Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE 10044 Stockholm, Sweden.
Tissue Engineering Group, Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Årstadveien 19, 5009 Bergen, Norway.
Mater Sci Eng C Mater Biol Appl. 2021 May;124:112020. doi: 10.1016/j.msec.2021.112020. Epub 2021 Mar 18.
Aliphatic polyesters are the synthetic polymers most commonly used in the development of resorbable medical implants/devices. Various three-dimensional (3D) scaffolds have been fabricated from these polymers and used in adipose tissue engineering. However, their systematic evaluation altogether lacks, which makes it difficult to select a suitable degradable polymer to design 3D resorbable implants and/or devices able to effectively mimic the properties of adipose tissue. Additionally, the impact of sterilization methods on the medical devices, if any, must be taken into account. We evaluate and compare five different medical-grade resorbable polyesters with l-lactide content ranging from 50 to 100 mol% and exhibiting different physiochemical properties depending on the comonomer (d-lactide, ε-caprolactone, glycolide, and trimethylene carbonate). The salt-leaching technique was used to prepare 3D microporous scaffolds. A comprehensive assessment of physical, chemical, and mechanical properties of the scaffolds was carried out in PBS at 37 °C. The cell-material interactions and the ability of the scaffolds to promote adipogenesis of human adipose tissue-derived stem cells were assessed in vitro. The diverse physical and mechanical properties of the scaffolds, due to the different composition of the copolymers, influenced human adipose tissue-derived stem cells proliferation and differentiation. Scaffolds made from polymers which were above their glass transition temperature and with low degree of crystallinity showed better proliferation and adipogenic differentiation of stem cells. The effect of sterilization techniques (electron beam and ethylene oxide) on the polymer properties was also evaluated. Results showed that scaffolds sterilized with the ethylene oxide method better retained their physical and chemical properties. Overall, the presented research provides (i) a detailed understanding to select a degradable polymer that has relevant properties to augment adipose tissue regeneration and can be further used to fabricate medical devices/implants; (ii) directions to prefer a sterilization method that does not change polymer properties.
脂肪族聚酯是最常用于开发可吸收医疗植入物/器械的合成聚合物。已经从这些聚合物中制造了各种三维（3D）支架，并将其用于脂肪组织工程中。然而，它们的系统评估缺乏，这使得难以选择合适的可降解聚合物来设计 3D 可吸收植入物和/或设备，以有效地模拟脂肪组织的特性。此外，如果有的话，还必须考虑灭菌方法对医疗器械的影响。我们评估并比较了五种不同的医用级可吸收聚酯，其 l-丙交酯含量在 50 至 100 mol%之间，并且根据共聚单体（d-丙交酯、ε-己内酯、乙交酯和三亚甲基碳酸酯）表现出不同的物理化学性质。盐浸出技术用于制备 3D 微孔支架。在 37°C 的 PBS 中对支架的物理、化学和机械性能进行了全面评估。在体外评估了细胞-材料相互作用以及支架促进人脂肪组织来源干细胞成脂分化的能力。由于共聚物的不同组成，支架的不同物理和机械性能影响了人脂肪组织来源干细胞的增殖和分化。由高于玻璃化转变温度和低结晶度的聚合物制成的支架显示出更好的干细胞增殖和成脂分化能力。还评估了灭菌技术（电子束和环氧乙烷）对聚合物性能的影响。结果表明，用环氧乙烷方法灭菌的支架更好地保留了其物理和化学性质。总的来说，所提出的研究提供了（i）选择具有相关性质以增强脂肪组织再生的可降解聚合物的详细了解，并可进一步用于制造医疗器械/植入物；（ii）指导选择不会改变聚合物性质的灭菌方法。
