Complex Tissue Regeneration Department, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, The Netherlands.
Biomed Mater. 2020 Jun 26;15(4):045020. doi: 10.1088/1748-605X/ab7b3c.
Developing, homeostatic, and regenerating tissues are full of various gradients, including mechanical, chemical, porosity and growth-factor gradients. However, it remains challenging to replicate these gradients using common tissue engineering approaches. Here, we use electrospinning to create scaffolds with in-depth gradients. We created a fiber diameter gradient and pore size gradient throughout the depth of electrospun (ESP) scaffolds by a continuous gradient of polymer concentration. As an alternative to this established method, we developed a novel method to create fiber diameter gradients by changing the voltage on both needle and collector, keeping the total voltage constant. In this way, fiber diameter could be changed in a gradient matter by focusing the electrospinning spot. Using this method, we created a fiber diameter and pore size gradient, while keeping all other parameters constant. Lastly, we developed a novel method to create functional group gradients, which can potentially be used in a wide variety of polymer solutions to couple peptides and proteins to ESP scaffolds. A scaffold with an in-depth gradient of functional groups was created by adding functionalized poly(ethylene glycol) additives to the polymer solution, a novel method with potentially wide applications. The techniques demonstrated here could be applied to a wide variety of polymers and applications and can aid in developing physiologically relevant gradient scaffolds.
发育、稳态和再生组织充满了各种梯度，包括机械、化学、孔隙率和生长因子梯度。然而，使用常见的组织工程方法复制这些梯度仍然具有挑战性。在这里，我们使用静电纺丝来创建具有深度梯度的支架。我们通过聚合物浓度的连续梯度在整个静电纺丝（ESP）支架深度上创建了纤维直径梯度和孔径梯度。作为对这种既定方法的替代，我们开发了一种通过改变针和收集器上的电压来创建纤维直径梯度的新方法，保持总电压恒定。通过这种方式，可以通过聚焦静电纺丝点以梯度方式改变纤维直径。使用这种方法，我们创建了纤维直径和孔径梯度，同时保持所有其他参数不变。最后，我们开发了一种创建功能基团梯度的新方法，该方法可用于各种聚合物溶液，将肽和蛋白质偶联到 ESP 支架上。通过向聚合物溶液中添加功能化的聚（乙二醇）添加剂来创建具有深度功能基团梯度的支架，这是一种具有广泛应用潜力的新方法。这里展示的技术可以应用于各种聚合物和应用，有助于开发具有生理相关性的梯度支架。
