, higher than non-conjugated VEGF controls.
• Cumulative release of specifically bound VEGF was 54.0% after 4 weeks.
• Significantly increased proliferation of HUVECs on surfaces with specifically bound VEGF.
• Released conjugated VEGF demonstrated biological activity, inducing vWF in stem cells.

Conclusions:

• Angiogenic functionalization of SAE titanium surfaces is achievable using VEGF-conjugated ODN anchored via complementary ODN strands.
• The functionalized surfaces promote endothelial cell proliferation and exhibit sustained release of bioactive VEGF.
• This approach offers a promising strategy for enhancing the angiogenic potential of titanium implants.