Three-dimensional printing of stem cell-laden hydrogels submerged in a hydrophobic high-density fluid

Abstract

Over the last decade, bioprinting technologies have begun providing important tissue engineering strategies for regenerative medicine and organ transplantation. The major drawback of past approaches has been poor or inadequate material-printing device and substrate combinations, as well as the relatively small size of the printed construct. Here, we hypothesise that cell-laden hydrogels can be printed when submerged in perfluorotributylamine (C(12)F(27)N), a hydrophobic high-density fluid, and that these cells placed within three-dimensional constructs remain viable allowing for cell proliferation and production of extracellular matrix. Human mesenchymal stem cells and MG-63 cells were encapsulated into agarose hydrogels, and subsequently printed in high aspect ratio in three dimensional structures that were supported in high density fluorocarbon. Three-dimensional structures with various shapes and sizes were manufactured and remained stable for more than six months. Live/dead and DAPI stainings showed viable cells 24 h after the printing process, as well as after 21 days in culture. Histological and immunohistochemical analyses after 14 and 21 days revealed viable cells with marked matrix production and signs of proliferation. The compressive strength values of the printed gels consequently increased during the two weeks in culture, revealing encouraging results for future applications in regenerative medicine.

Bioprinting: Uncovering the Utility Layer-By-Layer

“…Current bioprinting methods such as inkjet and laserinduced forward transfer often damage the cells [39] and have not yet been used to successfully produce large 3D structures [40]. Extrusion-based bioprinting is ideally suited to the fabrication of large tissue constructs.…”

“…Extrusion-based bioprinting is ideally suited to the fabrication of large tissue constructs. For example, in 2013 Campos et al printed into a high-density hydrophobic fluid, which allowed an almost unlimited number of printed layers, resulting in reproducible and high fidelity structures [40]. Extrusion systems are also the most cost-effective bioprinters, and accordingly, academic institutions are increasingly using extrusion bioprinting technology in tissue engineering research [41].…”

3D bioprinting of cell-laden hydrogels for advanced tissue engineering

“…While the technology of bioprinting itself has been the focus of research for the past 13 years [3][4][5][6][7] and will continue to be for years to come, e.g. technical, biological, and material related advances, the first signs of its evolution towards a tissue engineering tool with preclinical relevance can be observed today.…”

Modelling of the gelation process of biopolymers using the phase‐field method

“…For example, the agarose, alginate hydrogels, are chosen as bioink material for the 3D bioprinting. In the 3D bioprinting technology presented in [1], the prepared agarose gel is firstly sterilised at high temperature (120 • C), and then cooled down to the temperature of 37…”