서강대학교

초록/요약

Despite the significant advancements in tissue engineering to mimic native tissue constructs, fabrication of bifurcating hierarchical vessels with controlled vessel lumen and wall thickness still pose a great challenge. The importance of fabricating vascular networks with tunable physical properties is to mimic the structural and functional traits of native vascular system to drive and maintain the fluids inside the vessels. Here, we present a novel method to fabricate bifurcating vessels, develop hierarchical systems and ultimately provide a platform to study fluid transport through the artificial vessels. In particular, we designed a diffusive bioprinting method by incorporating calcium chloride in Pluronic F127 (PFCa) and subsequently casting alginate and gelatin mixture over the extruded PFCa ink. Pluronic F127 blended with calcium chloride shows shear-thinning behavior which enables preservation of extruded filamentary shape and bifurcation of the vessels. After casting alginate/gelatin mixture on extruded PFCa, calcium circumferentially diffuse and crosslink alginate, yielding a tubular hydrogel construct that physically mimics vessels. The structural properties of the vessels are tuned by changing the calcium diffusion time and the concentration of calcium in PFCa. This diffusive bioprinting technique enables bifurcation of the vessels and hierarchical vasculature that obey Murray’s law, such that the cost for transport and maintenance of the transport materials is minimized. This flexible bifurcating hierarchical vessels made out of hydrogel could also provide a potential platform to study the fluid dynamics under mechanical deformation and fabrication of artificial vascular graft for implantation.