Effects of designed PLLA and 50:50 PLGA scaffold architectures on bone formation in vivo |
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Authors: | Eiji Saito Elly E Liao Wei‐Wen Hu Paul H Krebsbach Scott J Hollister |
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Institution: | 1. Department of Biomedical Engineering, University of Michigan, Ann Arbor, , Michigan, 48109‐2099 USA;2. Department of Chemical and Materials Engineering, National Central University, , Jhongli, Taoyuan, Taiwan;3. Department of Biologic and Materials Science, School of Dentistry, University of Michigan, Ann Arbor, , Michigan, 48109‐1078 USA;4. Department of Mechanical Engineering, University of Michigan, Ann Arbor, , Michigan, 48109–2125, USA;5. Department of Surgery, University of Michigan, Ann Arbor, , Michigan, 48109‐0329 USA |
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Abstract: | Biodegradable porous scaffolds have been investigated as an alternative approach to current metal, ceramic, and polymer bone graft substitutes for lost or damaged bone tissues. Although there have been many studies investigating the effects of scaffold architecture on bone formation, many of these scaffolds were fabricated using conventional methods such as salt leaching and phase separation, and were constructed without designed architecture. To study the effects of both designed architecture and material on bone formation, this study designed and fabricated three types of porous scaffold architecture from two biodegradable materials, poly (L‐lactic acid) (PLLA) and 50:50 Poly(lactic‐co‐glycolic acid) (PLGA), using image based design and indirect solid freeform fabrication techniques, seeded them with bone morphogenetic protein‐7 transduced human gingival fibroblasts, and implanted them subcutaneously into mice for 4 and 8 weeks. Micro‐computed tomography data confirmed that the fabricated porous scaffolds replicated the designed architectures. Histological analysis revealed that the 50:50 PLGA scaffolds degraded but did not maintain their architecture after 4 weeks implantation. However, PLLA scaffolds maintained their architecture at both time points and showed improved bone ingrowth, which followed the internal architecture of the scaffolds. Mechanical properties of both PLLA and 50:50 PLGA scaffolds decreased but PLLA scaffolds maintained greater mechanical properties than 50:50 PLGA after implantation. The increase of mineralized tissue helped support the mechanical properties of bone tissue and scaffold constructs between 4–8 weeks. The results indicate the importance of choice of scaffold materials and computationally designed scaffolds to control tissue formation and mechanical properties for desired bone tissue regeneration. Copyright © 2011 John Wiley & Sons, Ltd. |
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Keywords: | scaffold designed architecture poly (L‐lactic acid) poly (lactic‐co‐glycolic acid) degradation bone regeneration solid freeform fabrication |
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