A Novel 3D-Bioprinting Technology of Orderly Extruded Multi-Materials via Photopolymerization

As a 3D bioprinting technique, digital light processing (DLP) has become popular due to its capability to provide high-throughput and high-resolution constructs with precise chemical and biological factor distributions. However, despite the advancements in DLP technology, several hurdles remain, including phototoxicity, extensive printing time, and the limited portfolio of biocompatible/photo-cross-linkable materials. Recently, few works have attended to resolve some of these issues. However, state-of-the-art techniques bear on complex imaging processing, require highly skilled personnel, and operate with non-biocompatible/photo-cross-linkable materials. Additionally, they are not yet capable of multi-layer and multi-material printing of biocompatible/photo-cross-linkable materials to fabricate physiologically relevant cell-laden structures. Herein, a novel DLP-based 3D-bioprinting technology called photopolymerization of orderly extruded multi-materials (POEM), is proposed, developed, and fully characterized. The utility of the POEM technique for rapid and high-resolution 3D-printing of multi-material, multi-layer, and cell-laden structures is demonstrated. The printed configurations show high cell viability (approximate to 80%) and metabolic activity for more than 5 days. As a study model, a 3D-structure representing the esophagus is also successfully printed and characterized. It is envisioned that the reported light-based POEM technique here enables the fabrication of 3D-cell-laden structures in a multi-material and multi-layer printing manner in biocompatible/photo-cross-linkable materials essential to construct complex heterogeneous tissues/organs.