School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, New South Wales 2006, Australia.
Biomaterials. 2011 Aug;32(22):5003-14. doi: 10.1016/j.biomaterials.2011.03.064. Epub 2011 May 2.
Biodegradable scaffolds play a critical role in therapeutic tissue engineering, in which the matrix degradation and tissue ingrowth are of particular importance for determining the ongoing performance of tissue-scaffold system during regenerative process. This paper aims to explore the mechanobiological process within biodegradable scaffolds, where the representative volume element (RVE) is extracted from periodic scaffold micro-architectures as a base-cell design model. The degradation of scaffold matrix is modeled in terms of a stochastic hydrolysis process enhanced by diffusion-controlled autocatalysis; and the tissue ingrowth is modeled through the mechano-regulatory theory. By using the finite element based homogenization technique and topology optimization approach, the effective properties of various periodic scaffold structures are obtained. To explore the effect of scaffold design on the mechanobiological evolutions of tissue-scaffold systems, different scaffold architectures are considered for polymer degradation and tissue regeneration. It is found that the different tissues can grow into the degraded voids inside the polymer matrix. It is demonstrated that the design of scaffold architecture has a considerable impact on the tissue regeneration outcome, which exhibits the importance of implementing different criteria in scaffold micro-structural design, before being fabricated via rapid prototyping technique, e.g. solid free-form fabrication (SFF). This study models such an interactive process of scaffold degradation and tissue growth, thereby providing some new insights into design of biodegradable scaffold micro-architecture for tissue engineering.
可生物降解支架在治疗性组织工程中起着至关重要的作用，其中基质降解和组织内生长对于确定组织-支架系统在再生过程中的持续性能尤为重要。本文旨在探索可生物降解支架内的机械生物学过程，其中从周期性支架微观结构中提取代表性体积元 (RVE) 作为基本细胞设计模型。支架基质的降解通过扩散控制自催化增强的随机水解过程进行建模；组织内生长通过机械调节理论进行建模。通过使用基于有限元的均匀化技术和拓扑优化方法，获得了各种周期性支架结构的有效性能。为了探索支架设计对组织-支架系统机械生物学演化的影响，考虑了不同的支架结构用于聚合物降解和组织再生。结果发现，不同的组织可以生长到聚合物基质中的降解空隙中。结果表明，支架结构的设计对组织再生结果有很大的影响，这表明在通过快速原型制造技术（例如，自由形式制造（SFF））制造之前，在支架微观结构设计中实施不同标准非常重要。本研究模拟了支架降解和组织生长的这种相互作用过程，从而为组织工程中的可生物降解支架微结构设计提供了一些新的见解。
