Fabrication of 3D biocompatible/biodegradable micro-scaffolds using dynamic mask projection microstereolithography

Microstereolithography (mu SL) technology can fabricate three-dimensional (3D) tissue engineered scaffolds with controlled biochemical and mechanical micro-architectures. A mu SL system for tissue engineering was developed using a Digital Micromirror Device (DMD (TM)) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for crosslinking the photoreactive polymer solution. The mu SL system was designed with x-y resolution of similar to 2 mu m and a vertical (z) resolution of similar to 1 mu m. To demonstrate the use of mu SL in tissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weight of similar to 1200 Da. The viscosity of the PPF was reduced to similar to 150 cP (at 50 degrees C) by mixing with diethyl fumarate (DEF) in the ratio of 7:3 (w/w). Finally, similar to 2% (w/w) of bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide (BAPO) was added to the solution to serve as a photoinitiator. Cure depth experiments were performed to determine the curing characteristics of the synthesized PPF, and the resulting system and prepolymer were used to construct a 3D porous scaffold with interconnected pores of similar to 100 mu m. Scanning electron microscopy (SEM), and micro-computed tomography (mu CT) images of the micro-architecture illustrate that the developed mu SL system is a promising technology for producing biodegradable and biocompatible 3D micro-scaffolds with fully interconnected pores. (C) 2009 Elsevier B.V. All rights reserved.