Presentation Authors: Xiang Yan*, Nanjing , China, People's Republic of
Introduction: Biofabrication of circumferentially multilayered tubular tissues or organs with cellular heterogeneity remains a challenge in the bioprinting technology. In this study, we introduce a digitally coded coaxial extrusion device that can directly bioprint 3D complex tubular hollow fibers with multiple circumferential layers in a single step.
Methods: In order to improve mechanical strength and stability of the crosslinked matrix, we developed a customized blend bioink formulation by mixing eight-arm poly (ethylene glycol) (PEG) acrylate with tripentaerythritol core (PEGOA) in the GelMA/alginate hydrogel. We designed the multichannel coaxial extrusion system (MCCES), consisting of three concentrically assembled needles, which could fabricate multilayered hollow tubes, consisting of continuously altering shapes and sizes, without the need of changing the nozzles. We further demonstrated precise control over the architecture of the bioprinted tubes constructing a wide range of multilayered hollow tubes with desired diameters and numbers of circumferential layers at the same time, in a continuous manner, by switching the coaxial channels on or off at desire intervals. We tested our MCCES along with the customized bioink for bioprinting of biomimetic urothelial tissue construct and evaluated its biofunctionality via immunocytochemical staining at day 14 after bioprinting. Similar to cannular urothelial tissue, vascular tissue constructs were bioprinted and further analyzed.
Results: The immunocytochemical analysis of the bioprinted tissue confirmed its proper biofunctionality. Furthermore, these bioprinted cannular tissues can be actively perfused with fluids and nutrients to promote growth and proliferation of the embedded cell types. We confirmed with our designed MCCES, we could bioprint circumferentially multilayered hollow tissue constructs using the custuomized GelMA-based bioink.
Conclusions: In summary, this generalized bioprinting method can be extended for the fabrication of many different types of tubular tissues possessing hierarchically layered structures, using a single, digitally controlled extruder system. We believe our system has the potential to expand current bioprinting platforms to create multitude of tubular tissue architectures for tissue regeneration and modeling.