Non-stationary mass transfer in gel systems with graphene oxide as applied to 3d-bioprinting technologies

The pattern of diffusion front propagation in pure agarose hydrogels as well as with the addition of graphene oxide was compared by the methods of moving boundaries and optical sensing, and the mass-transfer properties of the gel systems were measured. It was found that graphene oxide has high surface activity, becomes part of the mesh structure of the gel, increasing its porosity and thus affecting the diffusion rate and efficiency. In addition, graphene oxide contributes to the ordering of the gel structure or reduces light scattering within the gel. The combination of hydrogels with graphene oxide enables the creation of systems with controllable optical properties, which in turn opens up new opportunities for improving 3D-bioprinting technologies. Based on the random walk method, a numerical model is proposed that is well suited to describe the structures of hydrogels with graphene oxide. This model will help to determine the quality of materials in 3D-bioprinting technologies in terms of nutrient delivery efficiency for living microorganisms located inside the gel. The comparison of experimental data and numerical modeling demonstrated a good agreement between them.