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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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Local shear stress histogram distributions at different time points with the vertical axis showing the frequency density within a given shear range (log-based bin range). (a,b) At time point 16.7 h, shear distributions at four different inflow velocities in the regular (a) and 30% randomized (b) structures. (c,d) At inflow velocity 0.2 mm/s, shear distributions at four different time points in the regular (c) and 30% randomized (d) structures. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]
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fig05: Local shear stress histogram distributions at different time points with the vertical axis showing the frequency density within a given shear range (log-based bin range). (a,b) At time point 16.7 h, shear distributions at four different inflow velocities in the regular (a) and 30% randomized (b) structures. (c,d) At inflow velocity 0.2 mm/s, shear distributions at four different time points in the regular (c) and 30% randomized (d) structures. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]

Mentions: The distributions of local shear stress throughout the regular and randomized implants are shown in Figure 5 as fluid volume normalized histograms. Shear stress values corresponding to all the interfacial cells are counted and normalized by the total fluid volume. Five key parameters are extracted in Table 2: the mean, standard deviation of shear stress and the mode, skew and kurtosis of the distribution at both early and final growth stages. The strong influence of inflow velocity and strut structure on local shear stress is clearly shown. In the regular structure, more local cells have higher shear stress with the increase of inlet velocity. This trend is also shown for the randomized structure. However, in the 30% randomized structure, both the shifts in modal values of the shear stress from 2.6 to 71.1 mPa at early stage and 5.8 to 71.1 mPa at final stage reveal greater ranges than those in the regular structure [(Figure 5(b)].


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)

Local shear stress histogram distributions at different time points with the vertical axis showing the frequency density within a given shear range (log-based bin range). (a,b) At time point 16.7 h, shear distributions at four different inflow velocities in the regular (a) and 30% randomized (b) structures. (c,d) At inflow velocity 0.2 mm/s, shear distributions at four different time points in the regular (c) and 30% randomized (d) structures. [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

fig05: Local shear stress histogram distributions at different time points with the vertical axis showing the frequency density within a given shear range (log-based bin range). (a,b) At time point 16.7 h, shear distributions at four different inflow velocities in the regular (a) and 30% randomized (b) structures. (c,d) At inflow velocity 0.2 mm/s, shear distributions at four different time points in the regular (c) and 30% randomized (d) structures. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]
Mentions: The distributions of local shear stress throughout the regular and randomized implants are shown in Figure 5 as fluid volume normalized histograms. Shear stress values corresponding to all the interfacial cells are counted and normalized by the total fluid volume. Five key parameters are extracted in Table 2: the mean, standard deviation of shear stress and the mode, skew and kurtosis of the distribution at both early and final growth stages. The strong influence of inflow velocity and strut structure on local shear stress is clearly shown. In the regular structure, more local cells have higher shear stress with the increase of inlet velocity. This trend is also shown for the randomized structure. However, in the 30% randomized structure, both the shifts in modal values of the shear stress from 2.6 to 71.1 mPa at early stage and 5.8 to 71.1 mPa at final stage reveal greater ranges than those in the regular structure [(Figure 5(b)].

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