Sharif Digital Repository

Nowadays, we are witnesses of deaths caused by cancer in large statistical amounts. Vast number of investigations are conducted for anticancer drug evaluation on human and animal cells using traditional two-dimensional and three-dimensional culturing platforms. However, most of them are not successful due to the lack of in-vivo relevant microenvironment in these platforms. One of the best cancer in-vitro cultures is the tumor spheroid which is a spherical cellular aggregation. By culturing these tumor spheroids in a microfluidic chip, it is possible to mimic the in-vivo microenvironment elements such as nutrient and metabolite gradients. Here we present a microfluidic device fabricated using... 

Particle separation has a variety of applications in biology, chemistry and industry. Among them, circulating tumor cells (CTCs) separation has drawn significant attention to itself due to its high impact on both cancer diagnosis and therapeutics. In recent years, there has been growing interest in using inertial microfluidics to separate micro/nano particles based on their sizes. This technique offers label-free, high throughput, and efficient separation and can be easily fabricated. However, further improvements are needed for potential clinical applications. In this study, a novel inertial separation technique using spiral microchannel with stair-like cross section is introduced. The... 

A complete understanding of high-intensity focused ultrasound-induced temperature changes in tissue requires insight into all potential mechanisms for heat deposition. Applications of therapeutic ultrasound often utilize acoustic pressures capable of producing cavitation activity. Recognizing the ability of bubbles to transfer acoustic energy into heat generation, a study of the role bubbles play in tissue hyperthermia becomes necessary. These bubbles are typically less than 50μm.
This dissertation examines the contribution of bubbles and their motion to an enhanced eating effect observed in a tissue-mimicking phantom. A series of experiments established a lationship between bubble... 

Circulating tumor cells (CTCs) isolation from a blood sample has an important value in cancer research and its treatment. Microfluidics provides a great potential for target cell separation from biological samples by using different physical principles. Among the microfluidic cell separation methods, the inertial microfluidic devices are advantageous in handling samples for point-of-care diagnostics due to their simple structure, fast, label-free and low-cost characteristics. In this thesis, first, we designed and investigated the application of a symmetric serpentine inertial microfluidic device for the separation of CTCs from whole blood. For this purpose, numerical modeling was performed...