Effects of Humidity and Solution Viscosity on Electrospun Fiber Morphology
Effects of Humidity and Solution Viscosity on Electrospun Fiber Morphology
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DOI：
10.1089/ten.tec.2012.0671
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发表时间：
2013-10-01
影响因子：
3
通讯作者：
Cosgriff-Hernandez, Elizabeth
中科院分区：
文献类型：
--
作者：
Nezarati, Roya M.;Eifert, Michelle B.;Cosgriff-Hernandez, Elizabeth
静电纺丝是一种流行的技术，用于制造组织工程支架，由于纤维形态的特殊可调性，可用于控制支架的机械性能，降解速率和细胞行为。虽然调制工艺或溶液参数对纤维形态的影响已被广泛研究，但对环境参数（如湿度）的影响的理解仍然有限。为了解决这一差距，三种聚合物（聚（乙二醇）[PEG]，聚己内酯[PCL]和聚（碳酸酯氨基甲酸酯）[PCU]）在一定范围的相对湿度（RH = 5%-75%）下进行静电纺丝，所得纤维结构用扫描电子显微镜进行表征。低相对湿度（50%）下，根据各个聚合物的特性，观察到三种不同的影响。在PEG体系中，由于在高相对湿度下吸水性增加，纤维断裂和纤维形态损失增加。相比之下，观察到PCL纤维上的表面孔，并假设其是通过蒸气诱导相分离形成的。最后，减少PCU纤维收集发生在高湿度可能是由于增加静电放电。这些发现强调了相对湿度对静电纺丝纤维形态的影响取决于聚合物的疏水性、溶剂与水的相容性和溶剂挥发性。进行了额外的研究，以强调分子量的微小变化可以强烈影响溶液粘度和所得纤维形态。我们建议，溶液粘度，而不是浓度是一个更有用的参数，报告在静电纺丝方法，使再现的结果。总之，本研究进一步阐明了电纺纤维形成的关键机制，可用于制造具有可调和可重复性能的组织工程支架。
Electrospinning is a popular technique to fabricate tissue engineering scaffolds due to the exceptional tunability of fiber morphology that can be used to control scaffold mechanical properties, degradation rate, and cell behavior. Although the effects of modulating processing or solution parameters on fiber morphology have been extensively studied, there remains limited understanding of the impact of environmental parameters such as humidity. To address this gap, three polymers (poly(ethylene glycol) [PEG], polycaprolactone [PCL], and poly(carbonate urethane) [PCU]) were electrospun at a range of relative humidities (RH = 5%-75%) and the resulting fiber architecture characterized with scanning electron microscopy. Low relative humidity (50%), three distinct effects were observed based on individual polymer properties. An increase in fiber breakage and loss of fiber morphology occurred in the PEG system as a result of increased water absorption at high relative humidity. In contrast, surface pores on PCL fibers were observed and hypothesized to have formed via vapor-induced phase separation. Finally, decreased PCU fiber collection occurred at high humidity likely due to increased electrostatic discharge. These findings highlight that the effects of relative humidity on electrospun fiber morphology are dependent on polymer hydrophobicity, solvent miscibility with water, and solvent volatility. An additional study was conducted to highlight that small changes in molecular weight can strongly influence solution viscosity and resulting fiber morphology. We propose that solution viscosity rather than concentration is a more useful parameter to report in electrospinning methodology to enable reproduction of findings. In summary, this study further elucidates key mechanisms in electrospun fiber formation that can be utilized to fabricate tissue engineering scaffolds with tunable and reproducible properties.