Development of new electroconductive biomaterial for cardiac application: MXene-Collagen. Physical, chemical and biological characterizations on films and scaffolds.

Heart diseases are the leading cause of death globally. Among them, the most common one is the myocardial infarction that occurs when in the coronary artery of the heart the blood flow decreases or stops. The heart cells, particularly cardiomyocytes, are very sensitive to oxygen deficiency and suddenly die. To minimize damages as quickly as possible, a wound-healing process begins, which includes: the proliferation and maturation of cardiac fibroblasts into myofibroblasts, the deposition of new extracellular matrix (ECM), and an increase in the content of type I and III collagen. All of these processes result in myocardial fibrosis and stiffness of heart tissue. Due to the inability of cardiomyocytes to proliferate, scar tissue will not become functional, and heart function will not be restored. As a result of the reduced capacity of the heart pump, heart failure can take place. There are currently no drugs or approaches that promote heart regeneration, and heart transplantation remains the only clinical option. However, due to a paucity of donors and the danger of rejection, this method has several limitations. New techniques for infarcted myocardial regeneration are being researched to overcome the limitations of transplantation. The aim of this thesis work is the development of a new electroconductive biomaterial suitable for cardiac applications, that involves the use of collagen and MXene (specifically Ti3C2Tx), an emerging class of 2D transitional metal carbides, that have appropriate mechanical, electroconductive and biocompatibility properties that can facilitate the replication of the myocardial environment. The work focused on the optimization of the blending process of collagen and MXene, exploiting gelatin as a dispersion agent, to obtain a homogeneous and colloidal solution. Films and scaffolds at different MXene concentrations were fabricated (15%, 30%, 45%, 60% and 75% w/w) and a number of physical, chemical and biological characterizations were carried out (i.e. electroconductive behaviour, stability, swelling, mechanical properties, Raman spectroscopy, Live-Dead assay, Alamar blue assay).