Perfusion-based co-culture model system for bone tissue engineering

• DOI: 10.3934/bioeng.2020009
• Publication Date: 2020-05-31T21:38:06Z
• Authors: Stephen W. Sawyer; ; Kairui Zhang; Jason A. Horton; Pranav Soman
• Keywords: 0301 basic medicine; cell encapsulation; gelatin methacrylate; perfusion; endothelial cells; Article; bioreactor; 03 medical and health sciences; Chemical engineering; Medical technology; mineral formation; TP155-156; R855-855.5; TP248.13-248.65; Biotechnology

In this work, we report on a perfusion-based co-culture system that could be used for bone tissue engineering applications. The model system is created using a combination of Primary Human Umbilical Vein Endothelial Cells (HUVECs) and osteoblast-like Saos-2 cells encapsulated within a Gelatin Methacrylate (GelMA)-collagen hydrogel blend contained within 3D printed, perfusable constructs. The constructs contain dual channels, within a custom-built bioreactor, that were perfused with osteogenic media for up to two weeks in order to induce mineral deposition. Mineral deposition in constructs containing only HUVECs, only Saos-2 cells, or a combination thereof was quantified by microCT to determine if the combination of endothelial cells and bone-like cells increased mineral deposition. Histological and fluorescent staining was used to verify mineral deposition and cellular function both along and between the perfused channels. While there was not a quantifiable difference in the amount of mineral deposited in Saos-2 only versus Saos-2 plus HUVEC samples, the location of the deposited mineral differed dramatically between the groups and indicated that the addition of HUVECs within the GelMA matrix allowed Saos-2 cells, in diffusion limited regions of the construct, to deposit bone mineral. This work serves as a model on how to create perfusable bone tissue engineering constructs using a combination of 3D printing and cellular co-cultures.