Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural porogen method
Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite porogens fabricated by 3DP. The resolution of printed plaster porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP porogen method provide essential capability for bone tissue engineering.
KeywordsInjection Molding Solid Freeform Fabrication Bone Scaffold Scaffold Fabrication Human Cancellous Bone
We gratefully thank National Science Foundation (NSF) for its financial support (DMI–0300405, CMMI-0700139 and CMMI-0925348). Additionally, the authors are grateful to Dr. Wei Sun for providing access to 3D printer for this study. We also would like to thank the laboratory of Dr. Giuseppe Palmese for assistance with GPC degradation tests and the laboratory of Dr. Boris Polyak for providing the access to plate reader. The Centralized Research Facility (CRF) of the College of Engineering, Drexel University provided access to electron microscopes used in this work.
- 10.Ruhe PQ, Hedberg EL, Padron NT, Spauwen PHM, Jansen JA, Mikos AG. rhBMP-2 release from injectable poly(dl-lactic-co-glycolic acid)/calcium-phosphate cement composites. J Bone Joint Surg Am. 2003;85A:75–81.Google Scholar
- 15.Mikos (AGH, TX), Sarakinos, Georgios (Boston, MA), Vacanti, Joseph P. (Winchester, MA), Langer, Robert S. (Newton, MA), Cima, Linda G. (Lexington, MA). Biocompatible polymer membranes and methods of preparation of three-dimensional membrane structures. United States: Massachusetts Institute of Technology (Cambridge, MA), Children’s Medical Center Corporation (Boston, MA); 1996.Google Scholar
- 18.Zhang W, Yao D, Zhang Q, Zhou JG, Lelkes PI. Fabrication of interconnected microporous biomaterials with high hydroxyapatite nanoparticle loading. Biofabrication. 2010;2.Google Scholar
- 29.Schantz JT, Hutmacher DW, Ng KW, Khor HL, Lim TC, Teoh SH. Evaluation of a tissue-engineered membrane-cell construct for guided bone regeneration. Int J Oral Maxillofac Implants. 2002;17:161–74.Google Scholar