Poster M12 - 3D printed microfluidic platforms with integrated electrodes for three-dimensional perfusion of macro-scale engineered living materials

Thursday, October 24, 2024

10:00 AM - 11:00 AM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Aishwarya Pantula (she/her/hers)

PhD Candidate
Department of Chemical and Biomolecular Engineering , Johns Hopkins University, Baltimore, MD 21218,USA
Baltimore, Maryland, United States

Co-Author(s)

Derosh George, PhD (he/him/his)

Postdoc fellow
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA, United States
Alisa Fedotova (she/her/hers)

Undergraduate Student
Department of Chemical and Biomolecular Engineering , Johns Hopkins University, United States
AD

Ashwin Damodaran (he/him/his)

Department of Chemical and Biomolecular Engineering , Johns Hopkins University, Baltimore, MD 21218,USA, United States
BZ

Bo Zhou (he/him/his)

Department of Chemical and Biomolecular Engineering , Johns Hopkins University, Baltimore, MD 21218,USA, United States
Itzy Morales Pantoja, PhD (she/her/hers)

Postdoctoral Fellow
Johns Hopkins University
Baltimore, Maryland, United States
LS

Lena Smirnova

Center for Alternatives to Animal Testing (CAAT), Department of Environmental Health and Engineering, Bloomberg School of Public Health Johns Hopkins University, Baltimore, MD, 21205, USA, United States

Primary Investigator(s)

David Gracias, PhD

Professor
Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA; Sidney Kimmel Comprehensive Cancer Center (SKCCC), Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemistry, Materials Science and Engineering, Laboratory for Computational Sensing and Robotics (LCSR), Johns Hopkins University, Baltimore, MD 21218, USA.
Baltimore, Maryland, United States

Introduction: Engineered living materials (ELMs) are composed of live cells in natural or synthetic self-regenerating matrices, exhibiting life-like traits such as biosynthesis, self-growth, self-organization, self-healing, and environmental responsiveness. Demonstrated with cells, bacteria, and, more recently, organoids, ELMs significantly advance the mimicry of biological systems for studying diseases, development, and environmental interactions. Despite their potential, ELMs often face challenges such as inadequate nutrient diffusion and waste removal, limiting their viability and functional complexity, particularly in constructs larger than 300-500 microns and over long periods ranging from days to weeks. Here, we describe 3D printed microfluidic platforms encased within a shell, integrated with microelectrode grids to enhance three-dimensional media perfusion, chemical patterning, and waste removal. Using gels and cerebral organoids as model systems, we present the design, simulation, and optimization of these microfluidic transport systems for improved viability and functionality.

Materials and

Methods: We developed a computational model using COMSOL Multiphysics to simulate necrosis in live cell culture using a cerebral organoid system. We used our model to conduct parametric studies on the microfluidic device to optimize design parameters like pipe layout. After evaluating all materials for cell viability and resolution, we used a combination of 3D printing and lithography to manufacture the microfluidic device and electrodes (1), followed by perfusion and electrophysiology studies on gels and model cerebral organoid systems.
(1) Qi Huang et al. ,Shell microelectrode arrays (MEAs) for brain organoids. Sci. Adv.8,eabq5031(2022).DOI:10.1126/sciadv.abq5031

Results, Conclusions, and Discussions:

Results: We describe the fabrication, material testing, and surface treatment protocols of our microfluidic platform. Our findings indicate good feature resolution and reproducibility, continuous perfusion without blocked tubes, and effective integration between the electrodes and the device. Additionally, we demonstrate the ability of our device to support robust long-term culture with perfusion. We compare necrotic tissue within large organoids with and without perfusion and record the electrophysiology of the organoid as it grows in the device.

Conclusions: In summary, we developed tunable and customizable 3D printed microfluidic platforms that enable macro-scale continuous three-dimensional perfusion, long-term culture, and electrophysiological monitoring of ELMs. By controlling flow characteristics and chemical gradients using these microfluidic networks, we demonstrate that we can enable a stable culture in a cerebral organoid system with the potential to engineer neural complexity in them. The integration of electrodes into the platform allows for long-term (15 days to 2 months) three-dimensional electrophysiology studies as the organoids develop around these electrodes. This innovative system holds promise for broad applications in ELM biosensors, organoid intelligence (OI), and developing other macro-scale organoid, bacteria, and tissue culture models to monitor biological threats, investigate toxicology, understand disease progression, and drug testing.

Acknowledgements (Optional): We acknowledge support from NSF EFMA-2318093 and JHU-SURPASS.