An investigation of microfluidic produced hydrogel vesicles for artificial antigen-presenting cell applications

The antigen-presenting cell is the key component in T cell activation pathway, delivering signals and helping T cell detecting and fighting cancers. Research have reported that T cells are mechano-sensitive to the environment. Their activation, differentiation, recognition, and function are regulated by mechanical forces such as contact tension, shear stress, and substrate rigidity. However, the examination on how the stiffness of artificial antigen-presenting cells (aAPCs) affects T cell’s functions remains unknown. Therefore, in this research, a novel microfluidic-based double emulsion droplet (DED) generation chip is proposed to generate monodisperse hydrogel DEDs with tunable stiffness and fluid membrane. Another trapping array device is used to exam the stiffness differences between crosslinked and non-crosslinked Polyethylene (glycol) Diacrylate (PEGDA) hydrogel DEDs. The result shows the hydrogel DEDs have a significant difference in stiffness before and after the UV exposure. The hydrogel DED’s stability decreased as the hydrogel concentration increased. Also, we discovered that the trapping array can be a potential candidate for DED dewetting, as it shortens the dewetting process to less than 20 seconds