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M. Enayati, S. Puchhammer, J. Iturri, C. Grasl, C. Kaun, S. Baudis, I. Walter, H. Schima, R. Liska, J. Wojta, J. Toca-Herrera, B. Podesser, H. Bergmeister:
"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";
Journal of the Mechanical Behavior of Biomedical Materials, 112 (2020), 12; 735 - 749.

An assessment tool to evaluate the degradation of biodegradable materials in a more physiological environment is still needed. Macrophages are critical players in host response, remodeling and degradation. In this study, a cell culture model using monocyte-detived ptimary macrophages was established ro study the degradation, macro-/ micro-mechanical behavior and inflammat01y behavior of a new designed, biodegradable theimoplastic poly­urethane (TPU) scaffold, over an extended pe1iod of time in vitro. For in vivo study, the scaffolds were implanted subcutaneously in a rat model for up to 36 weeks. TPU scaffolds were fabricated via the electrospinning method. This technique provided a fibrous scaffold with an average fiber diameter of 1.39 ± 0. 76 µm and an average pore size of 7.5 ± 1.1 µm. The results showed 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 primaiy macrophage cells. TPU favored the switch fom initial pro-inflammato1y response of macrophages ro an anti-inflammat01y response over time both in vitro and in vivo. Expression of MMP-2 and MMP-9 (the key enzymes in tissue remodeling based on ECM modifications) was also evident in vitro and in vivo. This study showed that the primruy monocyte-derived cell culture model represents a promising tool to characterize the degradation, mechanical behavior as weil as biocompatibility of the scaffolds during an extended period of observation.

the degradation of biodegradable materials, a cell culture model, the degradation, macro-/ micro-mechanical behavior and inflammat01y behavior of a new designed, biodegradable theimoplastic poly­urethane (TPU), in vivo study

http://dx.doi.org/10.1016/j.jmbbm.2020.104077

https://www.sciencedirect.com/science/article/pii/S1751616120306263