Microfabricated polyester conical microwells for cell culture applications

Abstract

Over the past few years there has been a great deal of interest in reducing experimental systems to a lab-on-a-chip scale. There has been particular interest in conducting high-throughput screening studies using microscale devices, for example in stem cell research. Microwells have emerged as the structure of choice for such tests. Most manufacturing approaches for microwell fabrication are based on photolithography, soft lithography, and etching. However, some of these approaches require extensive equipment, lengthy fabrication process, and modifications to the existing microwell patterns are costly. Here we show a convenient, fast, and low-cost method for fabricating microwells for cell culture applications by laser ablation of a polyester film coated with silicone glue. Microwell diameter was controlled by adjusting the laser power and speed, and the well depth by stacking several layers of film. By using this setup, a device containing hundreds of microwells can be fabricated in a few minutes to analyze cell behavior. Murine embryonic stem cells and human hepatoblastoma cells were seeded in polyester microwells of different sizes and showed that after 9 days in culture cell aggregates were formed without a noticeable deleterious effect of the polyester film and glue. These results show that the polyester microwell platform may be useful for cell culture applications. The ease of fabrication adds to the appeal of this device as minimal technological skill and equipment is required.

Polyester μ-assay chip for stem cell studies

“…A mechanism for extraction of the cell aggregates from the individual microwells was not in place at this point, limiting our cell analysis in visual observation. These results match qualitatively the findings from previous research, 50 where mESCs were cultured under static conditions. However, in perfusion culture, the formed cell aggregates filled the microwells almost completely by day 5, which was 4 days earlier than in static culture.…”

“…We have previously shown that microwell platforms could be easily and quickly manufactured using laser ablation of sticky polyester films. 50 Furthermore, we demonstrated that this material could be used in cell experiments without deleterious effects on the cell viability. The polyester l-assay chip presented here combines microwells for cell storage and 3D culture with a network of microfluidic channels.…”

“…The individual platforms consisted of a microwell array laser ablated onto a polyester layer, as described elsewhere, 50 and glued onto a blank PDMS slab. Each microwell platform was kept inside a separate well on a 6-well plate and stored in a cell culture incubator.…”

“…Each glue layer was protected with a 50.8 lm thick polyester liner (Figure 1(a)). The well layer of the device was patterned by laser ablation of the polyester film, as described elsewhere, 50 in order to yield a 10 Â 10 array of 150 lm large circular microwells with a conical cross-section. The laser power chosen was 3.6 W and the printing speed was 22.9 cm/s.…”

Formation of size-controllable spheroids using gingiva-derived stem cells and concave microwells: Morphology and viability tests

“…Other materials, including polydimethylsiloxane and polyurethane, have been applied to create three-dimensional cultures using photolithography (6,7). Additionally, poly(ethylene glycol) diacrylate, polymethylmethacrylate, poly(N-isopropylacrylamide) and polyester have been applied for the culture platform, while bypassing lithography (8)(9)(10). A previous study proved that three-dimensional culture systems have demonstrated the importance of intercellular interactions in regulating stem cell self-renewal and differentiation (3).…”