Background: Researchers are trying to study the mechanism of neural stem cells (NSCs) differentiation to oligodendrocyte-like cells (OLCs) as well as to enhance the selective differentiation of NSCs to oligodendrocytes. However, the limitation in nerve tissue accessibility to isolate the NSCs as well as their differentiation toward oligodendrocytes is still challenging.
Purpose: In the present study, a hybrid polycaprolactone (PCL)-gelatin nanofiber scaffold mimicking the native extracellular matrix and axon morphology to direct the differentiation of bone marrow-derived NSCs to OLCs was introduced.
Materials and Methods: In order to achieve a sustained release of T3, this factor was encapsulated within chitosan nanoparticles and chitosan-loaded T3 was incorporated within PCL nanofibers. Polyaniline graphene (PAG) nanocomposite was incorporated within gelatin nanofibers to endow the scaffold with conductive properties, which resemble the conductive behavior of axons. Biodegradation, water contact angle measurements, and scanning electron microscopy (SEM) observations as well as conductivity tests were used to evaluate the properties of the prepared scaffold. The concentration of PAG and T3-loaded chitosan NPs in nanofibers were optimized by examining the proliferation of cultured bone marrow-derived mesenchymal stem cells (BMSCs) on the scaffolds. The differentiation of BMSCs-derived NSCs cultured on the fabricated scaffolds into OLCs was analyzed by evaluating the expression of oligodendrocyte markers using immunofluorescence (ICC), RT-PCR and flowcytometric assays.
Results: Incorporating 2% PAG proved to have superior cell support and proliferation while guaranteeing electrical conductivity of 10.8 × 10^{− 5} S/cm. Moreover, the scaffold containing 2% of T3-loaded chitosan NPs was considered to be the most biocompatible samples. Result of ICC, RT-PCR and flow cytometry showed high expression of O4, Olig2, platelet-derived growth factor receptor-alpha (PDGFR-α), O1, myelin/oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP) high expressed but low expression of glial fibrillary acidic protein (GFAP).
Conclusion: Considering surface topography, biocompatibility, electrical conductivity and gene expression, the hybrid PCL/gelatin scaffold with the controlled release of T3 may be considered as a promising candidate to be used as an in vitro model to study patient-derived oligodendrocytes by isolating patient’s BMSCs in pathological conditions such as diseases or injuries. Moreover, the resulted oligodendrocytes can be used as a desirable source for transplanting in patients.



中文翻译：

---

用于将骨髓来源的神经干细胞分化为少突胶质细胞样细胞的仿生纳米纤维支架：设计、制造和表征。

背景：研究人员正试图研究神经干细胞 (NSCs) 分化为少突胶质细胞样细胞 (OLCs) 的机制，以及增强 NSCs 向少突胶质细胞的选择性分化。然而，神经组织可及性的限制以分离 NSC 以及它们向少突胶质细胞的分化仍然具有挑战性。
目的：在本研究中，引入了一种混合聚己内酯 (PCL)-明胶纳米纤维支架，该支架模拟天然细胞外基质和轴突形态，以指导骨髓来源的 NSC 向 OLC 的分化。
材料和方法：为了实现 T3 的持续释放，将该因子封装在壳聚糖纳米颗粒中，并将负载壳聚糖的 T3 掺入 PCL 纳米纤维中。聚苯胺石墨烯 (PAG) 纳米复合材料掺入明胶纳米纤维中，赋予支架导电性能，类似于轴突的导电行为。生物降解、水接触角测量、扫描电子显微镜 (SEM) 观察以及电导率测试用于评估制备的支架的性能。通过检查支架上培养的骨髓间充质干细胞 (BMSCs) 的增殖，优化了纳米纤维中 PAG 和负载 T3 的壳聚糖 NPs 的浓度。
结果：事实证明，加入 2% PAG 具有出色的细胞支持和增殖能力，同时保证 10.8 × 10 ^{- 5} S/cm的电导率。此外，含有 2% 负载 T3 的壳聚糖 NPs 的支架被认为是最具生物相容性的样品。ICC、RT-PCR和流式细胞仪结果显示O4、Olig2、血小板衍生生长因子受体-α（PDGFR-α）、O1、髓鞘/少突胶质细胞糖蛋白（MOG）和髓鞘碱性蛋白（MBP）高表达但胶质纤维酸性蛋白（GFAP）的低表达。
结论：考虑到表面形貌、生物相容性、电导率和基因表达，具有 T3 受控释放的混合 PCL/明胶支架可被认为是一种有希望的候选者，可用作体外模型，通过分离患者的骨髓间充质干细胞来研究患者来源的少突胶质细胞。病理状况，例如疾病或损伤。此外，所得少突胶质细胞可用作患者移植的理想来源。