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AUTHOR Li, Jianfeng and Reimers, Armin and Dang, Ka My and Brunk, Michael G. K. and Drewes, Jonas and Hirsch, Ulrike M. and Willems, Christian and Schmelzer, Christian E. H. and Groth, Thomas and Nia, Ali Shaygan and Feng, Xinliang and Adelung, Rainer and Sacher, Wesley D. and Schütt, Fabian and Poon, Joyce K. S.
Title 3D printed neural tissues with in situ optical dopamine sensors [Abstract]
Year 2023
Journal/Proceedings Biosensors and Bioelectronics
Engineered neural tissues serve as models for studying neurological conditions and drug screening. Besides observing the cellular physiological properties, in situ monitoring of neurochemical concentrations with cellular spatial resolution in such neural tissues can provide additional valuable insights in models of disease and drug efficacy. In this work, we demonstrate the first three-dimensional (3D) tissue cultures with embedded optical dopamine (DA) sensors. We developed an alginate/Pluronic F127 based bio-ink for human dopaminergic brain tissue printing with tetrapodal-shaped-ZnO microparticles (t-ZnO) additive as the DA sensor. DA quenches the autofluorescence of t-ZnO in physiological environments, and the reduction of the fluorescence intensity serves as an indicator of the DA concentration. The neurons that were 3D printed with the t-ZnO showed good viability, and extensive 3D neural networks were formed within one week after printing. The t-ZnO could sense DA in the 3D printed neural network with a detection limit of 0.137 μM. The results are a first step toward integrating tissue engineering with intensiometric biosensing for advanced artificial tissue/organ monitoring.
AUTHOR Liu, Chuan and Campbell, Scott B. and Li, Jianzhao and Bannerman, Dawn and Pascual-Gil, Simon and Kieda, Jennifer and Wu, Qinghua and Herman, Peter R. and Radisic, Milica
Title High Throughput Omnidirectional Printing of Tubular Microstructures from Elastomeric Polymers [Abstract]
Year 2022
Journal/Proceedings Advanced Healthcare Materials
Abstract Bioelastomers have been extensively used in biomedical applications due to their desirable mechanical strength, tunable properties, and chemical versatility; however, 3D printing bioelastomers into microscale structures has proven elusive. Herein, a high throughput omnidirectional printing approach via coaxial extrusion is described that fabricated perfusable elastomeric microtubes of unprecedently small inner diameter (350-550 μm) and wall thickness (40-60 μm). The versatility of this approach was shown through the printing of two different polymeric elastomers, followed by photocrosslinking and removal of the fugitive inner phase. Designed experiments were used to tune the dimensions and stiffness of the microtubes to match that of native ex vivo rat vasculature. This approach afforded the fabrication of multiple biomimetic shapes resembling cochlea and kidney glomerulus and afforded facile, high-throughput generation of perfusable structures that can be seeded with endothelial cells for biomedical applications. Post-printing laser micromachining was performed to generate numerous micro-sized holes (5-20 μm) in the tube wall to tune microstructure permeability. Importantly, for organ-on-a-chip applications, the described approach took only 3.6 minutes to print microtubes (without microholes) over an entire 96-well plate device, in contrast to comparable hole-free structures that take between 1.5 to 6.5 days to fabricate using a manual 3D stamping approach. This article is protected by copyright. All rights reserved