TY - JOUR
T1 - Cyclic deformation-induced solute transport in tissue scaffolds with computer designed, interconnected, pore networks
T2 - Experiments and simulations
AU - Op Den Buijs, Jorn
AU - Dragomir-Daescu, Dan
AU - Ritman, Erik L.
N1 - Funding Information:
This work was supported in part by the Mayo Graduate School and NIH grant EB000305. The authors thank the Division of Engineering of Mayo Clinic for hardware and software support to run the numerical simulations, and Ms. Geraldine K. Bernard for help with injection mold printing.
PY - 2009/8
Y1 - 2009/8
N2 - Nutrient supply and waste removal in porous tissue engineering scaffolds decrease from the periphery to the center, leading to limited depth of ingrowth of new tissue into the scaffold. However, as many tissues experience cyclic physiological strains, this may provide a mechanism to enhance solute transport in vivo before vascularization of the scaffold. The hypothesis of this study was that pore cross-sectional geometry and interconnectivity are of major importance for the effectiveness of cyclic deformation-induced solute transport. Transparent elastic polyurethane scaffolds, with computer-programmed design of pore networks in the form of interconnected channels, were fabricated using a 3D printing and injection molding technique. The scaffold pores were loaded with a colored tracer for optical contrast, cyclically compressed with deformations of 10 and 15% of the original undeformed height at 1.0 Hz. Digital imaging was used to quantify the spatial distribution of the tracer concentration within the pores. Numerical simulations of a fluid-structure interaction model of deformation-induced solute transport were compared to the experimental data. The results of experiments and modeling agreed well and showed that pore interconnectivity heavily influences deformation-induced solute transport. Pore cross-sectional geometry appears to be of less relative importance in interconnected pore networks. Validated computer models of solute transport can be used to design optimal scaffold pore geometries that will enhance the convective transport of nutrients inside the scaffold and the removal of waste, thus improving the cell survivability deep inside the scaffold.
AB - Nutrient supply and waste removal in porous tissue engineering scaffolds decrease from the periphery to the center, leading to limited depth of ingrowth of new tissue into the scaffold. However, as many tissues experience cyclic physiological strains, this may provide a mechanism to enhance solute transport in vivo before vascularization of the scaffold. The hypothesis of this study was that pore cross-sectional geometry and interconnectivity are of major importance for the effectiveness of cyclic deformation-induced solute transport. Transparent elastic polyurethane scaffolds, with computer-programmed design of pore networks in the form of interconnected channels, were fabricated using a 3D printing and injection molding technique. The scaffold pores were loaded with a colored tracer for optical contrast, cyclically compressed with deformations of 10 and 15% of the original undeformed height at 1.0 Hz. Digital imaging was used to quantify the spatial distribution of the tracer concentration within the pores. Numerical simulations of a fluid-structure interaction model of deformation-induced solute transport were compared to the experimental data. The results of experiments and modeling agreed well and showed that pore interconnectivity heavily influences deformation-induced solute transport. Pore cross-sectional geometry appears to be of less relative importance in interconnected pore networks. Validated computer models of solute transport can be used to design optimal scaffold pore geometries that will enhance the convective transport of nutrients inside the scaffold and the removal of waste, thus improving the cell survivability deep inside the scaffold.
KW - Computational modeling
KW - Cyclic strain
KW - Imaging
KW - Solid freeform fabrication
KW - Tissue engineering
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U2 - 10.1007/s10439-009-9712-3
DO - 10.1007/s10439-009-9712-3
M3 - Article
C2 - 19466547
AN - SCOPUS:70349579970
SN - 0090-6964
VL - 37
SP - 1601
EP - 1612
JO - Annals of Biomedical Engineering
JF - Annals of Biomedical Engineering
IS - 8
ER -