Coaxial nozzle-assisted 3D bioprinting with built-in microchannels for nutrients delivery

Recent cell printing systems for tissue engineering

“…The submerged-in-crosslinker cell printing process, referred to as drop-on-demand printing, has been applied to the inkjet [39,40] , laser-assisted [41] , and extrusion-based [42,43] cell printing processes to build 3D structures with relatively low-viscosity bioinks. Xu et al [39] and Boland et al [40] built the drop-on-demand printing apparatus shown in , which uses a layer-by-layer-sinking plate in the crosslinker-filled chamber, and the alginate-based bioink was printed on the surface of the crosslinking liquid.…”

“…They coated the surface of a printing plate, instead of using a lifting stage, and printed the bioink in a CaCl 2 solution to build a biaxially porous 3D scaffold, which created pores between the deposited layers. Gao et al [43] modified the submerged crosslinking cell print-ing process using a c ore/shell nozzle. They extruded the crosslinked solution through the core and the bioink through the shell to create a hollow tube-shaped 3D structure.…”

“…For applications in extrusion-based cell printing, a dual or core/shell nozzle is occasionally used as an alternative crosslinking method, as in the study described above [43][44][45][46] . The core/shell fibrous collagenalginate hydrogel was proposed by Perez et al [44] ( ).…”

“…The surfaces of the struts can be constantly indurated, and the stability of the scaffold increases through the continuous crosslinking of the previously printed layers. This method formed a 3D structure easy and more consistently than the submerged crosslinking technique, since the submerged process contained a high possibility of the bioink floating in the crosslinking solution during the printing process and required additional treatment, such as polyethylenimine (PEI) surface coating [42,47] or a layer-by-layer interactively moving stage [39][40][41]43] .…”

Laboratory 3D printing system

“…On the other side cheap and simple home printers in mass focus on only one printing method -fused deposition modeling (FDM). In most of cases, such as inkjet printing [2][3][4], different kind of bioprinting [3][4][5], laser sintering [6], gel printing [7] or even FDM [8,9] research teams develop their own setup. In many respects, it is connected with the problems in adapting, modifying or expanding the functionality of 3D printers, whose design and software are proprietary of commercial companies.…”