A three-dimensional microfabrication system for biodegradable polymers with high resolution and biocompatibility

Biodegradable polylactide polymers are already widely used in medicine. While further applications are eagerly awaited, progress has been impeded by a lack of appropriate processing methods. Our group attempted to construct a novel three-dimensional microfabrication system for the free processing of three-dimensional micro-level forms. The system processed the polymers with extremely high precision using a fine nozzle. An evaluation of one of the piled-up layers of the extruded lines revealed lateral and depth resolutions of 40 µm and 45 µm, respectively. Micro-pipes, micro-bends and micro-coil springs were fabricated in less than 15 min by stacking up melted polymers from a nozzle. A batch process was adopted for the supply of the materials in order to eliminate the use of toxic solvents, one of the necessary evils with earlier fabrication techniques. Microstructures fabricated by our system and by a conventional method were tested in tensile strength tests to compare the mechanical strengths. The biocompatibility of a newly fabricated structure was tested by cultivating a cell line (PC12) in a small poly(lactic acid) (PLA) vessel with a transparent base, then comparing the morphology and growth with those of the same PC12 line cultivated by a standard vessel.