Polymer Chemistry & Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 Bis, Ghent 9000, Belgium.
Biomaterials. 2012 Sep;33(26):6020-41. doi: 10.1016/j.biomaterials.2012.04.050. Epub 2012 Jun 7.
The combined potential of hydrogels and rapid prototyping technologies has been an exciting route in developing tissue engineering scaffolds for the past decade. Hydrogels represent to be an interesting starting material for soft, and lately also for hard tissue regeneration. Their application enables the encapsulation of cells and therefore an increase of the seeding efficiency of the fabricated structures. Rapid prototyping techniques on the other hand, have become an elegant tool for the production of scaffolds with the purpose of cell seeding and/or cell encapsulation. By means of rapid prototyping, one can design a fully interconnected 3-dimensional structure with pre-determined dimensions and porosity. Despite this benefit, some of the rapid prototyping techniques are not or less suitable for the generation of hydrogel scaffolds. In this review, we therefore give an overview on the different rapid prototyping techniques suitable for the processing of hydrogel materials. A primary distinction will be made between (i) laser-based, (ii) nozzle-based, and (iii) printer-based systems. Special attention will be addressed to current trends and limitations regarding the respective techniques. Each of these techniques will be further discussed in terms of the different hydrogel materials used so far. One major drawback when working with hydrogels is the lack of mechanical strength. Therefore, maintaining and improving the mechanical integrity of the processed scaffolds has become a key issue regarding 3-dimensional hydrogel structures. This limitation can either be overcome during or after processing the scaffolds, depending on the applied technology and materials.
在过去的十年中，水凝胶和快速原型制造技术的结合为组织工程支架的开发提供了一条令人兴奋的途径。水凝胶是一种很有前途的软组织和最近的硬组织再生材料。它们的应用可以实现细胞的封装，从而提高所构建结构的接种效率。另一方面，快速原型制造技术已成为用于接种细胞和/或细胞封装的支架生产的一种优雅工具。通过快速原型制造，可以设计出具有预定尺寸和孔隙率的完全互连的三维结构。尽管有这种优势，但某些快速原型制造技术不适合或不太适合生成水凝胶支架。因此，在本文中，我们将概述适用于加工水凝胶材料的不同快速原型制造技术。我们将主要对（i）基于激光的、（ii）基于喷嘴的和（iii）基于打印机的系统进行区分。特别关注与各自技术相关的当前趋势和局限性。每种技术都将根据迄今为止使用的不同水凝胶材料进行进一步讨论。使用水凝胶的一个主要缺点是缺乏机械强度。因此，保持和提高处理后的支架的机械完整性已成为与 3D 水凝胶结构相关的关键问题。这种限制可以在处理支架期间或之后克服，具体取决于所应用的技术和材料。
