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Modeling of time dependent localized flow shear stress and its impact on cellular growth within additive manufactured titanium implants.

Zhang Z, Yuan L, Lee PD, Jones E, Jones JR - J. Biomed. Mater. Res. Part B Appl. Biomater. (2014)

Bottom Line: The model's effectiveness is demonstrated for two additive manufactured (AM) titanium scaffold architectures.The results demonstrate that there is a complex interaction of flow rate and strut architecture, resulting in partially randomized structures having a preferential impact on stimulating cell migration in 3D porous structures for higher flow rates.This novel result demonstrates the potential new insights that can be gained via the modeling tool developed, and how the model can be used to perform what-if simulations to design AM structures to specific functional requirements.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials, Imperial College London, London, SW7 2AZ, UK.

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(a) Comparative plot of cellular growth vs. time between the regular and 30% randomized structures at different inflow velocities. Insets: I showing the blockage of the channels in the regular structure at later time stage; II showing the concentration of shear stress in the randomized structure, where indicates more growth at later stages after 70 h. (b) Effect of maximum shear constraint on bone ingrowth at inflow velocity of 0.2 mm/s in the regular and 30% randomized structures. (i,ii) showing the final growth at 120 h without capping the shear stress. (iii,iv) showing zoomed in features of cellular growth (colored red). (v,vi) showing the final growth at 120 h with the shear constraint. Contour colored by shear stress. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]
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fig06: (a) Comparative plot of cellular growth vs. time between the regular and 30% randomized structures at different inflow velocities. Insets: I showing the blockage of the channels in the regular structure at later time stage; II showing the concentration of shear stress in the randomized structure, where indicates more growth at later stages after 70 h. (b) Effect of maximum shear constraint on bone ingrowth at inflow velocity of 0.2 mm/s in the regular and 30% randomized structures. (i,ii) showing the final growth at 120 h without capping the shear stress. (iii,iv) showing zoomed in features of cellular growth (colored red). (v,vi) showing the final growth at 120 h with the shear constraint. Contour colored by shear stress. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]

Mentions: A comparative plot of volume fraction occupied by cells over time in the two structures is shown in Figure 6(a). A tenfold increase in inflow velocities causes a nine times increase in cellular growth (1.9–17.5%) in the regular structure after 120 h while in the randomized structure, cellular growth is initially similar for all inflow velocities, but after 60 h, it shows a faster migration with a 11.5 times increase in bone volume (1.7–19.5%).


Modeling of time dependent localized flow shear stress and its impact on cellular growth within additive manufactured titanium implants.

Zhang Z, Yuan L, Lee PD, Jones E, Jones JR - J. Biomed. Mater. Res. Part B Appl. Biomater. (2014)

(a) Comparative plot of cellular growth vs. time between the regular and 30% randomized structures at different inflow velocities. Insets: I showing the blockage of the channels in the regular structure at later time stage; II showing the concentration of shear stress in the randomized structure, where indicates more growth at later stages after 70 h. (b) Effect of maximum shear constraint on bone ingrowth at inflow velocity of 0.2 mm/s in the regular and 30% randomized structures. (i,ii) showing the final growth at 120 h without capping the shear stress. (iii,iv) showing zoomed in features of cellular growth (colored red). (v,vi) showing the final growth at 120 h with the shear constraint. Contour colored by shear stress. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4288932&req=5

fig06: (a) Comparative plot of cellular growth vs. time between the regular and 30% randomized structures at different inflow velocities. Insets: I showing the blockage of the channels in the regular structure at later time stage; II showing the concentration of shear stress in the randomized structure, where indicates more growth at later stages after 70 h. (b) Effect of maximum shear constraint on bone ingrowth at inflow velocity of 0.2 mm/s in the regular and 30% randomized structures. (i,ii) showing the final growth at 120 h without capping the shear stress. (iii,iv) showing zoomed in features of cellular growth (colored red). (v,vi) showing the final growth at 120 h with the shear constraint. Contour colored by shear stress. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]
Mentions: A comparative plot of volume fraction occupied by cells over time in the two structures is shown in Figure 6(a). A tenfold increase in inflow velocities causes a nine times increase in cellular growth (1.9–17.5%) in the regular structure after 120 h while in the randomized structure, cellular growth is initially similar for all inflow velocities, but after 60 h, it shows a faster migration with a 11.5 times increase in bone volume (1.7–19.5%).

Bottom Line: The model's effectiveness is demonstrated for two additive manufactured (AM) titanium scaffold architectures.The results demonstrate that there is a complex interaction of flow rate and strut architecture, resulting in partially randomized structures having a preferential impact on stimulating cell migration in 3D porous structures for higher flow rates.This novel result demonstrates the potential new insights that can be gained via the modeling tool developed, and how the model can be used to perform what-if simulations to design AM structures to specific functional requirements.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials, Imperial College London, London, SW7 2AZ, UK.

Show MeSH
Related in: MedlinePlus