Poly(propylene fumarate) reinforced dicalcium phosphate dihydrate cement composites for bone tissue engineering

• Published in: Journal of biomedical materials research. Part A Vol. 100A; no. 7; pp. 1792 - 1802
• Main Authors: Alge, Daniel L., Bennett, Jeffrey, Treasure, Trevor, Voytik-Harbin, Sherry, Goebel, W. Scott, Chu, Tien-Min Gabriel
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-07-2012; Wiley-Blackwell
• Subjects: Animals; Biocompatible Materials; Biological and medical sciences; Biotechnology; Bone and Bones; Bone Cements; bone tissue engineering; calcium phosphate; Calcium Phosphates - chemistry; composite; Fumarates - chemistry; Fundamental and applied biological sciences. Psychology; Health. Pharmaceutical industry; Industrial applications and implications. Economical aspects; Male; Medical sciences; Miscellaneous; polymer; Polypropylenes - chemistry; Rabbits; rapid prototyping; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Tissue Engineering; Tissue Scaffolds; polymer; Tissue engineering; bone tissue engineering; Calcium phosphate; Fumarate polymer; Composite material; Osteoarticular system; composite; Cement; Rapid prototyping; Biomaterial; Bone; Unsaturated polymer; Biomedical engineering
• ISSN: 1549-3296; 1552-4965
• DOI: 10.1002/jbm.a.34130

Calcium phosphate cements have many desirable properties for bone tissue engineering, including osteoconductivity, resorbability, and amenability to rapid prototyping‐based methods for scaffold fabrication. In this study, we show that dicalcium phosphate dihydrate (DCPD) cements, which are highly resorbable but also inherently weak and brittle, can be reinforced with poly(propylene fumarate) (PPF) to produce strong composites with mechanical properties suitable for bone tissue engineering. Characterization of DCPD–PPF composites revealed significant improvements in mechanical properties for cements with a 1.0 powder to liquid ratio. Compared with nonreinforced controls, flexural strength improved from 1.80 ± 0.19 MPa to 16.14 ± 1.70 MPa, flexural modulus increased from 1073.01 ± 158.40 MPa to 1303.91 ± 110.41 MPa, maximum displacement during testing increased from 0.11 ± 0.04 mm to 0.51 ± 0.09 mm, and work of fracture improved from 2.74 ± 0.78 J/m2 to 249.21 ± 81.64 J/m2. To demonstrate the utility of our approach for scaffold fabrication, 3D macroporous scaffolds were prepared with rapid prototyping technology. Compressive testing revealed that PPF reinforcement increased scaffold strength from 0.31 ± 0.06 MPa to 7.48 ± 0.77 MPa. Finally, 3D PPF–DCPD scaffolds were implanted into calvarial defects in rabbits for 6 weeks. Although the addition of mesenchymal stem cells to the scaffolds did not significantly improve the extent of regeneration, numerous bone nodules with active osteoblasts were observed within the scaffold pores, especially in the peripheral regions. Overall, the results of this study suggest that PPF–DCPD composites may be promising scaffold materials for bone tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.