Orthotopic bone formation by implantation of apatite-coated poly(lactide-co-glycolide)/hydroxyapatite composite particulates and bone morphogenetic protein-2
✍ Scribed by Sang-Soo Kim; So-Jung Gwak; Byung-Soo Kim
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 622 KB
- Volume
- 87A
- Category
- Article
- ISSN
- 1549-3296
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✦ Synopsis
Abstract
Bone morphogenetic proteins (BMPs) are the most potent osteoinductive growth factors. However, a delivery system is essential to take advantage of the osteoinductive effect of BMPs. In the present study, we tested the suitability of apatite‐coated poly(D,L‐lactide‐co‐glycolide)/nanohydroxyapatite (PLGA/HA) particulates as carriers for the controlled release of BMP‐2. The release of BMP‐2 from apatite‐coated PLGA/HA particulates was sustained for at least 4 weeks in vitro. A delivery system of apatite‐coated PLGA/HA particulates suspended in fibrin gel further slowed the BMP‐2 release rate. In vivo implantation of either Fibrin gel + BMP‐2 or Fibrin gel + apatite‐coated PLGA/HA particulates showed enhanced new bone formation in critical‐sized calvarial defects of rats 8 weeks after implantation, compared to implantation of fibrin gel only. Importantly, new bone formation was much higher in the defects treated with BMP‐2 delivery using apatite‐coated PLGA/HA particulates in fibrin gel (Fibrin gel + PLGA/HA + BMP‐2 group) than in the defects treated either with apatite‐coated PLGA/HA particulates in fibrin gel (Fibrin gel + BMP‐2 group) or with BMP‐2 delivery using fibrin gel alone (Fibrin gel + BMP‐2 group). BMP‐2 and osteoinductive HA had an additive effect on orthotopic bone formation. In conclusion, the apatite‐coated PLGA/HA particulates showed good results as carriers for BMP‐2. The BMP‐2 delivery system showed high osteogenic capability in a rat calvarial bone defect model. The local and sustained delivery system for BMP‐2 developed in this study may be useful as a carrier for BMP‐2 and would enhance bone regeneration efficacy for the treatment of large bone defects. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008