Schaub Nicholas J, D'Amato Anthony R, Mason Andrew, Corr David T, Harmon Erin Y, Lennartz Michelle R, Gilbert Ryan J
a Department of Biomedical Engineering , Rensselaer Polytechnic Institute , Troy , NY , USA.
b Center for Biotechnology & Interdisciplinary Studies , Rensselaer Polytechnic Institute , Troy , NY , USA.
J Biomater Sci Polym Ed. 2017 Sep;28(13):1303-1323. doi: 10.1080/09205063.2017.1321345. Epub 2017 Apr 26.
Currently, it is unknown how the mechanical properties of electrospun fibers, and the presentation of surface nanotopography influence macrophage gene expression and protein production. By further elucidating how specific fiber properties (mechanical properties or surface properties) alter macrophage behavior, it may be possible to create electrospun fiber scaffolds capable of initiating unique cellular and tissue responses. In this study, we determined the elastic modulus and rigidity of fibers with varying topographies created by finely controlling humidity and including a non-solvent during electrospinning. In total,five fiber scaffold types were produced. Analysis of fiber physical properties demonstrated no change in fiber diameter amongst the five different fiber groups. However, the four different fibrous scaffolds with nanopits or divots each possessed different numbers of pits with different nanoscale dimensions. Unpolarized bone marrow derived murine macrophages (M0), macrophages polarized towards a pro-inflammatory phenotype (M1), or macrophages polarized towards anti-inflammatory phenotype (M2b) were placed onto each of the scaffolds and cytokine RNA expression and protein production were analyzed. Specific nanotopographies did not appreciably alter cytokine production from undifferentiated macrophages (M0) or anti-inflammatory macrophages (M2b), but a specific fiber (with many small pits) did increase IL-12 transcript and IL-12 protein production compared to fibers with small divots. When analyzing the mechanical properties between fibers with divots or with many small pits,divoted fibers possessed similar elastic moduli but different stiffness values. In total,we present techniques capable of creating unique electrospun fibers. These unique fibers have varying fiber mechanical characteristics and modestly modulate macrophage cytokine expression.
目前，尚不清楚电纺纤维的机械性能以及表面纳米形貌如何影响巨噬细胞基因表达和蛋白质产生。通过进一步阐明特定的纤维特性（机械性能或表面性能）如何改变巨噬细胞行为，或许有可能制造出能够引发独特细胞和组织反应的电纺纤维支架。在本研究中，我们通过精细控制湿度并在电纺过程中加入非溶剂，确定了具有不同形貌的纤维的弹性模量和刚性。总共制备了五种纤维支架类型。纤维物理性能分析表明，五个不同纤维组之间的纤维直径没有变化。然而，四种带有纳米凹坑或凹陷的不同纤维支架各自具有不同数量、不同纳米尺度尺寸的凹坑。将未极化的骨髓来源小鼠巨噬细胞（M0）、向促炎表型极化的巨噬细胞（M1）或向抗炎表型极化的巨噬细胞（M2b）置于每种支架上，并分析细胞因子RNA表达和蛋白质产生情况。特定的纳米形貌并未明显改变未分化巨噬细胞（M0）或抗炎巨噬细胞（M2b）的细胞因子产生，但与带有小凹陷的纤维相比，一种特定的纤维（有许多小凹坑）确实增加了IL - 12转录本和IL - 12蛋白的产生。在分析带有凹陷或有许多小凹坑的纤维之间的机械性能时，带有凹陷的纤维具有相似的弹性模量，但刚度值不同。总之，我们展示了能够制造独特电纺纤维的技术。这些独特的纤维具有不同的纤维机械特性，并适度调节巨噬细胞细胞因子表达。
