Highly accurate rendering of the external and internal geometry of bone tissue engineering scaffolds affects fit at the defect site, loading of internal pore spaces with cells, bioreactor-delivered nutrient and growth factor circulation, and scaffold resorption. It may be necessary to render resorbable polymer scaffolds with 50 µm or better accuracy to achieve these goals. This level of accuracy is available using Continuous Digital Light Processing (cDLP) which utilizes a DLP® (Texas Instruments, Dallas, TX) chip. One such additive manufacturing device is the envisionTEC (Ferndale, MI) Perfactory®. To use cDLP we integrate a photo-crosslinkable polymer, a photo-initiator, and a biocompatible dye. The dye attenuates light, thereby limiting the depth of polymerization. In this study we fabricated scaffolds using the well-studied resorbable polymer, poly(propylene fumarate) (PPF), titanium dioxide (TiO₂) as a dye, Irgacure® 819 (BASF [Ciba], Florham Park, NJ) as an initiator, and diethyl fumarate as a solvent to control viscosity.

高度精确地渲染骨组织工程支架的外部和内部几何形状会影响缺陷部位的配合、内部孔隙空间的细胞负载、生物反应器输送的营养和生长因子循环以及支架吸收。为了实现这些目标，可能需要以 50 µm 或更高的精度呈现可吸收聚合物支架。使用连续数字光处理 (cDLP) 可获得这种精度水平，该处理采用 DLP®（德克萨斯州达拉斯市德州仪器）芯片。一种这样的增材制造设备是 envisionTEC (Ferndale, MI) Perfactory®。为了使用 cDLP，我们集成了可光交联的聚合物、光引发剂和生物相容性染料。染料会衰减光，从而限制聚合深度。在这项研究中，我们使用经过充分研究的可吸收聚合物制造了支架，₂ ) 作为染料，Irgacure® 819 (BASF [Ciba], Florham Park, NJ) 作为引发剂，富马酸二乙酯作为溶剂来控制粘度。