Advanced Bioactive Stent Grafts Based on Physicochemical Surface Properties: A Journey Through Biocompatibility and Manufacturability in Cardiovascular Product Development

The continuous enhancement of medical implants' biocompatibility and performance remains critical in biomedical research. This thesis focuses on improving stent grafts to treat aortic aneurysms by modifying expanded polytetrafluoroethylene (ePTFE) surfaces to enhance cell-material interactions. Plasma surface modification techniques were employed to optimize smooth muscle cell (SMC) adhesion and growth, which is crucial for vascular integrity and graft integration. Wettability gradients on ePTFE surfaces improved SMC proliferation and elongation, and these enhancements remained effective after industrial processing and aging tests.

While in vitro studies provided insight into cellular responses, they did not fully replicate physiological conditions. Animal studies confirmed the safety of plasma-modified stent grafts but also highlighted model limitations, emphasizing the need for further refinement. Additionally, porcine SMCs were shown to reliably predict human SMC responses, strengthening their role as a preclinical model.

Beyond stent grafts, the research extended into tissue engineering by developing porous poly(trimethylene carbonate) (PTMC) scaffolds. Various fabrication techniques were assessed to optimize porosity, a key factor in tissue-engineered models.

This thesis underscores the importance of integrating safety, manufacturability, and scalability into biomaterial development to ensure successful clinical translation. By leveraging high-throughput screening platforms and reliable preclinical models, the work addresses key challenges in biomaterial modification. The findings provide a foundation for developing safer, more effective stent grafts and other biomaterials-based medical devices, aligning with regulatory standards and clinical needs.