Synthesis of a biomimetic medical polymer

© Fraunhofer IAP
Figure 1: (a) Synthesis route to obtain urethane acrylates for 3D printing: without the use of toxic isocyanates, mono- and difunctionalized individual components can be synthesized for photoresins, which can be converted into photopolymers as reactive solvents (or as crosslinkers) using photobased 3D printing. (b) Synthesis route for the preparation of NIPU.

The pericardium surrounds the heart and consists of an elastic yet mechanically extremely stable material. Due to its unique properties, autologous or processed pericardium of animal origin has long been used in cardiac surgery as a reinforcing and sealing material, e.g. to close septal defects or in the construction of commercially available biological heart valves. In long-term use, calcification and hardening of the material has been observed. This explains, for example, the limited durability of biological heart valve prostheses.The aim of this project is to research a polymer that is able to replicate the demanding mechanical properties of the natural pericardium as closely as possible, is equally biocompatible and is biostable indefinitely in long-term use. The non-linear mechanical behavior of the natural pericardium is not inherent in most polymer materials. The PolyKARD project is therefore attempting to ensure that these materials retain their mechanical behavior by structuring them during the manufacturing process. Electrospinning and 3D printing are used for this purpose.

Figure 2: The photocurable urethane resins were processed into an artificial heart shell using digital light processing (DLP) on a newly developed 3D printer. (Source: YOE)


1.  Guanxing Kuang; Hadi Bakhshi; Wolfdietrich Meyer Urethane-Acrylate-Based Photo-Inks for Digital Light Processing of Flexible Materials. Journal of Polymer Research JPOL-D-22-01699, doi:submitted.

2.  Bakhshi, H.; Kuang, G.; Wieland, F.; Meyer, W. Photo-Curing Kinetics of 3D-Printing Photo-Inks Based on Urethane-Acrylates. Polymers 2022, 14, 2974, doi:10.3390/polym14152974.

3.  Singh, N.; Bakhshi, H.; Meyer, W. Developing Non-Isocyanate Urethane-Methacrylate Photo-Monomers for 3D Printing Application. RSC Adv. 2020, 10, 44103–44110, doi:10.1039/D0RA06388F.

4.  Visser, D.; Bakhshi, H.; Rogg, K.; Fuhrmann, E.; Wieland, F.; Schenke-Layland, K.; Meyer, W.; Hartmann, H. Green Chemistry for Biomimetic Materials: Synthesis and Electrospinning of High-Molecular-Weight Polycarbonate-Based Nonisocyanate Polyurethanes. ACS Omega 2022, doi:10.1021/acsomega.2c03731.



Dr. Wolfdietrich Meyer,

Dr. Hadi Bakhshi,

Fraunhofer IAP