Melt Electrowritten Scaffold-Reinforced Affibody-Conjugated Hydrogels for Controlled Bone Morphogenetic Protein-2...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Bone morphogenetic protein-2 (BMP-2) is crucial for bone regeneration but faces challenges with uncontrolled release from collagen sponges, leading to adverse effects.
• Existing hydrogels offer tunable protein release but lack mechanical strength and stability for practical applications.

Purpose of the Study:

• To develop a dual-function hydrogel system for controlled BMP-2 delivery, integrating mechanical reinforcement and affinity-based release.
• To evaluate the efficacy of this system in enhancing bone regeneration and protein retention in vivo.

Main Methods:

• Fabrication of a melt electrowritten (MEW) scaffold-reinforced, affibody-conjugated polyethylene glycol maleimide (PEG-mal) hydrogel.
• Incorporation of BMP-2-specific affibodies for affinity-controlled release and MEW scaffolds for mechanical enhancement.
• Assessment of hydrogel stability, protein release kinetics, and in vivo bone regeneration in rat femoral defects.

Main Results:

• MEW scaffolds improved hydrogel handling, compressive resistance, and stability through lyophilization and rehydration.
• Affibody conjugation enabled tunable BMP-2 release, maintained after lyophilization and rehydration.
• In vivo studies showed enhanced BMP-2 retention, increased bone volume, and improved defect bridging with the reinforced hydrogel system.

Conclusions:

• The developed hydrogel system effectively combines mechanical reinforcement with tunable protein-material affinity interactions for advanced BMP-2 delivery.
• This integrated platform represents a significant advancement for hydrogel-based therapeutic strategies in musculoskeletal repair and other regenerative applications.