Exploring the Future of Hydrogels in Rapid Prototyping: A Review on Current Trends and Limitations

Abstract

The combined use of hydrogels and rapid prototyping techniques has been an exciting route in developing tissue engineering scaffolds for the past decade. Hydrogels tend to be an interesting starting material for soft, and lately even 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 predetermined 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 is made between (1) laser-based, (2) nozzle-based and (3) printer-based systems. Special attention is given to current trends and limitations regarding the respective techniques. Each of these techniques is 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 be overcome either during or after post-processing the scaffolds, depending on the applied technology and materials. © Springer Science+Business Media New York 2013.