Complex Materials, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland.
Complex Materials, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland.
Biomater Adv. 2022 Oct;141:213095. doi: 10.1016/j.bioadv.2022.213095. Epub 2022 Aug 27.
Bacterial cellulose is an attractive resource for the manufacturing of sustainable materials, but it is usually challenging to shape it into elaborate three-dimensional structures. Here, we report a manufacturing platform for the creation of complex-shaped cellulose objects by printing inks loaded with bacteria into a silicone-based granular gel. The gel provides the viscoelastic behavior necessary to shape the bacteria-laden ink in three dimensions and the gas permeability required to sustain cellular growth and cellulose formation after the printing process. Using Gluconacetobacter xylinus as model cellulose-producing bacteria, we study the growth and the mechanical properties of cellulose fiber networks obtained upon incubation of the printed inks. Diffusion processes within the ink were found to control the growth of the cellulose structures, which display mechanical properties within the range expected for conventional hydrogels. By keeping the bacteria alive in the printed object, we produce living materials in complex geometries that are able to self-regenerate their cellulose fiber network after damage. Such living hydrogels represent an enticing development towards functional materials with autonomous self-healing and self-regenerating capabilities.
细菌纤维素是制造可持续材料的有吸引力的资源，但通常难以将其塑造成精细的三维结构。在这里，我们报告了一种通过将负载细菌的油墨打印到基于硅树脂的颗粒凝胶中来制造复杂形状纤维素制品的制造平台。该凝胶提供了将细菌负载油墨成型为三维所需的粘弹性以及在打印过程后维持细胞生长和纤维素形成所需的透气性。我们使用木醋杆菌作为模型纤维素生产细菌，研究了印刷油墨孵育后获得的纤维素纤维网络的生长和机械性能。发现油墨内的扩散过程控制着纤维素结构的生长，其机械性能在传统水凝胶的预期范围内。通过使印刷物体中的细菌保持存活，我们以复杂的几何形状生产出活体材料，这些材料能够在受到损伤后自行再生其纤维素纤维网络。这种活体水凝胶是朝着具有自主自修复和自我再生能力的功能材料的诱人发展。
