Thierry Colin | PubMed Health

PubMed2006

Viscosimeter on a microfluidic chip.

In this work, a viscosimeter implemented on a microfluidic chip is presented. The physical principle of this system is to use laminar parallel flows in a microfluidic channel. The fluid to be studied flows side by side with a reference fluid of known viscosity. By using optical microscopy, the shape of the interface between both fluids can be determined. Knowing the flow rates of the two liquids and the geometrical features of the channel, the mean shear rate sustained by the fluid and its viscosity can thus be computed. Accurate and precise measurements of the viscosity as a function of the shear rate can be made using less than 300 microL of fluid. Several complex fluids are tested with viscosities ranging from 10(-)(3) to 70 Pa.s.

Journal Article↗

PubMed2006

A multiscale mathematical model of cancer, and its use in analyzing irradiation therapies.

BACKGROUND: Radiotherapy outcomes are usually predicted using the Linear Quadratic model. However, this model does not integrate complex features of tumor growth, in particular cell cycle regulation. METHODS: In this paper, we propose a multiscale model of cancer growth based on the genetic and molecular features of the evolution of colorectal cancer. The model includes key genes, cellular kinetics, tissue dynamics, macroscopic tumor evolution and radiosensitivity dependence on the cell cycle phase. We investigate the role of gene-dependent cell cycle regulation in the response of tumors to therapeutic irradiation protocols. RESULTS: Simulation results emphasize the importance of tumor tissue features and the need to consider regulating factors such as hypoxia, as well as tumor geometry and tissue dynamics, in predicting and improving radiotherapeutic efficacy. CONCLUSION: This model provides insight into the coupling of complex biological processes, which leads to a better understanding of oncogenesis. This will hopefully lead to improved irradiation therapy.

Cell Cycle↗