Optimization of FDM 3D printing process parameters to produce haemodialysis curcumin-loaded vascular grafts

3D printing has provided a new prospective in the manufacturing of personalised medical implants, including fistulas for haemodialysis (HD). In the current study, an optimized Fused Modelling Deposition (FDM) 3D printing method has been validated, for the first time, to obtain cylindrical shaped fistulas. Printing parameters were evaluated for the manufacturing of fistulas using blank and 0.25 % curcumin-loaded filaments that were produced by Hot Melt Extrusion (HME). Four different fistula types have been designed and characterised using a variety of physicochemical characterisation methods. Each design was printed three times to demonstrate printing process accuracy considering outer and inner diameter, wall thickness, width, and length. A thermoplastic polyurethane (TPU) biocompatible elastomer was chosen, showing good mechanical properties with a high elastic modulus and maximum elongation; as well as stability at high temperatures with less than 0.8 % of degradation at the range between 25 – 250 °C. Curcumin release profile has been evaluated in a saline buffer, obtaining a low release (12 %) and demonstrating drug could continue release for a longer period, and for as long as grafts should remain in patient body. Possibility to produce drug-loaded-grafts using one-step method as well as 3D printing process and TPU filaments containing Curcumin printability has been demonstrated.