Szewczyk Piotr K, Metwally Sara, Karbowniczek Joanna E, Marzec Mateusz M, Stodolak-Zych Ewa, Gruszczyński Adam, Bernasik Andrzej, Stachewicz Urszula
ACS Biomater Sci Eng. 2019 Feb 11;5(2):582-593. doi: 10.1021/acsbiomaterials.8b01108. Epub 2019 Jan 3.
This study represents the unique analysis of the electrospun scaffolds with the controlled and stable surface potential without any additional biochemical modifications for bone tissue regeneration. We controlled surface potential of polyvinylidene fluoride (PVDF) fibers with applied positive and negative voltage polarities during electrospinning, to obtain two types of scaffolds PVDF(+) and, PVDF(-). The cells' attachments to PVDF scaffolds were imaged in great details with advanced scanning electron microscopy (SEM) and 3D tomography based on focus ion beam (FIB-SEM). We presented the distinct variations in cells shapes and in filopodia and lamellipodia formation according to the surface potential of PVDF fibers that was verified with Kelvin probe force microscopy (KPFM). Notable, cells usually reach their maximum spread area through increased proliferation, suggesting the stronger adhesion, which was indeed double for PVDF(-) scaffolds having surface potential of -95 mV. Moreover, by tuning the surface potential of PVDF fibers, we were able to enhance collagen mineralization for possible use in bone regeneration. The scaffolds built of PVDF(-) fibers demonstrated the greater potential for bone regeneration than PVDF(+), showing after 7 days in osteoblasts culture produce well-mineralized osteoid required for bone nodules. The collagen mineralization was confirmed with energy dispersive X-ray spectroscopy (EDX) and Sirius Red staining, additionally the cells proliferation with fluorescence microscopy and Alamar Blue assays. The scaffolds made of PVDF fibers with the similar surface potential to the cell membranes promoting bone growth for next-generation tissue scaffolds, which are on a high demand in bone regenerative medicine.
本研究对具有可控且稳定表面电位的电纺支架进行了独特分析，该支架无需任何额外的生化修饰即可用于骨组织再生。在静电纺丝过程中，我们通过施加正电压和负电压极性来控制聚偏氟乙烯（PVDF）纤维的表面电位，从而获得两种类型的支架PVDF(+)和PVDF(-)。利用先进的扫描电子显微镜（SEM）和基于聚焦离子束的3D断层扫描（FIB-SEM）对细胞在PVDF支架上的附着情况进行了详细成像。我们展示了根据PVDF纤维表面电位不同而在细胞形状以及丝状伪足和片状伪足形成方面的明显差异，这一点通过开尔文探针力显微镜（KPFM）得到了验证。值得注意的是，细胞通常通过增加增殖来达到其最大铺展面积，这表明其具有更强的附着力，对于表面电位为 -95 mV的PVDF(-)支架而言，附着力确实增强了一倍。此外，通过调节PVDF纤维的表面电位，我们能够增强胶原蛋白矿化，以用于可能的骨再生。由PVDF(-)纤维构建的支架在骨再生方面显示出比PVDF(+)更大的潜力，在成骨细胞培养7天后，其产生了骨结节所需的矿化良好的类骨质。通过能量色散X射线光谱（EDX）和天狼星红染色证实了胶原蛋白矿化，另外通过荧光显微镜和阿拉玛蓝测定法对细胞增殖情况进行了检测。由表面电位与细胞膜相似的PVDF纤维制成的支架可促进骨生长，适用于下一代组织支架，这在骨再生医学中具有很高的需求。
