High cell viability, biofunctionaly. good printing resolution and mechanically stable constructs are only a few of various challenging goals that must be addressed to apply biofabrication for tissue regeneration. Since 01.01.2018, a collaborative research centre, the SFB TRR 225, is working on the advanced development of the key elements of biofabrication in the medical sense. Synergizing transdisciplinary expertises in the fields of material science, engineering, biology and medicine, the collaborating partner institutes have established a complementary basis for the holistic research, which will be crucial to achieve progress in this complex field.

The Biopolymer Processing Group is involved with project A07 - Fiber-reinforced hydrogels, working together with Prof. Dr. Dirk Schubert (Institute of Polymer Materials, Friedrich-Alexander-University Erlangen-Nuremberg). The objective of this project is to apply fiber-reinforced composite bioinks to overcome the issues of cell-harming shear forces upon printing on the one side, and the lack of shape fidelity and mechanical stability of the resulting constructs on the other side. Incorporation of fiber fragments is hypothesized to provide aligned supportive structures for cells and simultaneously increase the volume of plug flow with reduced shear forces on the cells. Furthermore, shape fidelity and mechanical strength should be improved using mechanically stable filler materials. Recently, a method to produce polycaprolactone fiber fragments with controllable aspect ratios has been developed based on an electrospinning process approach. Homogeneous fiber dispersion in established hydrogels could be demonstrated and rheological studies on the impact of loading density and fiber length are ongoing.  To quantify these effects and systematically describe the resulting material characteristics, viscoelastic models are applied to fit the measured data and work towards advanced material understanding allowing predictability in the design of new bioinks with this transferable composite system.

Universität Bayreuth -