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A. Wilke, S. Baudis, H. Wilhelm, H. Bergmeister, F. Nehl, R. Liska, J. Stampfl:
"Additive Manufactured Photoelastomers as Tailor-made Biomaterials for Vascular Tissue Restoration";
Talk: Euromat 2011, Montpellier; 09-12-2011 - 09-15-2011; in: "Euromat 2011 Montpellier", (2011), 0264-1-1.

A predominant part of morbidity and mortality in industrial countries can be attributed to deceases of the cardiovascular system.
Our aim is to design new biocompatible materials for the application of narrow blood vessel replacement like coronary bypasses. The approach is to use elastic photopolymers for artificial vascular grafts. By means of additive manufacturing technologies (AMTs) like digital light processing (DLP) very complex structures are realizable. Hence AMTs offer the possibility to create cellular structures within the artificial grafts that might favor the ingrowth of new tissue.
Photoelastomers can be tailored by variation of the ratio of reactive diluents and crosslinker and the addition of thiols to the monomer formulation. The best composition of the monomer system of ethylene glycol bis¬thio¬glycolate, 2-hydroxyethyl acrylate and urethane diacrylate was adjusted for the additive manufacturing process DLP regarding the photoinitiator- and absorber concentration to approach even more to the mechanical properties of natural blood vessels1.
Mechanical properties as well as biodegradability of materials designated for small caliber blood vessel replacement materials are of crucial importance 2.
For analysis of the mechanical properties a conventional tensile machine has been applied to characterize the materials regarding elastic modulus (E), the tensile strength (σM) and the elongation at break (εB). Additionally, a special suture tear test has been developed as the vascular grafts are sewed to the natural blood vessels. Hence to the critical forces at the junction site, the mechanical properties of the synthetic materials have to gain a sufficient suture tear resistance (RT) which approaches that of the native blood vessels.
Degradation tests were performed in phosphate buffered saline (PBS) at elevated temperatures.
The optimized photoelastomers are in good accordance with natural blood vessels concerning their mechanical properties, show good biocompatibility in in-vitro tests with human umbilical vein endothelial cells, degrade similar to PLA and were successfully manufactured with DLP-AMT.

http://publik.tuwien.ac.at/files/PubDat_201903.pdf