Speaker
Description
Musculoskeletal interface injuries, especially at the tendon-bone junctions, present a significant clinical challenge due to their limited ability to regenerate and the structural complexity of native tissues. Current treatment methods often do not restore biomechanical functionality, highlighting the need for advanced biomimetic scaffolds. Our goal is to engineer tissue-specific constructs using 3D printing technologies, focusing on the functional regeneration of tendon-bone interfaces. We focus on designing and fabricating gradient scaffolds that integrate both macro- and microscale features through additive manufacturing. Our emphasis is on developing innovative infill patterns and concave architectures that provide better cell adhesion and tissue development compared to convex structures [1] and enable tailored mechanical properties.
Our approach combines Fused Deposition Modelling (FDM) with Melt Electrowriting (MEW). MEW is a novel technique that enables highly precise deposition of polymer microfibers under the influence of an electric field. FDM is used to create stiffer scaffold regions that mimic the bone part of the interface, while softer and more flexible structures that imitate the tendon part are produced using MEW.
Concave structures based on small intersection angles and sinusoids were designed. Scaffolds were fabricated from polycaprolactone (PCL) using a multi-head tool (BioScaffolder 3.3, GeSiM). Optimisation of the printing parameters for both techniques was performed. Microstructural, mechanical and biological studies were performed for scaffolds with various fibre thicknesses, geometrical designs, and pore sizes. The tensile strength tests revealed significant differences between varying architectural designs, resulting from fibre density and inter-fibre distance variations. Also, the initial biological test model using primary human dermal fibroblasts revealed distinct cells' preference for concave structures. Enhanced cell bridging was linked to concavities that featured closer fibre connections. In contrast, in more distant fibre connections, cells preferentially aligned along the fibres.
Currently, we are investigating the performance of the tenocites on the gradient scaffolds. Additional data on cell adhesion, morphology, viability, migration, and distribution will provide valuable insights for future studies on the tendon-bone interface structure.
[1] M. Werner, S.B.G. Blanquer, S.P. Haimi, G. Korus, J.W.C. Dunlop, G.N. Duda, D.W. Grijpma, A. Petersen, Surface Curvature Differentially Regulates Stem Cell Migration and Differentiation via Altered Attachment Morphology and Nuclear Deformation, Advanced Science 4(2) (2017) 1600347.
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