Deep learning unlocks label-free viability assessment of cancer spheroids in microfluidics.

Despite recent advances in cancer treatment, refining therapeutic agents remains a critical task for oncologists. Precise evaluation of drug effectiveness necessitates the use of 3D cell culture instead of traditional 2D monolayers. Microfluidic platforms have enabled high-throughput drug screening with 3D models, but current viability assays for 3D cancer spheroids have limitations in reliability and cytotoxicity. This study introduces a deep learning model for non-destructive, label-free viability estimation based on phase-contrast images, providing a cost-effective, high-throughput solution for continuous spheroid monitoring in microfluidics. Microfluidic technology facilitated the creation of a high-throughput cancer spheroid platform with approximately 12 000 spheroids per chip for drug screening. Validation involved tests with eight conventional chemotherapeutic drugs, revealing a strong correlation between viability assessed via LIVE/DEAD staining and phase-contrast morphology. Extending the model's application to novel compounds and cell lines not in the training dataset yielded promising results, implying the potential for a universal viability estimation model. Experiments with an alternative microscopy setup supported the model's transferability across different laboratories. Using this method, we also tracked the dynamic changes in spheroid viability during the course of drug administration. In summary, this research integrates a robust platform with high-throughput microfluidic cancer spheroid assays and deep learning-based viability estimation, with broad applicability to various cell lines, compounds, and research settings.

Bioeffects of Inhaled Nanoplastics on Neurons and Alteration of Animal Behaviors through Deposition in the Brain.

The potential toxicity of nanoplastics on plants has previously been illustrated, but whether nanoplastics could cause neurotoxicity, especially to higher animals, remains unclear. We now demonstrate that nanoplastics can be deposited in the brain via nasal inhalation, triggering neuron toxicity and altering the animal behavior. Polystyrene nanoparticles (PS-NPs) of PS-COOH and PS-NH2 are used as models for nanoplastics. We designed a microfluidic chip to evaluate the PS-NPs with different concentrations, surface ligands, and sizes to interact with neurons. Smaller PS-NPs can induce more cellular uptake than larger PS-NPs. PS-NPs with a size of 80 nm can reach and deposit in the brain of mice via aerosol inhalation. Mice inhaling PS-NPs exhibit fewer activities in comparison to those inhaling water droplets. An obvious neurotoxicity of the nanoplastics could be observed from the results of the inhibition of AChE activities. Our results show the potential significance of the physiochemical properties of organic nanoplastics on depositing in mammalian brains by nasal inhalation.