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J. Stampfl, C. Heller, M. Schwentenwein, F. Varga, R. Liska:
"Biocompatible and biodegradeable photopolymers for lithography based solid freeform fabrication";
Talk: European Polymer Congress 2009, Graz; 07-12-2009 - 07-17-2009; in: "Book of Abstracts", F. Stelzer (ed.); (2009), 208.

The fabrication of geometrically well defined 3-dimensional scaffolds offering good cell adhesion is still an important topic in tissue engineering. One approach to manufacture these 3D-scaffolds is based on solid freeform fabrication (SFF). For this work, lithographic SFF-methods were evaluated regarding their suitability for fabricating cellular scaffolds. Among the examined methods are dynamic-mask processes, laser micro-stereolithography (see Figure 1) and two-photon-lithography. Due to the accessible resolutions of down to 0.5 μm lithographic techniques allow the fabrication of cellular structures for a number of applications in biomedical engineering. In order to find suitable materials the biocompatibility, determined by cell adhesion and cell proliferation of osteoblast-like cells, the photo reactivity, mechanical properties and cytotoxicity of several commercially available acrylate based monomers and polymers have been tested.

Despite the high rate of polymerization and the easy accessibility of a large number of monomers, the main drawback of these acrylate containing resins is the high cytotoxicity of residual unreacted acrylate groups. Therefore a completely new class of photoreactive monomers based on vinyl ester, vinyl carbonates and vinyl carbamates were synthesized. These materials turned out to show lower cytotoxicity by a factor of at least 100 compared to similar acrylates. The biocompatibility and mechanical properties of the vinyl ester polymers were evaluated, indicating the suitability of this new class of bio-photopolymers for a number of applications in tissue engineering. Furthermore, biodegradeability of these polymers can be easily tuned over a wide range.

Project Head Jürgen Stampfl:
Materialien für die 3D-Strukturierung mit 2-Photonen-Absorption