The Integrations of Biomaterials and Rapid Prototyping Techniques for Intelligent Manufacturing of Complex Organs - Advances in Biomaterials Science and Biomedical Applications - page 450

constructs can be stored at low temperature (below -80℃) directly after the fabrication stage
(Figure 6). This incorporation technique represents a significant advancement towards the
cell-laden product storage and transport, potentially resulting in labor and resource saving,
clinical availability and medical convenience [80-82]. With the gelatin-based hydrogel vari‐
ous bio-factors including macromolecular cell growth factors, small chemical regulators, and
even genes/drugs can be easily incorporated to the deposition or assembling systems. This
approach is suitable for some special natural thermosetting polymers' (e.g. gelatin and agar‐
ose) deposition and opens a new avenue for complex organ manufacturing.
Figure 6. The combination of cell assembly and cryopreservation techniques, developed in prof. XH Wang' group
[80-82].
4.4. The double-nozzle low-temperature deposition manufacturing (DLDM) system
The creation of a geometrically complex branched vascular system is a subject of broad fun‐
damental and technological interest in complex organ manufacturing. With the DLDM sys‐
tem it is easy to deposit two different material systems, especially both synthetic and natural
polymer systems simultaneously in a construct (Figure 7). Grid, tubular and elliptic struc‐
tures with both synthetic and natural polymers, such as PU/gelatin and PU/collagen, have
been produced at a low-temperature range of -20 - -30 ℃ [61-64] . As shown in Figure 7C, PU