3D micro-organisation printing of mammalian cells to generate biological tissues

Gavin D M Jeffries,Shijun Xu,Christoffer Gyllensten,Vladimir Kirejev,Owe Orwar,Paul Karila,Lydia Moll,Tatsiana Lobovkina,Florian Tusseau,Avadhesh Kumar Singh

doi:10.1038/s41598-020-74191-w

Abstract

Significant strides have been made in the development of in vitro systems for disease modelling. However, the requirement of microenvironment control has placed limitations on the generation of relevant models. Herein, we present a biological tissue printing approach that employs open-volume microfluidics to position individual cells in complex 2D and 3D patterns, as well as in single cell arrays. The variety of bioprinted cell types employed, including skin epithelial (HaCaT), skin cancer (A431), liver cancer (Hep G2), and fibroblast (3T3-J2) cells, all of which exhibited excellent viability and survivability, allowing printed structures to rapidly develop into confluent tissues. To demonstrate a simple 2D oncology model, A431 and HaCaT cells were printed and grown into tissues. Furthermore, a basic skin model was established to probe drug response. 3D tissue formation was demonstrated by co-printing Hep G2 and 3T3-J2 cells onto an established fibroblast layer, the functionality of which was probed by measuring albumin production, and was found to be higher in comparison to both 2D and monoculture approaches. Bioprinting of primary cells was tested using acutely isolated primary rat dorsal root ganglia neurons, which survived and established processes. The presented technique offers a novel open-volume microfluidics approach to bioprint cells for the generation of biological tissues.

Highlights

Significant strides have been made in the development of in vitro systems for disease modelling
Our bioprinting approach utilises a recirculating fluid flow, generated at the tip of a free-standing microfluidic device[16,17], which we use as a printhead to achieve high-resolution printing
A photograph of a loaded printhead, where cell chambers were loaded with colored solutions for visualization purpose can be Scientific Reports | (2020) 10:19529 |

Summary

Introduction

Significant strides have been made in the development of in vitro systems for disease modelling. The variety of bioprinted cell types employed, including skin epithelial (HaCaT), skin cancer (A431), liver cancer (Hep G2), and fibroblast (3T3-J2) cells, all of which exhibited excellent viability and survivability, allowing printed structures to rapidly develop into confluent tissues. Taking into consideration the rationale outlined above, it is not surprising that there is a growing number of experimental approaches to building complex tissue-like structures These approaches can be generalised into three families; spontaneous self-assembly methods, cell patterning approaches, and bioprinting strategies. Spontaneous self-assembly methods such as organoids, multicellular cultures, as well as 3D culturing and co-culturing techniques, rely upon cell positioning to be guided by chemotactic means In this approach cell arrangement is largely stochastic in nature and little control is conveyed over the final

Methods

Results

Conclusion