Lab-On-A-Chip For Analysis Of Mono- And Co-Cultures Of Human Cell Lines

Despite of their broad use, most cell-based in vitro assays to date neglect that cell response and function in vitro are gravely influenced by their microenvironment. Microfluidics is an emerging technology that provides the means to develop physiologically relevant conditions highly needed for biologic assays by controlling the cellular microenvironment including geometry, liquid flow and surface chemistry. While microscopy can solely provide qualitative information, quantitative data is usually difficult to obtain but still crucial for in-depth understanding of biological processes. Advanced microfluidic systems with integrated biosensors, termed lab-on-a-chip devices, enable non-invasive and time-resolved analysis of dynamic cell responses. Therefore, the aim of this thesis was to address crucial aspects of bioengineering by combining microfluidics with integrated biosensing strategies, engineered biopolymer coatings, as well as two- and three-dimensional strategies for cultivation of single- as well as multi-cell populations. Three different microfluidic strategies have been fabricated, optimized, characterized and applied for in vitro cell cultures. Firstly, a molecular toolkit based on two-dimensional self-assembled bacterial surface layer proteins for generation of patterned co-cultures is presented. Secondly, optical light scattering detection and electric cell impedance sensing was combined in a single cell analysis platform for continuous non-invasive monitoring of cell numbers, cell morphology, as well as cell-to-cell and cell-to-surface interactions. Thirdly, a microfluidic strategy for dynamic co-culture of adipose-derived stem cells with human umbilical vein endothelial cells embedded within the context of a three-dimensional fibrin matrix was established to study the influence of accumulation and depletion of pro-angiogenic factors on vascular network formation. Finally, the main advances of the newly established microfluidic strategies are highlighted and based on the presented data, a general outlook over on-going research projects is given. Microfluidics, S-layer, micro-patterning, three-dimensional, cell co-cultures, biosensors