Fabrication of PLGA scaffolds using soft lithography and microsyringe deposition

Construction of biodegradable, three-dimensional scaffolds for tissue engineering has been previously described using a variety of molding and rapid prototyping techniques. In this study, we report and compare two methods for fabricating poly(DL-lactide-co-glycolide) (PLGA) scaffolds with feature sizes of approximately 10-30 microm. The first technique, the pressure assisted microsyringe, is based on the use of a microsyringe that utilizes a computer-controlled, three-axis micropositioner, which allows the control of motor speeds and position. A PLGA solution is deposited from the needle of a syringe by the application of a constant pressure of 20-300 mm Hg, resulting in a controlled polymer deposition. The second technique is based on 'soft lithographic' approaches that utilize a poly(dimethylsiloxane) mold. Three variations of the second technique are presented: polymer casting, microfluidic perfusion, and spin coating. Polymer concentration, solvent composition, and mold dimensions influenced the resulting scaffolds as evaluated by light and electron microscopy. As a proof-of-concept for scaffold utility in tissue engineering applications, multilayer structures were formed by thermal lamination, and scaffolds were rendered porous by particulate leaching. These simple methods for forming PLGA scaffolds with microscale features may serve as useful tools to explore structure/function relationships in tissue engineering.