Department of Biomedical Engineering, Tufts University, Medford, MA, USA.
Biomedical Engineering Program, University of Massachusetts, Lowell, Lowell, MA, USA.
Acta Biomater. 2018 Apr 15;71:379-387. doi: 10.1016/j.actbio.2018.02.035. Epub 2018 Mar 15.
Freeform fabrication has emerged as a key direction in printing biologically-relevant materials and structures. With this emerging technology, complex structures with microscale resolution can be created in arbitrary geometries and without the limitations found in traditional bottom-up or top-down additive manufacturing methods. Recent advances in freeform printing have used the physical properties of microparticle-based granular gels as a medium for the submerged extrusion of bioinks. However, most of these techniques require post-processing or crosslinking for the removal of the printed structures (Miller et al., 2015; Jin et al., 2016) [1,2]. In this communication, we introduce a novel method for the one-step gelation of silk fibroin within a suspension of synthetic nanoclay (Laponite) and polyethylene glycol (PEG). Silk fibroin has been used as a biopolymer for bioprinting in several contexts, but chemical or enzymatic additives or bulking agents are needed to stabilize 3D structures. Our method requires no post-processing of printed structures and allows for in situ physical crosslinking of pure aqueous silk fibroin into arbitrary geometries produced through freeform 3D printing.
3D bioprinting has emerged as a technology that can produce biologically relevant structures in defined geometries with microscale resolution. Techniques for fabrication of free-standing structures by printing into granular gel media has been demonstrated previously, however, these methods require crosslinking agents and post-processing steps on printed structures. Our method utilizes one-step gelation of silk fibroin within a suspension of synthetic nanoclay (Laponite), with no need for additional crosslinking compounds or post processing of the material. This new method allows for in situ physical crosslinking of pure aqueous silk fibroin into defined geometries produced through freeform 3D printing.
自由形态制造已成为打印与生物相关材料和结构的关键方向。随着这项新兴技术的出现，可以在任意几何形状下创建具有微尺度分辨率的复杂结构，而不会受到传统自下而上或自上而下的增材制造方法的限制。最近，自由形态打印的进展利用基于微粒的颗粒凝胶的物理特性作为生物墨水的水下挤压的介质。然而，这些技术中的大多数需要后处理或交联来去除打印结构（Miller 等人，2015 年；Jin 等人，2016 年）[1,2]。在本通讯中，我们介绍了一种在合成纳米粘土（Laponite）和聚乙二醇（PEG）悬浮液中一步凝胶化丝素蛋白的新方法。丝素蛋白已被用作几种生物打印的生物聚合物，但需要化学或酶添加剂或增稠剂来稳定 3D 结构。我们的方法不需要对打印结构进行后处理，并允许通过自由形态 3D 打印产生的任意几何形状对纯丝素蛋白进行原位物理交联。
3D 生物打印已成为一种可以在定义的几何形状中以微尺度分辨率生产生物相关结构的技术。以前已经证明了通过打印到颗粒凝胶介质中制造独立结构的技术，但是这些方法需要交联剂和打印结构的后处理步骤。我们的方法利用合成纳米粘土（Laponite）悬浮液中丝素蛋白的一步凝胶化，无需额外的交联化合物或对材料进行后处理。这种新方法允许通过自由形态 3D 打印产生的定义几何形状对纯丝素蛋白进行原位物理交联。
