Combining fabrication and surface modification techniques to develop cell-laden microfluidic devices

Micro-Electro-Mechanical Systems (MEMS) technologies illustrate the potential for many applications in the field of tissue engineering, regenerative medicine, and life sciences. The fabrication of tissue models integrates the multidisciplinary field of life sciences and engineering. Presently, monolayer cell cultures are frequently used to investigate potential anti-cancer agents. These monolayer cultures give limited feedback on the effects of the micro-environment. A micro-environment, which mimics that of the target tissue, will eliminate the limitations of the traditional mainstays of tissue research. The fabrication of such micro-environment requires a thorough investigation of the actual target organ and/or tissue. Microfabrication techniques are utilized to develop microfluidic channels for continuous nutrition supply to cells inside a micro-environment. The ability of cells to build tissues and maintain tissue-specific functions depends on the interaction between cells and the extracellular matrix (ECM). Three-dimensional tissue platforms are rapidly becoming the method of choice for quantification of the heterogeneity of cell populations for many diagnostic and drug therapy applications. Microfluidic sensors and the integration of sensors with microfluidic systems are often described as miniature versions of their macro-scale counterparts. This technology presents unique advantages for handling costly and difficult-to-obtain samples and reagents as a typical system requires between 100 nL to 10microL of working fluid. The fabrication of a fully functional cell-based biosensor utilizes both biological patterning and microfabrication techniques. SU-8 is a popular photosensitive epoxy-based polymer in MEMS. The patterning of bare SU-8 alone does not provide the appropriate ECM necessary to develop microsystems for biological applications. Manipulating the chemical composition of SU-8 will enhance the biological compatibility, giving the fabricated constructs the appropriate ECM needed to promote a functional tissue array. The objective of this research is to investigate the integration of maskless fabrication, direct cell deposition, and surface modification techniques to engineer cell-laden microfluidics. This thesis presents advances in additive manufacturing techniques, the utilization of plasma chemistry to enhance surface functionalization, and manipulation of photo-polymerization to investigate new approaches to assemble cell-laden microfluidics.