Microfluidic device featuring micro-constrained channels for multi-parametric assessment of cellular biomechanics and high-precision mechanical phenotyping of gastric cells.

BACKGROUND: Cellular biomechanics plays a significant role in the regulation of cellular physiological and pathological processes. In recent years, multiple methods have been developed to evaluate cellular biomechanics, such as atomic force microscopy (AFM), micropipette aspiration, and magnetic tweezers. However, most of these methods only focus on a single parameter and cannot automate the process at a high-efficiency level. A novel microfluidic method is necessary to achieve the simultaneous multi-parametric measurement of cellular biomechanics and high-precision cellular mechanical phenotyping at high throughput. RESULTS: To tackle the issue concerning the low-throughput and cellular single-parameter evaluation, we designed and fabricated a microfluidic chip featuring multiple micro-constrained channels structure, providing a simultaneous multi-parametric assessment of cellular biomechanics, including elastic modulus, recovery capability, and deformability. We compared the biomechanical properties of normal human gastric mucosal epithelial cells (GES-1) and human gastric cancer cells (AGS and MKN-45) by the chip. Results demonstrated that the elastic modulus of GES-1, AGS, and MKN-45 cells decreased sequentially, which was the opposite of their invasiveness and metastasis potential, suggesting the inverse correlation between cellular elastic modulus and malignancy. Meanwhile, the recovery capability and deformability of GES-1, AGS, and MKN-45 cells increased sequentially, demonstrating the positive correlation between cellular deformability and malignancy. Furthermore, multiple parameters were used to distinguish gastric cancer cells from normal gastric cells via machine learning. An accuracy of over 94.8% for identifying gastric cancer cells was achieved. SIGNIFICANCE: This study provides a deep insight into the biophysical mechanism of gastric cancer metastasis at the single-cell level and possesses great potential to function as a valuable tool for single-cell analysis, thereby facilitating high-precision and high-throughput discrimination of cellular phenotypes that are not easily discernible through single-marker analysis.

A microfluidic platform integrating dynamic cell culture and dielectrophoretic manipulation for in situ assessment of endothelial cell mechanics.

The function of vascular endothelial cells (ECs) within the complex vascular microenvironment is typically modulated by biochemical cues, cell-cell interactions, and fluid shear stress. These regulatory factors play a crucial role in determining cell mechanical properties, such as elastic and shear moduli, which are important parameters for assessing cell status. However, most studies on the measurement of cell mechanical properties have been conducted in vitro, which is labor-intensive and time-consuming. Notably, many physiological factors are lacking in Petri dish culture compared with in vivo conditions, leading to inaccurate results and poor clinical relevance. Herein, we developed a multi-layer microfluidic chip that integrates dynamic cell culture, manipulation and dielectrophoretic in situ measurement of mechanical properties. Furthermore, we numerically and experimentally simulated the vascular microenvironment to investigate the effects of flow rate and tumor necrosis factor-alpha (TNF-α) on the Young's modulus of human umbilical vein endothelial cells (HUVECs). Results showed that greater fluid shear stress results in increased Young's modulus of HUVECs, suggesting the importance of hemodynamics in modulating the biomechanics of ECs. In contrast, TNF-α, an inflammation inducer, dramatically decreased HUVEC stiffness, demonstrating an adverse impact on the vascular endothelium. Blebbistatin, a cytoskeleton disruptor, significantly reduced the Young's modulus of HUVECs. In summary, the proposed vascular-mimetic dynamic culture and monitoring approach enables the physiological development of ECs in organ-on-a-chip microsystems for accurately and efficiently studying hemodynamics and pharmacological mechanisms underlying cardiovascular diseases.