Comparison between heparin-conjugated fibrin and collagen sponge as bone morphogenetic protein-2 carriers for bone regeneration.
Bone morphogenetic protein-2 (BMP-2) is used to promote bone regeneration. However, the bone regeneration ability of BMP-2 relies heavily on the delivery vehicle. Previously, we have developed heparin- conjugated fibrin (HCF), a vehicle for long-term delivery of BMP-2 and demonstrated that long-term delivery of BMP-2 enhanced its osteogenic efficacy as compared to short-term delivery at an equivalent dose. The aim of this study was to compare the bone-forming ability of the BMP-2 delivered by HCF to that delivered by clinically utilized BMP-2 delivery vehicle collagen sponge. An in vitro release profile of BMP-2 showed that HCF released 80% of the loaded BMP-2 within 20 days, whereas collagen sponge released the same amount within the first 6 days. Moreover, the BMP-2 released from the HCF showed significantly higher alkaline phosphatase activity than the BMP-2 released from collagen sponge at 2 weeks in vitro. Various doses of BMP-2 were delivered with HCF or collagen sponge to mouse calvarial defects. Eight weeks after the treatment, bone regeneration was evaluated by computed tomography, histology, and histomorphometric analysis. The dose of BMP-2 delivered by HCF to achieve 100% bone formation in the defects was less than half of the BMP-2 dose delivered by collagen sponge to achieve a similar level of bone formation. Additionally, bone regenerated by the HCF-BMP-2 had higher bone density than bone regenerated by the collagen sponge-BMP-2. These data demonstrate that HCF as a BMP-2 delivery vehicle exerts better osteogenic ability of BMP-2 than collagen sponge, a clinically utilized delivery vehicle.
School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea     Bio-Max Institute, Institute of Chemical Process, Engineering Research Institute, Seoul National University, Seoul 151-744, Korea.
Hee Seok
HS
Yang
Wan-Geun
WG
La
Yong-Min
YM
Cho
Wangsoo
W
Shin
Guw-Dong
GD
Yeo
Byung-Soo
BS
Kim
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015519:Bone Density; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage / Q000235:genetics; D001861:Bone Regeneration / Q000235:genetics*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000737:chemistry / Q000378:metabolism; D005337:Fibrin / Q000737:chemistry / Q000378:metabolism; D018014:Gene Transfer Techniques; D006493:Heparin / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D010012:Osteogenesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D024042:Collagen Type I; D005337:Fibrin; D006493:Heparin; D000469:Alkaline Phosphatase