Porous polymeric scaffolds are used in tissue engineering to maintain or replace damaged biological tissues. Once embedded in body, they are involved into different physical and biological processes, among which their degradation and dissolution of their material can be singled out as one of the most important ones. Degradation parameters depend mostly on the properties of both the material and surrounding native tissues, which can substantially alter the original mechanical parameters of the scaffolds. The aim of this study is to examine the change in the effective mechanical properties of functionally graded additively manufactured polylactide scaffolds with a linear porosity gradient and morphology based on triply periodic minimal surfaces during simultaneous degradation and compressive loading. Two main types of scaffold-degradation processes, bulk and surface erosions are simulated with two suggested modelling methods. The fundamental differences in the proposed approaches are identified and the influence of different types of scaffold morphology on the change in effective elastic properties is evaluated. The results of this study can be useful for design of optimal scaffolds taking into account the effect of the degradation process on their structural integrity.

中文翻译：

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聚合物支架降解对机械性能的影响：表面侵蚀与整体侵蚀

多孔聚合物支架用于组织工程中以维持或替换受损的生物组织。一旦嵌入体内，它们就会参与不同的物理和生物过程，其中材料的降解和溶解可以被选为最重要的过程之一。降解参数主要取决于材料和周围天然组织的特性，这可以显着改变支架的原始机械参数。本研究的目的是检查功能梯度增材制造的聚丙交酯支架在同时降解和压缩加载过程中的有效机械性能的变化，该支架具有基于三周期最小表面的线性孔隙率梯度和形态。使用两种建议的建模方法模拟两种主要类型的支架降解过程，即整体侵蚀和表面侵蚀。确定了所提出方法的根本差异，并评估了不同类型支架形态对有效弹性性能变化的影响。考虑到降解过程对其结构完整性的影响，这项研究的结果可用于设计最佳支架。