The construction of three-dimensional micro-fluidic scaffolds of biodegradable polymers by solvent vapor based bonding of micro-molded layers.

It is increasingly important to control cell growth into and within artificial scaffolds. Tissues such as skin, blood vessels, and cartilage have multi-layer structures with different cells in each layer. With the aid of micro-fabrication technology, a novel scaffolding method for biodegradable polymers such as polylactic acid (PLA), polyglycolic acid (PGA), and the copolymers poly(lactide-co-glycolide)(PLGA), was developed to construct three-dimensional multi-layer micro-fluidic tissue scaffolds. The method emphasizes micro-fluidic interconnections between layers within the scaffolds and maintenance of high-resolution geometries during the bonding process for the creation of multi-layered scaffolds. Micro-holes (10-100 microm), micro-channels, and micro-cavities were all created by micro-molding. Solvent-vapor based bonding of micro-molded layers preserved 20 microm sized structures. Sample scaffolds were constructed for purposes such as channel-directed cell growth and size-based cell sorting. Further extension of these techniques to create a micro-vascular network within or between layers is possible. Culturing of human coronary artery endothelial cells (HCAECs) on the sample scaffolds demonstrated the biocompatibility of the developed process and the strong influence of high-resolution micro-geometries on HCAEC growth.