Elenskaya Nataliya, Vindokurov Ilia, Sadyrin Evgeniy, Nikolaev Andrey, Tashkinov Mikhail
Laboratory of Mechanics of Biocompatible Materials and Devices, Perm National Research Polytechnic University, 614990 Perm, Russia.
Laboratory for Mechanics of Biomaterials, Don State Technical University, 344000 Rostov-on-Don, Russia.
Polymers (Basel). 2024 Dec 12;16(24):3474. doi: 10.3390/polym16243474.
Bone transplantation ranks second worldwide among tissue prosthesis surgeries. Currently, one of the most promising approaches is regenerative medicine, which involves tissue engineering based on polymer scaffolds with biodegradable properties. Once implanted, scaffolds interact directly with the surrounding tissues and in a fairly aggressive environment, which causes biodegradation of the scaffold material. The aim of this work is to experimentally investigate the changes in the effective mechanical properties of polylactide scaffolds manufactured using additive technologies. The mechanism and the rate of the degradation process depend on the chosen material, contact area, microstructural features, and overall architecture of sample. To assess the influence of each of these factors, solid samples with different dimensions and layers orientation as well as prototypes of functionally graded scaffolds were studied. The research methodology includes the assessment of changes in the mechanical properties of the samples, as well as their structural characteristics. Changes in the mechanical properties were measured in compression tests. Microcomputed tomography (micro-CT) studies were conducted to evaluate changes in the microstructure of scaffold prototypes. Changes caused by surface erosion and their impact on degradation were assessed using morphometric analysis. Nonlinear changes in mechanical properties were observed for both solid samples and lattice graded scaffold prototypes depending on the duration of immersion in NaCl solution and exposure to different temperatures. At the temperature of 37 °C, the decrease in the elastic modulus of solid specimens was no more than 16%, while for the lattice scaffolds, it was only 4%. For expedited degradation during a higher temperature of 45 °C, these ratios were 47% and 16%, respectively. The decrease in compressive strength was no more than 32% for solid specimens and 17% for scaffolds. The results of this study may be useful for the development of optimal scaffolds considering the impact of the degradation process on their structural integrity.
骨移植手术在全球组织假体手术中排名第二。目前，最有前景的方法之一是再生医学，它涉及基于具有生物可降解特性的聚合物支架的组织工程。一旦植入，支架会在相当恶劣的环境中直接与周围组织相互作用，这会导致支架材料发生生物降解。这项工作的目的是通过实验研究使用增材制造技术制造的聚乳酸支架有效力学性能的变化。降解过程的机制和速率取决于所选材料、接触面积、微观结构特征以及样品的整体结构。为了评估这些因素各自的影响，研究了具有不同尺寸和层取向的实心样品以及功能梯度支架的原型。研究方法包括评估样品力学性能的变化及其结构特征。在压缩试验中测量力学性能的变化。进行微计算机断层扫描（micro-CT）研究以评估支架原型微观结构的变化。使用形态计量分析评估由表面侵蚀引起的变化及其对降解的影响。根据在NaCl溶液中的浸泡时间和暴露于不同温度，实心样品和晶格梯度支架原型的力学性能均出现非线性变化。在37°C温度下，实心样品的弹性模量降低不超过16%，而对于晶格支架，仅为4%。在45°C的较高温度下加速降解时，这些比例分别为47%和16%。实心样品的抗压强度降低不超过32%，支架的抗压强度降低不超过17%。考虑到降解过程对其结构完整性的影响，本研究结果可能有助于开发最佳支架。
