Bioluminescence imaging on-chip platforms for non-invasive high-content bioimaging

Organ-on-chip systems require advanced monitoring tools to track cellular behavior over time. Conventional fluorescence methods often suffer from background interference or phototoxicity during long-term observation. This gap motivated the search for alternative optical sensing strategies. Bioluminescence imaging offers a non-invasive way to visualize biological processes within miniaturized environments. Prior research has shown that light-emitting enzymes can provide sensitive readouts in various biological contexts. However, integrating these sensors into microfluidic architectures remains a significant technical challenge. No prior work had resolved the specific requirements for combining these imaging modalities on-chip. That uncertainty drove the development of the platform described in this report.

The researchers aimed to integrate and optimize bioluminescence imaging within microfluidic platforms for non-invasive biological monitoring. Current organ-on-chip models often lack the ability to perform continuous, high-content imaging without causing cellular damage. This limitation hinders the broader adoption of these advanced in vitro systems in research. The team sought to overcome the drawbacks associated with conventional fluorescence-based detection methods. By incorporating light-emitting enzymes, they intended to provide a more sensitive and stable imaging modality. The study addresses the need for real-time, in-situ observation of cells cultured in three-dimensional hydrogels. They specifically focused on establishing optimal conditions for detecting signals at single-cell resolution. This work was motivated by the desire to improve the utility of miniaturized organ models for long-term studies.

The researchers engineered HEK293T-GFP cells to express the NanoLuc luciferase enzyme constitutively. These cells were subsequently embedded within three-dimensional hydrogels to simulate an extracellular matrix environment. A custom microfluidic device was designed to support continuous perfusion of the cell culture. The team utilized a dual-color microscopy setup to capture both light-emitting and fluorescent signals. Imaging was performed at single-cell resolution to assess the sensitivity of the platform. Furimazine was introduced into the system to trigger the light-emitting reaction. The investigators monitored the signal output starting twenty minutes after the substrate was added. This review approach focuses on the integration and optimization of these components for high-content analysis.

The platform achieved successful detection of bioluminescent signals at single-cell resolution within the microfluidic device. Agarose hydrogels exhibited a five-fold higher signal-to-noise ratio for bioluminescence compared to fluorescence. All tested hydrogel types supported the imaging of light-emitting cells under active perfusion conditions. The researchers observed that the bioluminescent output remained stable twenty minutes post-substrate injection. This approach allowed for the simultaneous visualization of multiple biological readouts in a non-invasive manner. The data confirm that the integration of this enzyme system is compatible with standard microfluidic architectures. These findings demonstrate that bioluminescence provides a clearer signal than traditional fluorescent markers in these environments. The results validate the feasibility of using this method for continuous monitoring of organ-on-chip models.

The authors demonstrate that bioluminescence imaging serves as a viable alternative to fluorescence for microfluidic applications. Their data suggest that this approach yields superior signal-to-noise ratios in hydrogel environments. The findings indicate that single-cell resolution is achievable under perfusion conditions. This work highlights the potential for continuous, non-invasive monitoring of multiple biological reporters simultaneously. The researchers propose that their integrated platform facilitates more robust data collection from organ-on-chip models. They conclude that light-emitting biosensors provide a highly desirable tool for future in vitro studies. The study confirms that substrate delivery and perfusion are compatible with high-content imaging requirements. These results provide a foundation for expanding the use of bioluminescent reporters in complex tissue engineering.