Collagen Surfaces Modified with Photo-Cleavable Polyethylene Glycol-Lipid Support Versatile Single-Cell Arrays of Both Non-adherent and Adherent Cells

Abstract

Cell patterning on photo-responsive materials are a promising tool for preparing unique single-cell arrays. However, most conventional single-cell arrays on such smart materials can be applied only to adherent cells and limit cellular functions such as extension and migration within the patterned adhesive surfaces. In this study, a versatile single cell array that works with both non-adherent and adherent cells was constructed using a photo-cleavable polyethylene glycol (PEG)-lipid/collagen surface. On this single-cell array, cells behaved similar to their native functions without limitation from the patterned surface. Furthermore, quantitative imaging analyses of cellular motility and morphological changes were performed in a high-throughput manner.

Microfluidic preparation of anchored cell membrane sheets for in vitro analyses and manipulation of the cytoplasmic face

“…Quantitative and exhaustive single-cell analyses can provide new and accurate insights that would be masked by the intrinsic heterogeneity of a cell population 28 . Use of the photo-responsive lipidation reagent 2 29 , 30 enabled construction of an array of cell membrane sheets, at a single cell level (Fig. 7a ).…”

Lipid tethering of breast tumor cells enables real-time imaging of free-floating cell dynamics and drug response

“…In this method, no cellular adhesive properties are necessary because the interaction of the cell membrane with the lipid results in cell tethering. Lipids have previously been used to immobilize cells [ 32 , 34 ]; here we have advanced this idea to create a simple system for studying McTNs on free-floating tumor cells. This approach eliminates the need for solvents, patterning, designed topographies, or antibodies used in other recent studies aimed at promoting adhesion of CTCs.…”

“…While cells were immobilized on the substrate, they remained free-floating owing to the cytophobic nature of the initial PEM coating. There was some loss of tethered cells as a function of the number of washes, but it is likely these interactions can be strengthened by incorporation of cross-linkable lipids [ 32 , 34 , 42 , 43 ]. We also observed a difference in the tethering efficiency as a function of cell line, with MCF-7 breast cancer cells exhibiting better tethering compared to MDA-MB-436 cells.…”

“…To enable this new ability, we identified three design features that would allow prolonged, real-time imaging and drug screening of McTNs on live tumor cells in a free-floating state: 1) optically-clear coatings to support imaging, 2) ability to control microfluidic flow over cells and 3) simple, low-energy manufacturing process. Past studies have demonstrated the utility of PEMs for tuning cell adhesion by varying polymer composition or through addition of lipids, RGD sequences, or other binding moieties [ 29 – 34 ]. Thus we leveraged PEMs to design a platform to immobilize live, detached tumor cells on microfluidic devices.…”

Separation and Analysis of Adherent and Non-Adherent Cancer Cells Using a Single-Cell Microarray Chip

“…Although these cell microarray systems efficiently performed high-throughput screening and analysis for biomaterials and anticancer drugs, a single-cell-based assay and retrieval seemed to be impossible using these microarray format. In another report, a chemical-trapping single cell array was developed to efficiently separate single cells using a photo-cleavable poly-ethylene glycol (PEG)-lipid [ 13 ]. The single cell array system achieved a single-cell-based assay, but it has difficulty retrieving chemical-trapped single-cells and there is a possibility of inducing chemical stress in trapped cells.…”