A statistical study on nanoparticle movements in a microfluidic channel

[Interference of CTPS gene promotes toosendanin-induced apoptosis of human gastric cancer MKN-45 cells]

OBJECTIVE

To investigate the effect of interference of CTPS gene on toosendanin-induced apoptosis of gastric cancer MKN-45 cells.

METHODS

Bioinformatic analysis was used to analyze CTPS gene expression in human gastric cancer tissues and the overall survival of gastric cancer patients with high CTPS gene expression. Human gastric cancer MKN-45 cells were transfected with a short hairpin interfering RNA targeting CTPS gene, and 48 h later, qRT-PCR and Western blotting were used to detect cellular expression CTPS at both the mRNA and protein levels. MKN-45 cells with CTPS knockdown were treated with 80 nmol/L toosendanin for 48 h, and the cell viability was assessed with MTT assay; the cell morphology was observed using laser confocal microscope, and the expression of γH2AX was detected with immunofluorescence assay.

RESULTS

Bioinformatic analysis suggested that CTPS was highly expressed in human gastric cancer tissues, and gastric cancer patients with high CTPS gene expression had a shorter overall survival. MKN-45 cells transfected with Sh-CTPS interference vector showed significantly lowered cell survival rate (P < 0.01) with obvious cell shrinkage, irregular morphology, typical apoptotic changes, and increased cell apoptosis rate (P < 0.05). Treatment of the transfected cells with 80 nmol/L toosendanin for 48 h resulted in further reduction of the cell survival rate (P < 0.001), and the cells showed an increased apoptotic rate (P < 0.05) with appearance of apoptotic bodies.

CONCLUSION

Interference of CTPS gene can promote TSN-induced apoptosis of gastric cancer MKN-45 cells.

INTEGRATED 3D MULTI-PHYSICAL SIMULATION OF A MICROFLUIDIC SYSTEM USING FINITE ELEMENT ANALYSIS

Microfluidics technology has emerged as an attractive approach in physics, chemistry and biomedical science by providing increased analytical accuracy, sensitivity and efficiency in minimized systems. Numerical simulation can improve theoretical understanding, reduce prototyping consumption, and speed up development. In this paper, we setup a 3D model of an integrated microfluidic system and study the multi-physical dynamics of the system via the finite element method (FEM). The fluid–structure interaction (FSI) of fluid and an immobilized single cell within the cell trapping component, and the on-chip thermodynamics have been analyzed. The velocity magnitude and streamline of flow field, the distribution of von Mises stress and Tresca stress on the FSI interface have been studied. In addition, the on-chip heat transfer performance and temperature distribution in the heating zone have been evaluated and analyzed respectively. The presented approach is capable of optimizing microfluidic design, and revealing the complicated mechanism of multi-physical fields. Therefore, it holds the potential for improving microfluidics application in fundamental research and clinical settings.