Microchip for subcellular mechanics study in living cells

This paper reports a PDMS microchip for subcellular mechanics study, which consists of micrometer scale polymeric pillars on a plain substrate for cellular force measurement. The chip reported here differs from those proposed in previous work in that a flexible polymer microfabrication technique was applied for manufacturing the polymeric microstructures with various aspect ratios. This allows for the measurement of a range of forces encountered at the subcellular level. The microchip was integrated with a perfusion chamber to allow for precise control of the extracellular environment, thus facilitating cellular mechanics studies under various physiological conditions. A biocompatibility test was carried out using two types of mammalian cells (fibroblasts and cardiac myocytes). The results show satisfactory abundances of both types of cells, with no adverse affect of the PDMS microchip on cell viability. A proof-of-concept force measurement was performed in single contracting cardiac myocytes. The force distribution with a subcellular resolution conforms to the physiologic behavior of cardiac myoctes, indicating the potential application of the reported microchip in subcellular mechanics study.