2D Stem Cell Culture on Microfluidic Generated Hydrogel Beads

Stem cells capacity to self-renew and differentiate into specialized cell types, endow them with great promises in regenerative medicine. It is believed that the stem cells microenvironment plays a significant role in regulating their fate. However, with exception to embryonic stem cells, there is currently no tractable methods to control stem cells expansion in vitro. Microcarriers were shown to yield enhanced cell expansion compared to conventional cell culture. Nevertheless, the materials used for microcarriers fabrication do not offer the possibility to tailor their physicochemical properties to cell-specific requirements. To fill this technological gap, we propose to develop versatile hydrogel microcarriers with tunable mechanical properties and tailored surface modification. The combination of microfluidic droplet generation and poly(ethylene glycol)-based hydrogels allow the generation of monodisperse hydrogel microcarriers. Chemical moieties on the microcarriers surface enable versatile plug-n-play surface modifications. Microcarriers functionalized with thiolated adhesion ligand were successfully used for cell culture. Furthermore, magnetic particle incorporation within hydrogel microcarriers facilitated their handling during cell culture. To validate our hydrogel microcarriers, we characterized the culture of fibroblasts and HEK cells over 5 days. An increased number of cells were recovered with the hydrogel microcarriers compared to conventional culture. Finally, we were able to culture human mesenchymal stem cells on our hydrogel microcarriers. Altogether, we demonstrated the proof-of-principle experiments for the generation of customized hydrogel microcarriers for stem cell expansion in vitro. The presented technology will offer great promises in the future