The last years have seen an increasing interest in the development of photo-polymerizable monomers providing low cytotoxicity and high thermo-mechanical properties in their cured state.1 This fact can mainly be explained by the rapid progress in UV based additive manufacturing technologies such as stereolithography, digital light processing or 3D ink-jet printing, which enables the fast, accurate and individual fabrication of biocompatible structures. In this context also the tissue compatibility of photopolymers has to be considered in particular for medical devices that are in direct contact with blood or bone.
In this contribution, the versatility of the thiol-yne photo-click reaction2 for the fabrication of biocompatible photopolymers is shown at the example of tailor-made alkyne and thiol monomers. For that purpose, commercially available acrylate monomers were modified using the carbon and oxa michael addition reaction to obtain multifunctional alkyne building blocks.
It turned out that these synthesized monomers offer curing rates similar to the acrylates, while providing much higher conversion and lower monomer cytotoxicity. This reaction leads to highly uniform polymeric networks exhibiting a sharp and defined thermal glass transition together with outstanding impact resistance, which makes these polymers interesting for challenging applications such as medical implants.3 Not only non-degradable, but also degradable monomers were designed, enabling the selective adjustment of the resorption behavior of the resulting polymers.4
The herein described monomer systems pave the way towards the individual fabrication of tissue compatible photopolymers with tunable thermo-mechanical properties and resorption behavior.
(1) Mautner, A.; Steinbauer, B.; Russmüller, G.; Lieber, R.; Koch, T.; Stampfl, J.; Liska, R. Designed Monomers and Polymers 2016, 19, 437.
(2) Lowe, A. B.; Hoyle, C. E.; Bowman, C. N. J. Mater. Chem. 2010, 20, 4745.
(3) Oesterreicher, A.; Gorsche, C.; Ayalur Karunakaran, S.; Moser, A.; Edler, M.; Pinter, G.; Schlögl, S.; Liska, R.; Griesser, T. Macromolecular Rapid Communications 2016, 37, 1701.
(4) Oesterreicher, A.; Wiener, J.; Roth, M.; Moser, A.; Gmeiner, R.; Edler, M.; Pinter, G.; Griesser, T. Polym. Chem. 2016, 7, 5169.