Fabrication of polycaprolactone electrospun fibers with different hierarchical structures mimicking collagen fibrils for tissue engineering scaffolds

The ability to topographically mimic the surface features of collagen fibrils is an important step in the preparation of tissue engineering scaffolds. It is important to know which kinds of surface topographies of electrospun fibers are more favorable for cell growth. In this study, fibers with three kinds of hierarchical-structured surfaces were fabricated by electrospinning to mimic collagen fibrils. By combining thermally induced phase separation (TIPS) and non-solvent induced phase separation (NIPS), polycaprolactone (PCL) fibers with a porous surface were electrospun from PCL in a chloroform (CF)/dimethyl sulfoxide (DMSO) mixed solution. In addition, two additional types of fibrous membranes, with PCL fibers being the shish and decorated by PCL kebabs on the surface, were created by two different controlled homoepitaxic crystallization methods-the solution incubation method and the solvent evaporation method. It was found that the solvent evaporation method was more effective in forming kebabs and the primary optimal processing parameters were identified. The presence of pores on the fiber surfaces contributed to a much larger surface area and a higher total volume of pores. To investigate the cellular response on such scaffolds, 3T3 fibroblast cell and human umbilical vein endothelial cell (HUVEC) assays were conducted and the results indicated that both of the nanotopographies on the surfaces of the scaffolds improved cell viability and proliferation. Furthermore, the porous surface was more beneficial for enhancing cellular responses, which suggests better biocompatibility and greater potential to mimic collagen fibrils for tissue engineering application, and especially as scaffolds for endothelial layers in blood vessels. (c) 2017 Elsevier B.V. All rights reserved.

 在地形上模仿胶原纤维表面特征的能力是制备组织工程支架中的重要步骤。首先要知道哪种电纺纤维的表面形貌更适合细胞生长。在这项研究中，通过静电纺丝来模拟胶原原纤维来制造具有三种分层结构表面的纤维。我们通过结合热诱导相分离（TIPS）和非溶剂相分离（NIPS），将具有多孔表面的聚己内酯（PCL）纤维在氯仿（CF）/二甲基亚砜（DMSO）混合溶液中由PCL静电纺丝。此外，通过两种不同的控制均方晶结晶方法（溶液孵育法和溶剂蒸发法）创建了另外两种类型的纤维膜，其中PCL纤维呈光泽，并在表面由PCL串结构装饰。发现溶剂蒸发法在形成串结构方面更有效，并且确定了最佳加工参数。纤维表面上孔的存在有助于更大的表面积和更高的孔总体积。为了研究在此类支架上的细胞反应，进行了3​​T3成纤维细胞和人脐静脉内皮细胞（HUVEC）分析，结果表明支架表面的两种纳米形貌都改善了细胞活力和增殖。此外，这种多孔表面更有利于增强细胞反应。这表明其有着很好的潜力和生物相容性来模仿胶原蛋白原纤维，应用于组织工程，尤其是作为血管内皮层的支架。 （c）2017 Elsevier B.V.保留所有权利。

Published: 2018

Journal ：APPLIED SURFACE SCIENCE

Impact Factor：6.386

Paper link: https://www.sciencedirect.com/science/article/abs/pii/S0169433217323188