Non-swelling Hydrogel-based Microfluidic Chips
Hydrogel-based microfluidics are more biologically relevant than the conventional polydimethylsiloxane (PDMS) chips, but the inherited swelling of hydrogels leads to the decrease in mechanical performance and deformation of the as-prepared structure in their manufacture and application processing. Non-swelling hydrogel is, for the first time, utilized to construct the microfluidic chips in this study, which is fabricated by covalently cross-linking of the biocompatible copolymer of di-acrylated Pluronic F127 (F127-DA). Attributed to the non-swelling property, the hydrogel-based microfluidics maintain the as-prepared mechanical strength and channel morphology when equilibrated in aqueous solution at 37°C. Moreover, the microfluidic chips are autoclavable and show an appropriately slow degradation rate by performing the stability within 21 days of incubation. Based on these, a vessel-on-a-chip is established via seeding human umbilical vein endothelial cells (HUVECs) on the microchannel surfaces inside the microfluidic. Under 6 days of perfusion culture with physiologically relevant shear stress of 5 dyne/cm2, the HUVECs in the chip show responsibility to fluid shear stress and expresses higher endothelial functions than the corresponding static culture. Therefore, the non-swelling hydrogel-based microfluidics should be potentially applicable for cell/tissue-related applications, performing much better than conventional PDMS as well as the existing hydrogel based-microfluidics.