Fabrication of Complex 3D Micro-Scale Scaffolds and Drug Delivery Devices using Dynamic Mask Projection Microstereolithography

摘要

Microstereolithography (μSL) technology can fabricate three-dimensional (3D) tissuernengineered scaffolds with controlled biochemical and mechanical micro-architectures. ArnμSL system for tissue engineering was developed using a Digital Micromirror Devicern(DMDTM) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm forrncrosslinking the photoreactive polymer solution. The μSL system was designed with x-yrnresolution of ～2 μm and a vertical (z) resolution of ～1 μm. To demonstrate the use of μSL inrntissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weightrnof ～1200 Da. The viscosity of the PPF was reduced to ～150 cP (at 50 ℃) by mixing withrndiethyl fumarate (DEF) in the ratio of 7:3 (w/w). Finally, ～2 % (w/w) of (bis(2,4,6-rntrimethylbenzoyl) phenylphosphine oxide (BAPO) was added to the solution to serve as arnphotoinitiator. Cure depth experiments were performed to determine the curingrncharacteristics of the synthesized PPF, and the resulting system and photopolymer were usedrnto construct a variety of 3D porous scaffolds with interconnected pores between 100 and 150rnμm and a micro-needle array with height of ~800 μm and individual tip diameters of ～20 μm.rnSEM and microscope images of the micro-architectures illustrate that the developed μSLrnsystem is a promising technology for producing biodegradable and biocompatiblernmicrostructures.