Environmental cues are decisive parameters for controlling cell behaviour. Gaining control over such cues not only enables us to understand the behaviour of cells, but also to control it by the use of synthetic materials. Synthetic 3D microstructured hydrogels are promising materials for mimicking the organized and dense extracellular environment. For their fabrication, it is important to use methods that can generate many samples at low cost to achieve high throughput applications in the future. We hereby present a novel synthetic cell environment, which is based on hydrogels equipped with an interconnected 3D microchannel architecture, with tuneable stiffnesses and controllable biofunctionalization. Two basic components determine this environment: First, a ZnO-tetrapod based sacrificial template, which determines the microarchitecture of the microchannels.  Secondly, a hydrogel precursor mixture into which the ZnO ceramic template is embedded. After polymerization of the hydrogel, the template is dissolved by acid treatment, and the microchannels remain stable in the hydrogel without collapsing. Mechanical properties of the hydrogels can be tuned by varying the crosslinker concentration. We mainly use polyacrylamide (PAAm) as hydrogel. We have shown that human pathogenic Acanthamoeba castellanii can migrate into the 3D microstructured PAAm hydrogels and stay viable for several days.  They are even captured by the specific microstructure of the hydrogel. Furthermore, different biofunctionalizations can be applied to attach specific adhesion proteins (e.g. collagen or fibronectin) that facilitate mammalian cell adhesion and migration.  In conclusion, our microchannel-containing material can be used to control cell behaviour in an adjusted 3D environment by varying the mechanical properties and biofunctionalization of the hydrogel. Therefore, the material also has the potential to be used in implants, where soft and porous 3D environments are desirable. 
 Y. K. Mishra et al., Materials Today 21, 2018, 631-651.
 S. B. Gutekunst et al., ACS Applied Biomaterials 2018 (Under Revision).