Fibre-based 3D implants from regenerated silk fibroin for intervertebral disc regeneration II

• Applicant: Dr. Michael Wöltje
• Subject Area: Biomaterials
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 437213841

In the first phase of the project, a process was successfully developed that makes it possible to develop new types of fibres from regenerated silk in a continuous spinning process. In addition, the structure of the intervertebral disc was completely reproduced in textiles for the first time. For this purpose, an inner structure made of an isotropic, porous fleece was developed and connected to an outer, ring-shaped, multi-layer reinforcing structure made of anisotropic, flat, lamellar layers, which were produced using embroidery technology from unidirectionally positioned silk fibers with alternating fibre orientation. This textile structure of silk fibers, which mimics the structure of the human intervertebral disc, showed in cell culture experiments that it is possible to develop artificial disc tissue with a cell density and cell size similar to that of the healthy human IVD. In addition, the tissue-specific morphology of the silk scaffold influenced the differentiation potential of the cultured MSCs. Based on the results of the first funding phase, the spinning process will first be evaluated in order to determine specific spinning parameters with which the fiber properties can be adapted to different requirements in terms of elasticity, tensile strength and fiber fineness. Furthermore, a method for functionalizing the silk fibers during the spinning process is to be developed in order to avoid costly subsequent functionalization of the textile structures. In addition, the textile reproduction of the intervertebral disc is to be further developed in order to reproduce the shock-absorbing properties of the intervertebral disc in a biomimetic way. Simulation-based three-dimensional structures produced by fiber-based additive manufacturing (FAM), a textile 3D printing technique, are combined with hydrogels. The resulting fiber-reinforced hydrogels are then systematically examined in various bovine ex vivo models under physiological stress. This is done in combination with growth factors and cells (MSCs and NP-specific progenitor cells). These project results will form the basis for evaluating the potential of complex fiber based 3D structures made from silk fibers in the context of spinal disc regeneration. Analysis of the results of these studies will allow an overall assessment of the relevance and effectiveness of these specific structures in disc regeneration.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Partner Organisation: Schweizerischer Nationalfonds (SNF)
• Cooperation Partner: Professor Dr. Ben Gantenbein