Improvements in Microfabrication of Integrated Collagen Scaffolds Containing Embedded Microchannels Inside 3D Extracellular Matrix with 2D Basement Membrane Linings

Abstract

Collagen's biocompatibility, biodegradability, and cell-adhesive properties make it vital for developing biomimetic scaffolds in tissue engineering. This thesis enhances the microfabrication of collagen scaffolds with micro-conduits, mimicking the Extracellular Matrix (ECM). These scaffolds feature a 3D porous collagen sponge, mimicking the interstitial matrix, with embedded microchannels with varying widths (70-1000 μm) resembling veins and vessels and micropatterns, as well as a 2D collagen film lining the microchannel walls that mimic the basement membrane. Through soft lithography, freeze-drying, and contact printing, scaffolds with enclosed macrochannels in multiple layers were created and reinforced with composite effects of components and crosslinking. Characterization methods included microscopy, ImageJ analysis, optical profilometry, flow studies, and SEM imaging. Factors influencing scaffold flatness and achievable microchannel dimensions were investigated in a parametric study. Preliminary cultures evaluated scaffold viability for culturing mice brain tissue and studying various cell behaviors, including HEp2, HEp2D and HEK 293T cell lines. These scaffolds offer customizable physical characteristics for diverse tissue applications, facilitating blood vessel modeling, cell co-culture, and drug delivery studies.