Instruct: Identify the main category of Biorxiv papers based on the titles and abstracts
Query: In situ photopatterning of cell laden biomaterials for spatially organized 3D cell cultures in a microfluidic chip Micropatterning techniques for 3D cell cultures enable the recreation of tissue-level structures, but their combination with well-defined, microscale fluidic systems for perfusion remains challenging. To address this technological gap, we developed a user-friendly in-situ micropatterning protocol that integrates photolithography of crosslinkable, cell-laden hydrogels with a simple microfluidic housing, and tested the impact of crosslinking chemistry on stability and spatial resolution. Working with gelatin functionalized with photo-crosslinkable moieties, we found that inclusion of cells at high densities ([&ge;] 107/mL) during crosslinking did not impede thiol-norbornene gelation, but decreased the storage moduli of methacryloyl hydrogels. Hydrogel composition and light dose were selected to match the storage moduli of soft tissues. The cell-laden precursor solution was flowed into a microfluidic chamber and exposed to 405 nm light through a photomask to generate the desired pattern. The on-chip 3D cultures were self-standing, and the designs were interchangeable by simply swapping out the photomask. Thiol-ene hydrogels yielded highly accurate feature sizes from 100 - 900 m in diameter, whereas methacryloyl hydrogels yielded slightly enlarged features. Furthermore, only thiol-ene hydrogels were mechanically stable under perfusion overnight. Repeated patterning readily generated multi-region cultures, either separately or adjacent, including non-linear boundaries that are challenging to obtain on-chip. As a proof-of-principle, primary human T cells, were patterned on-chip with high regional specificity. Viability remained high (> 85%) after overnight culture with constant perfusion. We envision that this technology will enable researchers to pattern 3D cultures under fluidic control in biomimetic geometries that were previously difficult to obtain.
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The categories of this paper are: biophysics
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The categories of this paper are: microbiology
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The categories of this paper are: cognition
3
The categories of this paper are: evolutionary
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The categories of this paper are: scientific
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The categories of this paper are: paleontology
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The categories of this paper are: biology
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The categories of this paper are: systems
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The categories of this paper are: pathology
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The categories of this paper are: and
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The categories of this paper are: genetics
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The categories of this paper are: pharmacology
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The categories of this paper are: ecology
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The categories of this paper are: cancer
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The categories of this paper are: animal
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The categories of this paper are: developmental