Bakhtiari Hamed, Nouri Alireza, Khakbiz Mehrdad, Tolouei-Rad Majid
Center for Advanced Materials and Manufacturing (CAMM), School of Engineering, Edith Cowan University, Joondalup, WA 6027, Australia.
School of Engineering, RMIT University, Melbourne, VIC 3001, Australia.
Acta Biomater. 2023 Dec;172:16-37. doi: 10.1016/j.actbio.2023.09.048. Epub 2023 Oct 4.
Bone scaffolds play a crucial role in bone tissue engineering by providing mechanical support for the growth of new tissue while enduring static and fatigue loads. Although polymers possess favourable characteristics such as adjustable degradation rate, tissue-compatible stiffness, ease of fabrication, and low toxicity, their relatively low mechanical strength has limited their use in load-bearing applications. While numerous studies have focused on assessing the static strength of polymeric scaffolds, little research has been conducted on their fatigue properties. The current review presents a comprehensive study on the fatigue behaviour of polymeric bone scaffolds. The fatigue failure in polymeric scaffolds is discussed and the impact of material properties, topological features, loading conditions, and environmental factors are also examined. The present review also provides insight into the fatigue damage evolution within polymeric scaffolds, drawing comparisons to the behaviour observed in natural bone. Additionally, the effect of polymer microstructure, incorporating reinforcing materials, the introduction of topological features, and hydrodynamic/corrosive impact of body fluids in the fatigue life of scaffolds are discussed. Understanding these parameters is crucial for enhancing the fatigue resistance of polymeric scaffolds and holds promise for expanding their application in clinical settings as structural biomaterials. STATEMENT OF SIGNIFICANCE: Polymers have promising advantages for bone tissue engineering, including adjustable degradation rates, compatibility with native bone stiffness, ease of fabrication, and low toxicity. However, their limited mechanical strength has hindered their use in load-bearing scaffolds for clinical applications. While prior studies have addressed static behaviour of polymeric scaffolds, a comprehensive review of their fatigue performance is lacking. This review explores this gap, addressing fatigue characteristics, failure mechanisms, and the influence of parameters like material properties, topological features, loading conditions, and environmental factors. It also examines microstructure, reinforcement materials, pore architectures, body fluids, and tissue ingrowth effects on fatigue behaviour. A significant emphasis is placed on understanding fatigue damage progression in polymeric scaffolds, comparing it to natural bone behaviour.
骨支架在骨组织工程中起着至关重要的作用，它为新组织的生长提供机械支撑，同时承受静态和疲劳载荷。尽管聚合物具有诸如可调节的降解速率、与组织相容的刚度、易于制造和低毒性等有利特性，但其相对较低的机械强度限制了它们在承重应用中的使用。虽然众多研究集中于评估聚合物支架的静态强度，但对其疲劳性能的研究却很少。本综述对聚合物骨支架的疲劳行为进行了全面研究。讨论了聚合物支架中的疲劳失效，并研究了材料特性、拓扑特征、加载条件和环境因素的影响。本综述还深入探讨了聚合物支架内的疲劳损伤演变，并与天然骨中观察到的行为进行了比较。此外，还讨论了聚合物微观结构、加入增强材料、引入拓扑特征以及体液的流体动力/腐蚀作用对支架疲劳寿命的影响。了解这些参数对于提高聚合物支架的抗疲劳性至关重要，并有望扩大其在临床环境中作为结构生物材料的应用。重要性声明：聚合物在骨组织工程中具有有前景的优势，包括可调节的降解速率、与天然骨刚度的相容性、易于制造和低毒性。然而，其有限的机械强度阻碍了它们在临床应用的承重支架中的使用。虽然先前的研究已经探讨了聚合物支架的静态行为，但缺乏对其疲劳性能的全面综述。本综述探讨了这一差距，阐述了疲劳特性、失效机制以及材料特性、拓扑特征、加载条件和环境因素等参数的影响。它还研究了微观结构、增强材料、孔隙结构、体液和组织长入对疲劳行为的影响。重点在于理解聚合物支架中的疲劳损伤进展，并将其与天然骨行为进行比较。
