an-open-source-technology-platform-to-manufacture-hydrogel-based-3d

An Open Source Technology Platform to Manufacture Hydrogel-Based 3D Culture Models in an Automated and Standardized Fashion

Current mixing steps of viscous materials rely on repetitive and time-consuming tasks which are performed mainly manually in a low throughput mode. These ...

Queensland University of Technology

Skin is a critical organ that plays a crucial role in defending the internal organs of the body. For this reason, extensive work has gone into creating artificial models of the epidermis for in vitro skin toxicity tests. These tissue models, called reconstructed human epidermis (RhE), are used by researchers in the pharmaceutical, cosmetic, and environmental arenas to evaluate skin toxicity upon exposure to xenobiotics. Here, we present a label-free solution that leverages the use of the intelligent mobile lab for in vitro diagnostics (IMOLA-IVD), a noninvasive, sensor-based platform, to monitor the transepithelial electrical resistance (TEER) of RhE models and adherent cells cultured on porous membrane inserts. Murine fibroblasts cultured on polycarbonate membranes were first used as a test model to optimize procedures using a custom BioChip encapsulation design, as well as dual fluidic configurations, for continuous and automated perfusion of membrane-bound cultures. Extracellular acidification rate (EAR) and TEER of membrane-bound L929 cells were monitored. The developed protocol was then used to monitor the TEER of MatTek EpiDerm RhE models over a period of 48 hours. TEER and EAR measurements demonstrated that the designed system is capable of maintaining stable cultures on the chip, monitoring metabolic parameters, and revealing tissue breakdown over time.

Skin-on-a-Chip: Transepithelial Electrical Resistance and Extracellular Acidification Measurements through an Automated Air-Liquid Interface.

Melt electrowriting (MEW) combines the fundamental principles of electrospinning, a fibre forming technology, and 3D printing. The process, however, is highly complex and the quality of the fabricated structures strongly depends on the interplay of key printing parameter settings including processing temperature, applied voltage, collection speed, and applied pressure. These parameters act in unison, comprising the principal forces on the electrified jet: pushing the viscous polymer out of the nozzle and mechanically and electrostatically dragging it for deposition towards the collector. Although previous studies interpreted the underlying mechanism of electrospinning with polymer melts in a direct writing mode, contemporary devices used in laboratory environments lack the capability to collect large data reproducibly. Yet, a validated large data set is a condition sine qua non to design an in-process control system which allows to computer control the complexity of the MEW process. For this reason, we engineered an advanced automated MEW system with monitoring capabilities to specifically generate large, reproducible data volumes which allows the interpretation of complex process parameters. Additionally, the design of an innovative real-time MEW monitoring system identifies the main effects of the system parameters on the geometry of the fibre flight path. This enables, for the first time, the establishment of a comprehensive correlation between the input parameters and the geometry of a MEW jet. The study verifies the most stable process parameters for the highly reproducible fabrication of a medical-grade poly(ε-caprolactone) fibres and demonstrates how Printomics can be performed for the high throughput analysis of processing parameters for MEW.

Printomics: the high-throughput analysis of printing parameters applied to melt electrowriting.

While much progress has been accomplished in the development of physiologically relevant in vitro disease models, current manufacturing and characterisation workflows still rely on manual, time-consuming, and low-throughput processes, which are not efficient and prone to human errors. For these reasons adoption and, more importantly, reproducibility and validation of 3D in vitro disease models is rather low for fundamental and applied research concepts. This article argues in form of a perspective view that automation and high-throughput methodologies will play a vital role to act as a catalyst to accelerate the development and characterisation process for generations to come. Innovative engineering concepts are required to overcome current limitations of in vitro disease models and to foster the scientific rigour as well as the applied research potential.

In vitro disease models 4.0 via automation and high-throughput processing.

Microphysiometry is a powerful technique to study metabolic parameters and detect changes to external stimuli. However, applying this technique for automated label-free and real-time measurements within cell-laden three-dimensional (3D) cell culture constructs remains a challenge. Herein, we present an entirely automated microphysiometry setup that combines needle-type microsensors with motorized sample and sensor positioning systems inside a standard tissue-culture incubator. The setup records dissolved oxygen as a metabolic parameter along the -direction within cell-laden 3D constructs in a minimally invasive manner. The microphysiometry setup was applied to characterize the spatial oxygen distribution within thick cell-laden 3D constructs, study the time-dependent changes on the oxygen tension within 3D breast cancer models following a chemotherapeutic treatment, and identify kinetics and recovery effects after drug exposure over 5 weeks. Our data suggest that the microphysiometry setup enables highly reproducible measurements without human intervention, due to the high degree of automation and positional accuracy. The results demonstrate the applicability of the setup to provide valuable long-term insights into oxygenation within 3D models using minimally invasive, label-free, and entirely automated analysis methods.

Article	Year
Skin-on-a-Chip: Transepithelial Electrical Resistance and Extracellular Acidification Measurements through an Automated Air-Liquid Interface. Genes\| PubMed ID: 29466319	2018
Printomics: the high-throughput analysis of printing parameters applied to melt electrowriting. Biofabrication\| PubMed ID: 30616231	2019
In vitro disease models 4.0 via automation and high-throughput processing. Biofabrication\| PubMed ID: 31293247	2019
Automated 3D Microphysiometry Facilitates High-Content and Highly Reproducible Oxygen Measurements within 3D Cell Culture Models. ACS sensors\| PubMed ID: 33621068	2021

Sebastian Eggert

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