Heparin modification of calcium phosphate bone cements for VEGF functionalization

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Local and sustained delivery of angiogenic factors is crucial for engineered tissue angiogenesis.
• Vascular Endothelial Growth Factor (VEGF) is a key angiogenic factor.
• Biocement D (BioD) functionalized with VEGF shows potential, but unmodified BioD/coll composites exhibit a high initial VEGF burst release.

Purpose of the Study:

• To investigate the effect of heparin modification on VEGF release from BioD/coll composites.
• To evaluate the impact of heparin on the biological activity and material properties of BioD/coll.
• To assess the clinical applicability of heparin-modified BioD/coll for enhanced tissue regeneration.

Main Methods:

• Modification of BioD/coll composites with varying concentrations of heparin.
• In vitro assessment of VEGF release kinetics and biological activity.
• Evaluation of endothelial cell adhesion and material characterization (microstructure, surface area, compressive strength, rheology).

Main Results:

• Heparin addition significantly reduced the initial burst release of VEGF in a concentration-dependent manner.
• Heparin modification improved the biological activity of released VEGF and enhanced endothelial cell adhesion.
• Heparin-modified composites exhibited a finer microstructure and higher specific surface area, but reduced compressive strength with higher heparin content.
• Rheological properties remained favorable for clinical handling.

Conclusions:

• Heparin is effective in controlling VEGF release kinetics and enhancing biological activity from BioD/coll composites.
• Heparin modification improves the pro-angiogenic potential of BioD/coll for tissue engineering applications.
• Balancing heparin concentration is necessary to optimize material properties and mechanical strength for clinical use.