Poly-urethane vascular graft

Macrophages are critical players in host response, remodeling and degradation. However, an assessment tool to evaluate the degradation of biodegradable materials in a more physiological environment is still needed. Dr Marjan Enayati (Medical University Vienna) has developed an in vitro model based on monocyte-derived macrophage cell culture that allows long-term analysis of degradation and mechanical properties of polyurethanes (TPU). Professor José Luis Toca-Herrera and Dr Jagoba Iturri from Institute for Biophysics (Department of Nanobiotechnology) contributed to the detection of surface defects in the fibrous structure of these scaffolds as degradation proceeds, mediated by activated macrophages both in vitro and in vivo, by employing Atomic Force Microscopy and Scanning Electron Microscopy techniques.


A cell culture model using monocyte-derived primary macrophages has been established to study the degradation, macro- / micro- mechanical behavior and inflammatory behavior of a new designed, biodegradable thermoplastic polyurethane (TPU) scaffold, over an extended period of time in vitro. For in vivo studies, the scaffolds were implanted subcutaneously in a rat model for up to 36 weeks.

The results have shown that TPU scaffolds supported the attachment and migration of macrophages throughout the three-dimensional matrix. Scaffold degradation could be detected in localized areas, emphasizing the role of adherent macrophages in scaffold degradation. Weight loss, molecular weight and biomechanical strength reduction were evident in the presence of the primary macrophage cells. In addition, TPU favored the switch from initial pro-inflammatory response of macrophages to an anti-inflammatory response over time both in vitro and in vivo.

Read more in: Journal of the Mechanical Behavior of Biomedical Materials, 3 September 2020 (https://doi.org/10.1016/j.jmbbm.2020.104077)

"Assessment of a long-term in vitro model to characterize the mechanical behavior and macrophage-mediated degradation of a novel, degradable, electrospun poly-urethane vascular graft"

Marjan Enayati, Sarah Puchhammer, Jagoba Iturri, Christian Grasl, Christoph Kaun, Stefan Baudis, Ingrid Walter, Heinrich Schima, Robert Liska, Johann Wojta, José LuisToca-Herrera, Bruno K. Podesser, Helga Bergmeister