Surface Engineering for Long-Term Culturing of Mesenchymal Stem Cell Microarrays

Abstract

The cell microarray format can recreate a multitude of cell microenvironments on a single chip using only minimal amounts of reagent. In this study, we describe surface modifications to passivate cell microarrays, aiming to adapt the platform to the study of stem cell behavior over long-term culture periods. Functionalization of glass slides with (3-glycidyloxypropyl) trimethoxysilane enabled covalent anchoring of extracellular matrix proteins on microscale spots printed by a robotic contact printer. Subsequently, the surface was passivated by bovine serum albumin (BSA) or poly(ethylene glycol)bisamine (A-PEG) with molecular weights of 3000, 6000, and 10 000 Da. Cloud-point conditions for A-PEG grafting were attained that were compatible with protein deposition. Passivation strategies were assessed by culturing mesenchymal stem cells on the microarray platform. While both BSA and A-PEG passivation initially blocked cell adhesion between the printed spots, only A-PEG grafting was able to maintain cell pattern integrity over the entire culture period of 3 weeks.

Targeted drug delivery using genetically engineered diatom biosilica

“…Microarrays of HR1K Burkitt's lymphoma cells (B cells) and Jurkat cells (T cells) were generated by capturing the cells on microarray surfaces that display spots of immobilized anti-CD45 antibody ( Supplementary Fig. 2) [26][27][28] . It is noteworthy that both cell types express the antigen CD45.…”

“…We used anti-CD20 antibody, because it targets a highly expressed cell surface marker of B cells, CD20 (ref. 26). The cell-targeting ability of GB1-biosilica frustules labelled with anti-CD20 antibody was confirmed by their binding to immobilized Burkitt's lymphoma B cells in microarray experiments but not Jurkat T cells, which lack the CD20 marker, indicating that the adhesion of the functionalized biosilica to the cells resulted from specific binding to cell surface proteins.…”

Synergistic influence of collagen I and BMP 2 drives osteogenic differentiation of mesenchymal stem cells: A cell microarray analysis

“…After washing slides with Milli-Q water and drying with compressed nitrogen, the samples were dip-coated in a 10% solution of the epoxy silane (3-glycidyloxypropyl) trimethoxysilane (GOPTMS) (Sigma Aldrich) in dry toluene at room temperature for 30 min [3,33]. Excessive GOPTMS was removed by rinsing with dry toluene subsequently, samples were dried in a stream of dry nitrogen gas.…”

“…PBS was adjusted to pH 5 with glacial acetic acid to prevent gelling and precipitation of collagen and to increase the solubility of the lyophilised BMP 2. Glycerol was added to each protein solution at final concentration of 2% [3,34]. Proteins were spotted under conditions of 65% humidity and 11°C.…”

“…Together, these developments have driven the fabrication of miniaturised bioassay platforms compatible with long-term tissue culture, and thus suitable for the investigation of stem cell differentiation [1,2]. In this study, we use the protein microarray format to investigate the effect of surface-immobilised proteins on osteogenic differentiation of mesenchymal stem cells (MSCs) [3]. The regulation of MSC differentiation via biomaterial surfaces would translate into advances in regenerative medicine [4][5][6].…”