A new recombinant human bone morphogenetic protein-2 carrier for bone regeneration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Biodegradable porous scaffolds are crucial for delivering growth factors in bone regeneration.
• Gelatin sponges offer biocompatibility but require reinforcement for structural stability.
• Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a key osteoinductive factor.

Purpose of the Study:

• To develop and evaluate a novel poly(D,L-lactic-co-glycolic acid)-coated gelatin sponge as a carrier for rhBMP-2.
• To assess the influence of gelatin sponge bulk density on rhBMP-2 incorporation and ectopic bone formation.
• To evaluate the structural stability and biocompatibility of the carrier in vivo.

Main Methods:

• A gelatin sponge was fabricated via foaming and heat treatment, then coated with poly(D,L-lactic-co-glycolic acid).
• rhBMP-2 was incorporated into sponges of varying bulk densities.
• Ectopic bone formation assays in rats were conducted, analyzing calcium content, histology, and peripheral quantitative computed tomography.
• Implant structural integrity was assessed using soft X-ray imaging.

Main Results:

• rhBMP-2 incorporation correlated with gelatin sponge bulk density.
• Calcium content, indicative of bone formation, increased with higher bulk densities.
• Cell infiltration and growth were observed throughout the carrier within 4 weeks, irrespective of bulk density.
• The carrier maintained its 3D structure post-implantation, resisting collapse during bone formation.

Conclusions:

• The developed poly(D,L-lactic-co-glycolic acid)-coated gelatin sponge is a promising biodegradable carrier for rhBMP-2.
• The carrier exhibits suitable structural properties and biocompatibility for bone regeneration applications.
• Sponge bulk density influences rhBMP-2 loading and ectopic bone formation, while structural integrity is maintained.