Children's Hospital Affiliated to Zhengzhou University, Henan Provincial Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, 450000, China.
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065, China.
Sci Rep. 2019 Jul 2;9(1):9534. doi: 10.1038/s41598-019-46061-7.
In this study, a novel poly (vinyl alcohol) (PVA)/poly (ethylene glycol) (PEG) scaffold was carefully designed via thermal processing and subsequent supercritical fluid (SCF) foaming. Interestingly, a bimodal open-celled structure with interconnected networks was successfully created in the plasticized PVA (WPVA)/PEG scaffold. Large cells were produced from the nucleation sites generated in the PVA phase during rapid depressurization, while plenty of small pores generate in the cell walls of the big cells. The formation mechanism of this cellular structure was studied by considering the various phase morphologies and the diffusion behaviour of the carbon dioxide (CO) in individual phases. In addition, the intermolecular interactions of the WPVA/PEG blend were studied using X-ray diffraction and FTIR analysis. The results demonstrate that various types of hydrogen bonds among the hydroxyl groups on the PVA chains, PEG and water molecules are formed in the blend system. The realization of thermoplastic foaming of the PVA/PEG blend benefits from the interactions of complexation and plasticization between water and PEG molecules. The SEM images also revealed that L929 fibroblast cells were able to attach and spread on surfaces of the WPVA/PEG samples. Thus the WPVA/PEG scaffold with unique bimodal cellular structure is nontoxic and favours the attachment and proliferation of cells, making it promising for use as the candidate for tissue engineering applications.
在这项研究中，通过热加工和随后的超临界流体（SCF）发泡，精心设计了一种新型的聚乙烯醇（PVA）/聚乙二醇（PEG）支架。有趣的是，在增塑的 PVA（WPVA）/PEG 支架中成功地创建了具有互连网络的双峰开孔结构。大孔是由 PVA 相中在快速减压过程中产生的成核点产生的，而大量的小孔则产生在大孔的细胞壁中。通过考虑各相的不同相形态和二氧化碳（CO）在各相中的扩散行为，研究了这种蜂窝结构的形成机理。此外，还使用 X 射线衍射和 FTIR 分析研究了 WPVA/PEG 共混物的分子间相互作用。结果表明，在共混体系中形成了 PVA 链上的羟基、PEG 和水分子之间的各种类型的氢键。PVA/PEG 共混物的热塑性发泡得益于水和 PEG 分子之间的络合和增塑相互作用。SEM 图像还表明，L929 成纤维细胞能够附着并在 WPVA/PEG 样品表面上扩展。因此，具有独特双峰蜂窝结构的 WPVA/PEG 支架是无毒的，有利于细胞的附着和增殖，有望成为组织工程应用的候选材料。
