Microfabricated platform for studying stem cell fates

Abstract

Platforms that allow parallel, quantitative analysis of single cells will be integral to realizing the potential of postgenomic biology. In stem cell biology, the study of clonal stem cells in multiwell formats is currently both inefficient and time-consuming. Thus, to investigate low-frequency events of interest, large sample sizes must be interrogated. We report a simple, versatile, and efficient micropatterned arraying system conducive to the culture and dynamic monitoring of stem cell proliferation. This platform enables: 1) parallel, automated, long-term ( approximately days to weeks), live-cell microscopy of single cells in culture; 2) tracking of individual cell fates over time (proliferation, apoptosis); and 3) correlation of differentiated progeny with founder clones. To achieve these goals, we used microfabrication techniques to create an array of approximately 10,000 microwells on a glass coverslip. The dimensions of the wells are tunable, ranging from 20 to >500 microm in diameter and 10-500 microm in height. The microarray can be coated with adhesive proteins and is integrated into a culture chamber that permits rapid (approximately min), addressable monitoring of each well using a standard programmable microscope stage. All cells share the same media (including paracrine survival signals), as opposed to cells in multiwell formats. The incorporation of a coverslip as a substrate also renders the platform compatible with conventional, high-magnification light and fluorescent microscopy. We validated this approach by analyzing the proliferation dynamics of a heterogeneous adult rat neural stem cell population. Using this platform, one can further interrogate the response of distinct stem cell subpopulations to microenvironmental cues (mitogens, cell-cell interactions, and cell-extracellular matrix interactions) that govern their behavior. In the future, the platform may also be adapted for the study of other cell types by tailoring the surface coatings, microwell dimensions, and culture environment, thereby enabling parallel investigation of many distinct cellular responses.

Single cell trapping and DNA damage analysis using microwell arrays

“…Spatial registration of cells in a defined array obviates these problems and allows spatial encoding of multiple experimental conditions on the same slide, and cell spacing can be tuned to maximize the number of conditions per slide. Several methods currently exist for patterning cells, including dielectrophoresis (27), hydrostatic trapping (28), and microwell cell traps (29)(30)(31). Of these methods, only microwells capture cells passively, eliminating the need for external energy sources and introducing minimal external stress on cells.…”

Heterogeneous Differentiation of Human Mesenchymal Stem Cells in Response to Extended Culture in Extracellular Matrices

“…To address the second hurdle, microfluidic systems and flow cytometry systems capable of probing deep within three-dimensional tissues in a high throughput manner are being developed. 17,[36][37][38] That ECM components can drive heterologous differentiation of stem cells signals a great opportunity for emerging fields of regenerative medicine. One could envision biomaterial and synthetic constructs tailored with specific ECMderived peptides to induce lineage-specific differentiation.…”

Microfluidics-based systems biology

“…Isolated single cell and cell pair experimentation have been demonstrated; however, Chin et al 50 developed a massively high-throughput single cell array that maintained paracrine signaling throughout experimentation. The microfabricated array contained approximately 10 000 microwells and the investigators were able to track over 3 000 individual rat neural stem cells.…”