3D printed neural tissues with in situ optical dopamine sensors

• Published in: Biosensors & bioelectronics 2023-02, Vol.222, p.114942-114942, Article 114942
• Main Authors: Li, Jianfeng, Reimers, Armin, Dang, Ka My, Brunk, Michael G.K., Drewes, Jonas, Hirsch, Ulrike M., Willems, Christian, Schmelzer, Christian E.H., Groth, Thomas, Nia, Ali Shaygan, Feng, Xinliang, Adelung, Rainer, Sacher, Wesley D., Schütt, Fabian, Poon, Joyce K.S.
• Format: Article
• Language: English
• Subjects: 3D bioprinting; Bioink development; Bioprinting; Biosensing; Biosensing Techniques; Dopamine; Humans; Neural tissue engineering; Printing, Three-Dimensional; t-ZnO; Tissue Engineering - methods; Tissue Scaffolds - chemistry; Zinc Oxide
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2022.114942

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. •t-ZnO microparticles could serve as an efficient optical dopamine sensor without the need of functionalization.•3D bioprinting t-ZnO with neuronal cell laden bioink doesn't influence neural tissue formation and neural network projection.•Embedded t-ZnO in the 3D printed neural tissue could serve as a sensor for dopamine releasing with high resolution.•This work shows a route toward smart tissue/organ fabrication with integration of in situ sensors.