Centro de Investigação de Materiais, Institute for Nanostructures, Nanomodelling and Nanofabrication, CENIMAT-I3N, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Centro de Investigação de Materiais, Institute for Nanostructures, Nanomodelling and Nanofabrication, CENIMAT-I3N, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Mater Sci Eng C Mater Biol Appl. 2019 Oct;103:109819. doi: 10.1016/j.msec.2019.109819. Epub 2019 May 30.
The composition and architecture of a scaffold determine its supportive role in tissue regeneration. In this work, we demonstrate the feasibility of obtaining a porous electrospun fibrous structure from biodegradable polyurethanes (Pus) synthesized using polycaprolactone-diol as soft segment and, as chain extenders, chitosan (CS) and/or dimethylol propionic acid. Fourier transform infrared spectroscopy and proton nuclear magnetic resonance confirmed the syntheses. Fibre mats' properties were analysed and compared with those of solvent cast films. Scanning electron microscopy images of the electrospun scaffolds revealed fibres with diameters around 1 μm. From tensile tests, we found that Young's modulus increases with CS content and is higher for films (2.5 MPa to 6.5 MPa) than for the corresponding fibre mats (0.8 MPa to 3.2 MPa). The use of CS as the only chain extender improves recovery ratio and resilience. From X-ray diffraction, a higher crystalline degree was identified in fibre mats than in the corresponding films. Films' wettability was enhanced by the presence of CS as shown by the decrease of water contact angle. X-ray photoelectron spectroscopy revealed that while ester groups are predominant at the films' surface, ester and urethanes are present in similar concentrations at fibres' surface, favouring the interaction with water molecules. Both films and fibres undergo hydrolytic degradation. In vitro evaluation was performed with human dermal fibroblasts. No PU sample revealed cytotoxicity. Cells adhered to fibre mats better than to films and proliferation was observed only for samples of CS-containing PUs. Results suggest that electrospun fibres of CS-based polyurethanes are good candidate scaffolds for soft tissue engineering.
支架的组成和结构决定了其在组织再生中的支撑作用。在这项工作中，我们展示了从使用聚己内酯二醇作为软段和作为扩链剂的壳聚糖（CS）和/或二羟甲基丙酸合成的可生物降解聚碳酸酯制备多孔电纺纤维结构的可行性。傅里叶变换红外光谱和质子核磁共振证实了合成。分析了纤维垫的性能，并与溶剂浇铸膜的性能进行了比较。电纺支架的扫描电子显微镜图像显示纤维直径约为 1μm。从拉伸试验中，我们发现 CS 含量的增加会提高杨氏模量，并且对于薄膜（2.5 MPa 至 6.5 MPa）比相应的纤维垫（0.8 MPa 至 3.2 MPa）更高。仅使用 CS 作为扩链剂可提高恢复率和回弹性。从 X 射线衍射中可以看出，纤维垫的结晶度高于相应的薄膜。如接触角的降低所示，CS 的存在提高了薄膜的润湿性。X 射线光电子能谱表明，尽管在薄膜表面上主要存在酯基，但在纤维表面上存在酯基和氨酯，这有利于与水分子的相互作用。薄膜和纤维都经历水解降解。用人真皮成纤维细胞进行了体外评价。没有 PU 样品显示出细胞毒性。细胞在纤维垫上的黏附性优于在薄膜上的黏附性，并且仅在含有 CS 的 PU 样品中观察到增殖。结果表明，基于 CS 的聚碳酸酯的电纺纤维是软组织工程的良好候选支架。
