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FDM bioprinter to promote mesenchymal stem cell chondrogenesis

Tissue and organ shortages are demanding issues that force more than 120,000 people in the United States to suffer while waiting for an available replacement donation. Tissue-engineered constructs utilizing polymer scaffolds are being investigated as viable substitutions to resolve this need. Fused deposition of a designed model is a novel 3D-printing fabrication method that can produce these scaffolds in a biologically supportive environment. Our project aims are two-fold: to modify an existing bioprinter design, and to produce cartilage by directing chondrogenesis from rat mesenchymal stem cells (rMSCs) on a printed scaffold. The bioprinting process consists of four phases: Phase I utilizes a software interface to thermally extrude a layer-by-layer filament of polycaprolactone, and guide a moveable stage to produce a pre-defined three-dimensional scaffold. During Phase II, the scaffold is aseptically prepared for cell deposition using ultraviolet irradiation. Phase III occurs within a novel environmental heating chamber, where rMSCs are dispensed onto the scaffold which is immersed in a collagen I solution to promote cell adhesion. Phase IV transfers the construct to the cell culturing station outside of the device chamber, where biochemical additives will be applied to promote cell differentiation and chondrocyte growth. The design will be evaluated based on in-vitro results from scaffold surface morphology, cell viability after deposition, and cartilage-specific biomarkers.