Bioresorbable scaffolds for bone tissue engineering: optimal design, fabrication, mechanical testing and scale-size
Pedro G Coelho1, Scott J Hollister2, Colleen L Flanagan2
1UNIDEMI, Department of Mechanical and Industrial Engineering, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Medical Engineering & Physics
|February 3, 2015
Summary
Topology optimization and additive manufacturing create complex bone scaffolds. This study reveals manufacturing processes introduce discrepancies, but numerical and experimental results show good correlation for reproducible scaffold design.
Area of Science:
- Biomaterials Engineering
- Tissue Engineering
- Computational Mechanics
Background:
- Bone scaffolds require balancing biological and mechanical properties for tissue regeneration.
- Topology optimization and additive manufacturing offer pathways to engineer complex scaffold designs.
- Bridging the gap between scaffold design and reproducible manufacturing remains a significant research challenge.
Purpose of the Study:
- To investigate the impact of the design-to-manufacture chain on the reproducibility of complex scaffold characteristics.
- To analyze scale size effects in finite periodic scaffolds compared to homogenization predictions.
- To evaluate discrepancies between computational models and experimental mechanical properties of manufactured scaffolds.
Main Methods:
- Utilized topology optimization (homogenization approach) for scaffold design.
- Employed additive manufacturing for prototype fabrication.
- Performed mechanical testing on manufactured scaffolds.
- Investigated scale size effects considering finite periodicity of unit-cells.
- Compared experimental results with numerical simulations.
Main Results:
- Limited unit-cells (3-5) in scaffolds showed scale effects below 10% discrepancy.
- Higher discrepancies between simulations and experiments were attributed to manufacturing variations (feature shape/size, micro-porosities).
- Strong regression correlations (R(2) > 0.85) were observed between numerical and experimental data for most designs.
Conclusions:
- The design-to-manufacture process introduces variations affecting scaffold reproducibility.
- Despite manufacturing challenges, topology-optimized scaffolds demonstrate predictable mechanical behavior with good correlation between simulation and experiment.
- Further refinement of manufacturing processes is crucial for precise replication of complex scaffold designs.
