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

Microstereolithography (μSL) technology can fabricate three-dimensional (3D) tissue engineered scaffolds with controlled biochemical and mechanical micro-architectures. A μSL system for tissue engineering was developed using a Digital Micromirror Device (DMD™) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for crosslinking the photoreactive polymer solution. The μSL system was designed with x–y resolution of ∼2 μm and a vertical (z) resolution of ∼1 μm. To demonstrate the use of μSL in tissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weight of ∼1200 Da. The viscosity of the PPF was reduced to ∼150 cP (at 50 °C) by mixing with diethyl fumarate (DEF) in the ratio of 7:3 (w/w). Finally, ∼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 ∼100 μm. Scanning electron microscopy (SEM), and micro-computed tomography (μCT) images of the micro-architecture illustrate that the developed μSL system is a promising technology for producing biodegradable and biocompatible 3D micro-scaffolds with fully interconnected pores.