Directing the Self-assembly of Tumour Spheroids by Bioprinting Cellular Heterogeneous Models within Alginate/Gelatin Hydrogels

Abstract

Human tumour progression is a dynamic process involving diverse biological and biochemical events such as genetic mutation and selection in addition to physical, chemical, and mechanical events occurring between cells and the tumour microenvironment. Using 3D bioprinting we have developed a method to embed MDA-MB-231 triple negative breast cancer cells, and IMR-90 fibroblast cells, within a cross-linked alginate/gelatin matrix at specific initial locations relative to each other. After 7 days of co-culture the MDA-MB-231 cells begin to form multicellular tumour spheroids (MCTS) that increase in size and frequency over time. After ~15 days the IMR-90 stromal fibroblast cells migrate through a non-cellularized region of the hydrogel matrix and infiltrate the MDA-MB-231 spheroids creating mixed MDA-MB-231/IMR-90 MCTS. This study provides a proof-of-concept that biomimetic in vitro tissue co-culture models bioprinted with both breast cancer cells and fibroblasts will result in MCTS that can be maintained for durations of several weeks.

A Custom Ultra-Low-Cost 3D Bioprinter Supports Cell Growth and Differentiation

“…On the other hand, they could produce less shear stress to the embedded cells as less extrusion pressure was required; this makes them desirable candidates for bioprinting delicate cells, such as pRGCs. Ultimately, such bioinks could have better shape fidelity results, if they were bioprinted in a support bath as previously described (Jiang et al, 2017). In our cell culture experiments, they were only bioprinted at a height of 3 layers, to minimize the spreading ratio and preserve the extrusion uniformity.…”

Native-mimicking in vitro microenvironment: an elusive and seductive future for tumor modeling and tissue engineering

“…With various modifications, alginate has also been applied in wound healing, cartilage repair, and bone regeneration. Alginate-based hydrogel, on the other hand, was used to form tumor spheroids in microfluidic culture systems in an attempt to mimic solid tumors [ 145 ]; to blend with other biocompatible biomaterials such as gelatin to make composite hydrogel and with tumor cells and TAFs for in vitro tumor models to study cell-cell interactions and mechanisms of tumorigenesis [ 146 ]; to mimic TME in 3D cultures for angiogenesis with the engagement of cancer cells, VEGF, and integrin [ 147 ].…”

Emulating Human Tissues and Organs: A Bioprinting Perspective Toward Personalized Medicine

“… 442 , 446 , 448 By using piston-assisted extrusion to deposit breast cancer cells and fibroblasts in precise locations separated by an acellular region, it was possible to investigate the formation of multicellular tumor spheroids and to evaluate fibroblast migration toward the tumor cells within alginate/gelatin hydrogels. 448 A different model used vat photopolymerization to fabricate a breast cancer model in coculture with bone stromal cells embedded within a gelMA matrix. When the two cell types were cultured together, increased proliferation and secretion of VEGF by breast cancer cells was observed 449 Similarly, the extrusion of a gelMA-based bioink containing glioblastoma cells and macrophages in distinct locations made it possible to identify possible paracrine and juxtacrine interactions between these cell types during tumor development 442 ( Figure 13 B).…”