Apatite-Coated Collagen Scaffold for Bone Morphogenetic Protein-2 Delivery

• Published in: Tissue engineering. Part A Vol. 17; no. 17-18; pp. 2153 - 2164
• Main Authors: Yang, Hee Seok, La, Wan-Geun, Bhang, Suk Ho, Lee, Tae-Jin, Lee, Minhyung, Kim, Byung-Soo
• Format: Journal Article
• Language: English
• Published: United States Mary Ann Liebert, Inc 01.09.2011
• Subjects: Analysis; Animals; Apatites - chemistry; Bone Morphogenetic Protein 2 - chemistry; Bone morphogenetic proteins; Bones; Collagen; Collagen - chemistry; Collagen - ultrastructure; Mice; Microscopy, Electron, Scanning; Original Articles; Physiological aspects; Proteins; Tissue Engineering; Tissue Scaffolds - chemistry; X-Ray Diffraction; South Korea
• ISSN: 1937-3341; 1937-335X
• DOI: 10.1089/ten.tea.2010.0702

Bone morphogenetic proteins (BMPs) are the most potent osteoinductive growth factors. BMP-2 is clinically used for spine fusion and bone fracture healing. Commercially available BMP-2 uses a type I collagen scaffold as a carrier, but it only releases BMP-2 for a short period of time, which may release the bone formation efficacy. In the present study, we hypothesize that apatite coating of a collagen scaffold increases the release period as well as the osteogenic efficacy of BMP-2. Apatite coating was achieved by incubating collagen scaffolds in simulated body fluids (SBFs). Apatite coating on collagen scaffolds was confirmed by X-ray diffraction, electron spectroscopy for chemical analysis, attenuated total reflectance-Fourier transform infrared spectroscopy, and scanning electron microscopy. The rate and period of BMP-2 release from apatite-coated collagen scaffolds varied depending on the concentration of SBFs used. The 5× and 10× SBF apatite-coated collagen scaffolds released 91.8%±11.5% and 82.2%±13.1% of their loaded BMP-2 over 13 days in vitro , respectively, whereas noncoated collagen scaffold released 98.3%±2.2% over the initial one day. BMP-2 released from apatite-coated collagen scaffold significantly increased the alkaline phosphatase activity of cultured osteoblasts, compared with BMP-2 released from noncoated collagen scaffold. Computed tomography and histomorphometry showed that BMP-2 delivery using apatite-coated collagen scaffolds resulted in 2.5-fold higher bone formation volume and 4.0-fold higher bone formation area than BMP-2 delivery using noncoated collagen scaffolds. This study shows that simple apatite coating of a collagen scaffold results in a BMP-2 carrier that renders long-term release of BMP-2 and dramatically enhances osteogenic efficacy.