Membrane ibride come materiali innovativi per applicazioni biomedicali

Cardiovascular diseases (CVDs) are the leading global cause of death, currently affecting approximately 17.9 million people worldwide. As life expectancy continues to rise, this number is expected to increase even further. One of the primary therapeutic approaches for CVDs involves replacing damaged tissues and organs such as blood vessels and heart valves with grafts made from synthetic or chemically treated biological materials. In cases of heart failure, an alternative to heart transplantation is the use of mechanical circulatory support devices, such as total artificial hearts (TAHs), which are essential for patients requiring biventricular support. However, a significant limitation of these devices is the imperfect hemocompatibility of the materials in contact with blood. The potential thrombogenicity of these surfaces can lead to blood clot formation, necessitating lifelong anticoagulant and/or antiplatelet therapies, which increase the risk of bleeding complications. The aim of the project carried out over the past three years was to develop and characterize a new biomaterial intended for biomedical applications, including vascular grafts, prosthetic heart valves, and the inner surface of ventricular chambers for a total artificial heart under development at the University of Padua, in collaboration with Lodz University of Technology (Poland). This novel biomaterial must ensure a high degree of hemocompatibility, as it is created by coupling decellularized biological materials (bovine or porcine pericardia) with a commercially available polycarbonate urethane (Chronoflex AR and Chronoflex ARLT). The biological component, particularly the decellularized tissue, forms the blood-contacting surface, improving hemocompatibility, while the synthetic polymer provides mechanical resistance. The new biomaterial is classified as a hybrid material. In this thesis, the development and characterization steps of this new material are presented. A novel decellularization protocol, called Tergicol, was developed to obtain acellular matrices from porcine and bovine pericardia. The protocol was evaluated for its effectiveness in removing cellular content and eliminating the α-Gal antigen, while preserving the tissue’s protein structure. Mechanical behavior, sterilization effectiveness, and potential cytotoxicity were also assessed using human fibroblasts. The results demonstrated that the Tergicol protocol successfully produces a sterile, decellularized scaffold suitable for the research objectives. After decellularization, the biological tissues were coupled with the synthetic polymer to create four hybrid materials from different tissues and different polymer formulations. These materials were characterized in terms of their chemical, physical, and mechanical properties. Additionally, sterilization, cytotoxicity, and biocompatibility were tested both in vitro and in vivo. The analyses revealed that the materials possess appropriate mechanical characteristics and good biocompatibility, integrating well with the host organism without evoking any adverse reaction. The best-performing material, that is decellularized porcine pericardium coupled with Chronoflex AR, was selected for further development. Finally, the chosen hybrid material was used to create a hybrid conduit intended for use as a vascular substitute. It was characterized from both chemical and mechanical standpoints, revealing that the elastic properties of the material are primarily dictated by the polymer, while the viscous properties are dominated by the decellularized biological tissue. In conclusion, the proposed hybrid material is suitable for blood-contacting surfaces in cardiovascular devices, offering a promising solution for future clinical applications.