Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy.
Department of Biomaterials, INNOVENT e. V., 07745 Jena, Germany.
Molecules. 2020 Jul 11;25(14):3176. doi: 10.3390/molecules25143176.
Electrospun PLGA microfibers with adequate intrinsic physical features (fiber alignment and diameter) have been shown to boost teno-differentiation and may represent a promising solution for tendon tissue engineering. However, the hydrophobic properties of PLGA may be adjusted through specific treatments to improve cell biodisponibility. In this study, electrospun PLGA with highly aligned microfibers were cold atmospheric plasma (CAP)-treated by varying the treatment exposure time (30, 60, and 90 s) and the working distance (1.3 and 1.7 cm) and characterized by their physicochemical, mechanical and bioactive properties on ovine amniotic epithelial cells (oAECs). CAP improved the hydrophilic properties of the treated materials due to the incorporation of new oxygen polar functionalities on the microfibers' surface especially when increasing treatment exposure time and lowering working distance. The mechanical properties, though, were affected by the treatment exposure time where the optimum performance was obtained after 60 s. Furthermore, CAP treatment did not alter oAECs' biocompatibility and improved cell adhesion and infiltration onto the microfibers especially those treated from a distance of 1.3 cm. Moreover, teno-inductive potential of highly aligned PLGA electrospun microfibers was maintained. Indeed, cells cultured onto the untreated and CAP treated microfibers differentiated towards the tenogenic lineage expressing tenomodulin, a mature tendon marker, in their cytoplasm. In conclusion, CAP treatment on PLGA microfibers conducted at 1.3 cm working distance represent the optimum conditions to activate PLGA surface by improving their hydrophilicity and cell bio-responsiveness. Since for tendon tissue engineering purposes, both high cell adhesion and mechanical parameters are crucial, PLGA treated for 60 s at 1.3 cm was identified as the optimal construct.
具有适当内在物理特性(纤维取向和直径)的电纺 PLGA 微纤维已被证明可以促进腱细胞分化,可能是肌腱组织工程的一种有前途的解决方案。然而,PLGA 的疏水性可以通过特定的处理来调整,以提高细胞的生物可用性。在这项研究中,通过改变处理暴露时间(30、60 和 90 秒)和工作距离(1.3 和 1.7 厘米),对具有高度取向微纤维的电纺 PLGA 进行冷等离体(CAP)处理,并对绵羊羊膜上皮细胞(oAECs)的物理化学、机械和生物活性特性进行了表征。CAP 通过在微纤维表面引入新的氧极性官能团,提高了处理材料的亲水性,尤其是当增加处理暴露时间和降低工作距离时。然而,处理暴露时间会影响机械性能,最佳性能在 60 秒后获得。此外,CAP 处理不会改变 oAECs 的生物相容性,并改善细胞在微纤维上的粘附和渗透,尤其是那些在 1.3 厘米距离处理的细胞。此外,高度取向的 PLGA 静电纺丝微纤维的腱诱导潜力得以维持。事实上,在未经处理和 CAP 处理的微纤维上培养的细胞向腱细胞系分化,在细胞质中表达腱调蛋白,这是一种成熟的肌腱标志物。总之,在 1.3 厘米工作距离下对 PLGA 微纤维进行 CAP 处理是通过提高其亲水性和细胞生物响应性来激活 PLGA 表面的最佳条件。由于在肌腱组织工程中,高细胞粘附和机械参数都很重要,因此在 1.3 厘米处处理 60 秒的 PLGA 被确定为最佳构建体。