Den Buijs Jorn Op, Lu Lichun, Jorgensen Steven M, Dragomir-Daescu Dan, Yaszemski Michael J, Ritman Erik L
Physiological Imaging Research Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Tissue Eng Part A. 2009 Aug;15(8):1989-99. doi: 10.1089/ten.tea.2008.0382.
The objective of this study was to investigate the influence of pore geometry on the transport rate and depth after repetitive mechanical deformation of porous scaffolds for tissue engineering applications. Flexible cubic imaging phantoms with pores in the shape of a circular cylinder, elliptic cylinder, and spheroid were fabricated from a biodegradable polymer blend using a combined 3D printing and injection molding technique. The specimens were immersed in fluid and loaded with a solution of a radiopaque solute. The solute distribution was quantified by recording 20 microm pixel-resolution images in an X-ray microimaging scanner at selected time points after intervals of dynamic straining with a mean strain of 8.6+/-1.6% at 1.0 Hz. The results show that application of cyclic strain significantly increases the rate and depth of solute transport, as compared to diffusive transport alone, for all pore shapes. In addition, pore shape, pore size, and the orientation of the pore cross-sectional asymmetry with respect to the direction of strain greatly influence solute transport. Thus, pore geometry can be tailored to increase transport rates and depths in cyclically deformed scaffolds, which is of utmost importance when thick, metabolically functional tissues are to be engineered.
本研究的目的是调查孔隙几何形状对用于组织工程应用的多孔支架在反复机械变形后的传输速率和深度的影响。使用3D打印和注塑成型相结合的技术，由可生物降解的聚合物共混物制造出具有圆柱、椭圆圆柱和球体形状孔隙的柔性立方体成像体模。将标本浸入流体中，并用不透射线溶质的溶液加载。在以1.0Hz的频率施加平均应变为8.6±1.6%的动态应变间隔后的选定时间点，通过在X射线微成像扫描仪中记录20微米像素分辨率的图像来量化溶质分布。结果表明，与仅扩散传输相比，对于所有孔隙形状，循环应变的施加显著提高了溶质传输的速率和深度。此外，孔隙形状、孔径以及孔隙横截面不对称相对于应变方向的取向极大地影响溶质传输。因此，可以调整孔隙几何形状以提高在周期性变形支架中的传输速率和深度，这在构建厚的、具有代谢功能的组织时至关重要。
