Scaffold‐free inkjet printing of three‐dimensional zigzag cellular tubes

Abstract

The capability to print three-dimensional (3D) cellular tubes is not only a logical first step towards successful organ printing but also a critical indicator of the feasibility of the envisioned organ printing technology. A platform-assisted 3D inkjet bioprinting system has been proposed to fabricate 3D complex constructs such as zigzag tubes. Fibroblast (3T3 cell)-based tubes with an overhang structure have been successfully fabricated using the proposed bioprinting system. The post-printing 3T3 cell viability of printed cellular tubes has been found above 82% (or 93% with the control effect considered) even after a 72-h incubation period using the identified printing conditions for good droplet formation, indicating the promising application of the proposed bioprinting system. Particularly, it is proved that the tubular overhang structure can be scaffold-free fabricated using inkjetting, and the maximum achievable height depends on the inclination angle of the overhang structure. As a proof-of-concept study, the resulting fabrication knowledge helps print tissue-engineered blood vessels with complex geometry.

Study of extrudability and standoff distance effect during nanoclay-enabled direct printing

“…As the internal scaffold material during extrusion, Laponite XLG is added to prepare the NIPAAm-Laponite nanocomposite hydrogel precursor to investigate the improvement of the bioink extrudability. For comparison, high-concentration NaAlg, a natural polysaccharide widely used for biorelated applications [6,7,9,10,18], is selected as a benchmark bioink material herein. In summary, four biocompatible materials (NIPAAm, Laponite, NIPAAm-Laponite, and NaAlg) are extruded through a transparent glass nozzle to study their extrudability, and the velocity field distribution is measured to evaluate the effects of nanoclay on the extrudability.…”

3D bioprinting for cell culture and tissue fabrication

“…Xu et al employed a platform-assisted 3D inkjet bioprinting system to fabricate zigzag tube structure, in which fibroblast retained cell viability of above 80% in 3 days of culture. The results illustrated that vessel-like construct with complex geometry could be successfully fabricated by 3D bioprinting technique [35]. Miller et al [36] constructed a rigid filament network using endothelial cells encapsulated within carbohydrate glass (Fig.…”

3D Miniaturization of Human Organs for Drug Discovery

“…Furthermore, the viscosity of the hydrogel must be low (<10 mPa s) to ensure droplet forming and reduce nozzle clogging. [152] The significant limitation of this technology is the need for low viscosity ink. The low viscosity ink causes the printed structures to be weak, thus affecting their durability to external stresses after implantation.…”