Tissue engineering scaffolds as three-dimensional substrates may serve as ideal templates for tissue regeneration by simulating the structure of the extracellular matrix (ECM). Many biodegradable synthetic polymers, either hydrophobic, like Poly-ε-caprolactone (PCL), or hydrophilic, like Poly(Vinyl Alcohol) (PVA), are widely used as candidate bioactive materials for fabricating tissue engineering scaffolds. However, a combination of good cytocompatibility of hydrophilic polymers with good biomechanical performance of hydrophobic polymers could be beneficial for the in vivo performance of the scaffolds. In this study, we aimed to fabricate biodegradable fibrous scaffolds by combining the properties of hydrophobic PCL with those of hydrophilic PVA and evaluate their properties in comparison with pristine PCL scaffolds. Therefore, single-layered PCL scaffolds, sequential tri-layered (PVA/PCL/PVA), and core-shell (PVA as shell and PCL as core) composite scaffolds were developed utilizing the electrospinning technique. The material structural and biomechanical properties of the electrospun scaffolds, before and after their hydrolytic degradation over a seven-month period following storage in phosphate-buffered saline (PBS) at 37 °C, were comprehensively compared. In addition, human embryonic kidney cells (HEK-293) were cultured on the scaffolds to investigate potential cell attachment, infiltration, and proliferation. The results demonstrated the long-term efficacy of core-shell biodegradable fibrous scaffolds in comparison to single-layers PCL and tri-layers PVA/PCL/PVA, not only due to its superior morphological characteristics and mechanical properties, but also due to its ability to promote homogeneous cell distribution and proliferation, without any external chemical or physical stimuli.

Graphical Abstract

中文翻译：

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用于组织工程应用的可生物降解核壳微纤维和纳米纤维支架的开发和评估

组织工程支架作为三维基质可以通过模拟细胞外基质（ECM）的结构作为组织再生的理想模板。许多可生物降解的合成聚合物，无论是疏水性的，如聚ε-己内酯（PCL），还是亲水性的，如聚（乙烯醇）（PVA），都被广泛用作制造组织工程支架的候选生物活性材料。然而，亲水性聚合物良好的细胞相容性与疏水性聚合物良好的生物力学性能的结合可能有利于支架的体内性能。在这项研究中，我们的目的是通过结合疏水性 PCL 与亲水性 PVA 的特性来制造可生物降解的纤维支架，并与原始 PCL 支架相比评估其性能。因此，利用静电纺丝技术开发了单层PCL支架、顺序三层（PVA/PCL/PVA）和核壳（PVA为壳，PCL为核）复合支架。全面比较了电纺支架在 37°C 磷酸盐缓冲盐水 (PBS) 中储存 7 个月后水解降解前后的材料结构和生物力学性能。此外，在支架上培养人胚胎肾细胞（HEK-293）以研究潜在的细胞附着、浸润和增殖。结果表明，与单层 PCL 和三层 PVA/PCL/PVA 相比，核-壳可生物降解纤维支架具有长期功效，这不仅是因为其优越的形态特征和机械性能，还因为其能够促进细胞均匀分布和增殖，无需任何外部化学或物理刺激。

图形概要