Figure 9.

A combined four-nozzle 3D organ bioprinting technology created in Prof. Wang’s laboratory at Tsinghua University in 2013 [20,50]: (a) equipment of the combined four-nozzle 3D organ bioprinter; (b) working state of the combined four-nozzle 3D organ printer; (c) a CAD model representing a large-scale vascularized and innervated hepatic tissue; (d) a semielliptical 3D construct containing a poly(lactic-co-glycolic acid) (PLGA) overcoat, a hepatic tissue made from hepatocytes in a gelatin/chitosan hydrogel, a branched vascular network with fully confluent endothelialized ASCs on the inner surface of the gelatin/alginate/fibrin hydrogel, and a hierarchical neural (or innervated) network made from Shwann cells in the gelatin/hyaluronate hydrogel; the maximal diameter of the semiellipse can be adjusted from 1 mm to 2 cm according to the CAD model; (e) a cross section of (d), showing the endothelialized ASCs and Schwann cells around a branched channel; (f) a large bundle of nerve fibers formed in (d); (g) hepatocytes underneath the PLGA overcoat; (h) an interface between the endothelialized ASCs and Schwann cells in (d); (i) some thin nerve fibers.