Indexed on: 23 Aug '17Published on: 23 Aug '17Published in: Tissue engineering. Part C, Methods
3D bioprinting is a promising technology for manufacturing cell-laden tissue engineered constructs. Larger tissue substitutes, however, require a vascularized network to ensure nutrition supply. Therefore, tailored bioinks combining 3D printability and cell-induced vascularization are needed. We hypothesize that tailored hydrogel blends made of agarose-type I collagen and agarose-fibrinogen are 3D printable and will allow the formation of capillary-like structures by human umbilical vein endothelial cells and human dermal fibroblasts. Samples were casted, incubated for 14 days, analyzed by immunohistology and two-photon laser scanning microscopy. The 3D printability of the hydrogel blends was examined using a drop-on-demand printing system. The rheological behavior was also investigated. Substantial capillary network formation was observed in agarose-type I collagen hydrogel blends with concentrations of 0.2 or 0.5 % collagen and 0.5 % agarose. Furthermore, storage moduli of agarose-collagen blends were significantly increased compared to those of the corresponding single components (448 Pa for 0.5 % agarose, 148 Pa for 0.5 % collagen, 1551 Pa for 0.5 % agarose-0.5 % collagen). Neither the addition of collagen nor fibrinogen significantly impaired the printing resolution. In conclusion, we present a tailored hydrogel blend which can be printed in 3D and in parallel exhibits cell-induced vascularization capability.