Extrusion and Microfluidic‐Based Bioprinting to Fabricate Biomimetic Tissues and Organs

Abstract

Next generation engineered tissue constructs with complex and ordered architectures aim to better mimic the native tissue structures, largely due to advances in 3D bioprinting techniques. Extrusion bioprinting has drawn tremendous attention due to its widespread availability, cost‐effectiveness, simplicity, and its facile and rapid processing. However, poor printing resolution and low speed have limited its fidelity and clinical implementation. To circumvent the downsides associated with extrusion printing, microfluidic technologies are increasingly being implemented in 3D bioprinting for engineering living constructs. These technologies enable biofabrication of heterogeneous biomimetic structures made of different types of cells, biomaterials, and biomolecules. Microfluiding bioprinting technology enables highly controlled fabrication of 3D constructs in high resolutions and it has been shown to be useful for building tubular structures and vascularized constructs, which may promote the survival and integration of implanted engineered tissues. Although this field is currently in its early development and the number of bioprinted implants is limited, it is envisioned that it will have a major impact on the production of customized clinical‐grade tissue constructs. Further studies are, however, needed to fully demonstrate the effectiveness of the technology in the lab and its translation to the clinic.

Fabrication of Carboxymethyl Chitosan Nanoparticles to Deliver Paclitaxel for Melanoma Treatment

“…[37] The emergence of microfluidic reactors began in the early 1990 s and, as a result of significant developments in design, fabrication, and utilization, have become attractive devices for pharmaceutical, biotechnology and chemical industries in recent years. [38,39] Microfluidic devices have recently applied for continuous nanoprecipitation production and played a key role in the development of highperformance drug NCs and encapsulated drugs. PTX NCs are synthesized by precipitation in the inner stream of dispersed phase to create the NCs core.…”

Multicomponent polysaccharide alginate-based bioinks

“…extrusion, inkjet, and microfluidic bioprinting). [24][25][26][27] Extrusion is probably the most widely employed bioprinting methodology, employing the controlled extrusion of long hydrogel filaments from a dispensing cartridge. 25 This technique can be applied with a variety of bioinks ranging from low to high viscosities.…”

“…However, because alginate is easy to gel at room temperature, allowing the encapsulation of living cells before the printing process, it can be readily applied to other bioprinting methods. The reader is, therefore also referred to a number of additional reviews and research articles for a more detailed discussion, 24,[26][27][28][29][30][31][32][33][34] and we will go on to briefly review inkjet and microfluidic bioprinting technologies, for which the properties of this polymer are particularly advantageous, later in this article.…”

“…Another bioprinting technology that can be applied to alginate-based bioinks is microfluidic bioprinting, which is based on the precise flow of small amounts of fluids (10 À9 to 10 À18 L volumes) through microchannels. 26 This technique allows the fabrication of high resolution 3D printed microfibers or microbeads with efficient control of both morphology and dimensions. 26 Noteworthy applications of microfluidic technology include the production of 3D printed vascular structures and cellular organoids.…”

“…26 This technique allows the fabrication of high resolution 3D printed microfibers or microbeads with efficient control of both morphology and dimensions. 26 Noteworthy applications of microfluidic technology include the production of 3D printed vascular structures and cellular organoids. 27,60,61 As described above for the inkjet technique, in this case, the concentration of alginate and of the cross-linker once again has a remarkable effect on the features of the bioprinted structures.…”