3D multicellular spheroids quickly emerged as in vitro models because they represent the vivo tumor environment better than standard 2D cell cultures. However, with current microscopy technologies, it is difficult to visualize individual cells deeper layers of samples mainly limited light penetration and scattering. To overcome this problem several optical clearing methods have been proposed bu...

Spheroids are widely used in vitro 3D multicellular model systems that mimic complex physiological microenvironments of tissues. As different cell types vary deformability and adhesion, the choice (heterogeneous) composition will define overall spheroid mechanics, including their viscoelasticity effective surface tension. These mechanical parameters directly influence sorting possibly invasion ...

This paper presents a multicellular spheroid chip capable of forming and extracting three-dimensional (3D) spheroids using removable cell trapping barriers. Compared to the conventional macro-scale spheroid formation methods, including spinning, hanging-drop, and liquid-overlay methods, the recent micro-scale spheroid chips have the advantage of forming smaller spheroids with better uniformity....

@ 0///)// ! 115 $8$68 8 145 "!36"$6768""6! ######63$"8 (BLOCKIN#AA+9+++AAAABC######63$"8* When you leave your homeland, you leave a part of your heart there. It needs many big hearts to repair it. I have been blessed to have so many warm hearted people around me to complete my lost piece of heart. To my beloved husband Pasha and my precious son Attila List of enclosed papers This thesis is base...

Collective cell motion is observed in a wide range of biological processes. In tumors, physiological gradients of nutrients, growth factors, or even oxygen give rise to gradients of proliferation. We show using fluorescently labeled particles that these gradients drive a velocity field resulting in a cellular flow in multicellular spheroids. Under mechanical stress, the cellular flow is drastic...

Heterogeneity within tumour cell populations is commonly observed in most cancers. However, its impact on metastatic dissemination, one of the primary determinants of the disease prognosis, remains poorly understood. Working with a simplified numerical model of tumour spheroids, we investigated the impact of mechanical heterogeneity on the onset of tumour invasion into surrounding tissues. Our ...