Developing Hybrid Hydrogels for Full-Scale Scaffold Fabrication Using Extrusion-Based Bioprinting Process

Abstract

Three-dimensional (3D) bioprinting is a technology that has the power to positively change the medical and pharmaceutical fields in a new and more intuitive way. The goal of this rapidly growing field is to recreate functional tissues, but the process requires the ability to achieve large full-scale scaffolds that replicate human organs. There are many challenges when attempting to print large scaffolds ensuring proper internal and external geometric fidelity that is also suitable for the living cells that undergo the printing process. In order to fabricate a larger and more structurally sound scaffold, higher material viscosities are necessary. This increase in viscosity comes with an increase in printing pressure, which can create unbearable shear stress and eventually damage cells, diminishing viability and proliferation. A set of biomaterial compositions with high structural integrity and shape fidelity that did not require harmful amounts of pressure for extrusion was identified by analyzing rheological, mechanical, and microstructural properties. Many different large-scale scaffolds maintaining geometric fidelity were fabricated with heights up to 3.0 cm and 74 layers using these hybrid hydrogels. This advancement can ensure precise internal and external geometries of full-scale functional tissue replicating scaffolds using 3D bio-printing processes that utilize pressures and materials safe for live cell viability and proliferation.