ABSTRACT
The study of intercellular signalling networks requires organotypic microscale systems that facilitate the culture, conditioning and manipulation of cells. Here, we describe a reconfigurable microfluidic cell-culture system that facilitates the assembly of three-dimensional tissue models by stacking layers that contain preconditioned microenvironments. By using principles of open and suspended microfluidics, the Stacks system is easily assembled or disassembled to provide spatial and temporal manoeuvrability in two-dimensional and three-dimensional assays of multiple cell types, enabling the modelling of sequential paracrine-signalling events, such as tumour-cell-mediated differentiation of macrophages and macrophage-facilitated angiogenesis. We used Stacks to recapitulate the in vivo observation that different prostate cancer tissues polarize macrophages with distinct gene-expression profiles of pro-inflammatory and anti-inflammatory cytokines. Stacks also enabled us to show that these two types of macrophages signal distinctly to endothelial cells, leading to blood vessels with different morphologies. Our proof-of-concept experiments exemplify how Stacks can efficiently model multicellular interactions and highlight the importance of spatiotemporal specificity in intercellular signalling.
Subject(s)
Cell Culture Techniques/methods , Microfluidic Analytical Techniques/methods , Microfluidics/methods , Signal Transduction , Spatio-Temporal Analysis , Cytokines/metabolism , Endothelial Cells , Humans , Macrophages , Microfluidic Analytical Techniques/instrumentation , Microfluidics/instrumentation , Transcriptome , Tumor MicroenvironmentABSTRACT
This tutorial review offers protocols, tips, insight, and considerations for practitioners interested in using micromilling to create microfluidic devices. The objective is to provide a potential user with information to guide them on whether micromilling would fill a specific need within their overall fabrication strategy. Comparisons are made between micromilling and other common fabrication methods for plastics in terms of technical capabilities and cost. The main discussion focuses on "how-to" aspects of micromilling, to enable a user to select proper equipment and tools, and obtain usable microfluidic parts with minimal start-up time and effort. The supplementary information provides more extensive discussion on CNC mill setup, alignment, and programming. We aim to reach an audience with minimal prior experience in milling, but with strong interests in fabrication of microfluidic devices.
