Molded polyethylene glycol microstructures for capturing cells within microfluidic channels

Abstract

The ability to control the deposition and location of adherent and non-adherent cells within microfluidic devices is beneficial for the development of micro-scale bioanalytical tools and high-throughput screening systems. Here, we introduce a simple technique to fabricate poly(ethylene glycol) (PEG) microstructures within microfluidic channels that can be used to dock cells within pre-defined locations. Microstructures of various shapes were used to capture and shear-protect cells despite medium flow in the channel. Using this approach, PEG microwells were fabricated either with exposed or non-exposed substrates. Proteins and cells adhered within microwells with exposed substrates, while non-exposed substrates prevented protein and cell adhesion (although the cells were captured inside the features). Furthermore, immobilized cells remained viable and were stained for cell surface receptors by sequential flow of antibodies and secondary fluorescent probes. With its unique strengths in utility and control, this approach is potentially beneficial for the development of cell-based analytical devices and microreactors that enable the capture and real-time analysis of cells within microchannels, irrespective of cell anchorage properties.

Production of Uniform 3D Microtumors in Hydrogel Microwell Arrays for Measurement of Viability, Morphology, and Signaling Pathway Activation

“…For covalent attachment of PEG hydrogel microwells to the glass slide, sodium hydroxide-treated glass slides were coated with 3-trimethoxysilyl polymethacrylate (TMSPMA). 23 Cell Culture All cells were cultured under sterile conditions and maintained in 5% CO 2 at 37°C in a humidified incubator. Cells were cultured in Dulbecco's modified Eagle's medium (DMEM) containing 10% Hyclone fetal bovine serum (FBS).…”

Integration column: microwell arrays for mammalian cell culture

“…40,56 These templates create low shear stress regions to enable docking of the cells inside the microwells and subsequently can be used to form cell aggregates. 57,58 Various parameters such as the size of the PEG macromers used to crosslink PEG microwell arrays can significantly influence the long-term response of EBs in these cultures. Specifically, in culture conditions in which the microwells were made from relatively hydrophobic lower molecular weight PEG, cells tended to stick to the entire surfaces, whereas in cultures made from more hydrophilic higher molecular weight PEG, it was possible to maintain the non-adherent features of these microwells much longer.…”

Exploitation of physical and chemical constraints for three-dimensional microtissue construction in microfluidics

“…The cells move along the flow and sediment into the microwells. Khademhosseini et al 46 developed polyethylene glycol ͑PEG͒ microstructures inside the microfluidic channels to trap both adherent and nonadherent cell types. NIH-3T3 fibroblasts and mouse embryonic stem cells ͑ES cells͒ were introduced into the channels and the flow is intermittently stopped, allowing the cells to settle in wells ͓Fig.…”