An in vitro assessment of the responses of human dermal fibroblast seeded on 3D printed thermoplastic polyurethane scaffold

Tissue engineering is a multidisciplinary field is an interdisciplinary field for the design of biological substitutes that can improve, restore, and maintain tissue functions. Thermoplastic polyurethanes (TPUs) are linear polymers which are widely used for tissue engineering due to its flexibility in processing methods, biocompatibility and excellent mechanical properties. They are suitable materials for use in three-dimensional (3D) printing. Dermal fibroblasts are mesenchymal cells which play crucial roles in physiological tissue repair. The present study aimed to investigate the viability, proliferation, adhesion, and type IV collagen expression of human dermal fibroblasts (HDFs) seeded on 3D printed TPU scaffolds in vitro. HDFs were seeded on 3D TPU scaffolds or tissue culture polystyrene plates as control and cultured for 1, 3, 7, and 14 days. 3D TPU scaffolds were prepared using a custom made fused deposition modelling printer. The viability and proliferation of cells was analyzed by WST-1 assay on days 1 and 3. The cell adhesion was evaluated by scanning electron microscopy (SEM) on days 1 and 3. The cell morphology was examined by hematoxylin and eosin (H&E) staining. Expression of type IV collagen was analyzed by immunohistochemical (IHC) staining. The viability of HDFs on 3D TPU scaffolds was lower than their control groups on days 1 and 3, slightly higher on day 3. SEM images showed HDF attachment to the 3D TPU scaffold surface with spindle-shaped morphology. H&E staining demonstrated that HDFs on 3D TPU scaffolds showed smaller morphologies on days 7 and 14 compared to days 1 and 3. Type IV collagen staining was more intense in HDFs on 3D TPU scaffolds on day 1, 3, and 7 compared to day 14. In conclusion, our study shows the biocompatibility and the potential applications of 3D printed TPU scaffolds for skin tissue engineering using fibroblasts.