Human neuronal cultures are promising tools for studying e.g. disease mechanisms, drug response or developmental biology. However, traditional flat 2D cultures on top of rigid surface fail to offer in vivo like niches to the cells. 3D cell cultures are able to overcome some of the limitations occurring in 2D cultures by offering cells artificial extracellular matrix (ECM) and more in vivo mimicking environment. Highly biocompatible nanocellulose based hydrogels have proven to be potential for 3D culturing of various cell types. These plant derived nanofibrillar cellulose (NFC) hydrogels mimic native soft tissue ECM in fiber size and in mechanical properties, thus providing cells more in vivo like growth environment.
In this study pre-differentiated human pluripotent stem cell derived neurons where cultured as encapsulated within the GrowDex® NFC hydrogel from UPM-Kymmene Oyj (Finland). Experiments were performed with concentration of five million cells per ml of hydrogel and cells were cultured for two weeks. The formation of neuronal networks inside the hydrogels was evaluated by immunocytochemical staining against neuronal markers after the two weeks with confocal imaging. Sample preparation with these one component hydrogels was convenient and the prepared 3D cultures had homogenous cell distribution. During two weeks culturing period, a robust neurite outgrowth was observed in all dimensions. In best cases, the neuronal network filled remarkable volume of the whole hydrogel block. Based on these results it can be concluded that studied GrowDex hydrogel offered very good growth environment for human neural cells and the NFC hydrogel based neural cultures should be studied further.
Image text: Figure 1: Nanofibrillar cellulose hydrogel supported robust neurite outgrowth in all directions.