An interfacial self-assembling bioink for the manufacturing of capillary-like structures with tuneable and anisotropic permeability

Self-assembling bioinks offer the possibility to biofabricate with molecular precision, hierarchical control, and biofunctionality. For this to become a reality with widespread impact, it is essential to engineer these ink systems ensuring reproducibility and providing suitable standardization. We have reported a self-assembling bioink based on disordered-to-ordered transitions of an elastin-like recombinamer (ELR) to co-assemble with graphene oxide (GO). Here, we establish reproducible processes, optimize printing parameters for its use as a bioink, describe new advantages that the self-assembling bioink can provide, and demonstrate how to fabricate novel structures with physiological relevance. We fabricate capillary-like structures with resolutions down to ~10 µm in diameter and ~2 µm thick tube walls and use both experimental and finite element analysis to characterize the printing conditions, underlying interfacial diffusion-reaction mechanism of assembly, printing fidelity, and material porosity and permeability. We demonstrate the capacity to modulate the pore size and tune the permeability of the resulting structures with and without human umbilical vascular endothelial cells (hUVECs). Finally, the potential of the ELR-GO bioink to enable supramolecular fabrication of biomimetic structures was demonstrated by printing tubes exhibiting walls with progressively different structure and permeability

FABRICATION AND CHARACTERIZATION OF A MICROFLUIDIC NETWORK MADE OF ELASTIN-LIKE POLYPEPTIDES (ELP) AND GRAPHENE OXIDE(GO)

Microfluidics refers to a set of technologies for the manipulation of small fluid volumes (mL) within artificially microsystems. Among the microfluidic systems, there are Organ-On-Chip (OOC), microfluidic devices for culturing living cells in continuously perfusion, with the aim of modelling the physiological functions of tissues and organs. OOC devices can be used not only to elucidate the mechanisms involved in the development of a blood vessel but also as experimental platforms for vascular disease models and drug screening. This thesis is focused on the fabrication of a microfluidic system using a group of materials called Elastin-Like Polypeptides (ELP). In particular, a material capable of self-assembling (ELK1) inside graphene oxide (GO) has been used. In order to achieve this objective, diffusivity at the membrane interface and biofabrication tests were carried out