Pressure assisted multi-syringe single nozzle deposition system for manufacturing of heterogeneous tissue scaffolds

This research focuses on the development of a layered-based novel fabrication methodology for three-dimensional tissue scaffolds with heterogeneous structure of varying concentrations of drug molecules and/or multiple biomaterials. A pressure assisted multi-syringe single nozzle deposition (MSSND) system has been developed for the scaffold fabrication. A custom-designed nozzle has been developed to combine the flows from two or more syringes into a mixing chamber. The presented work also details the fluid model for pressure requirements and material volume flow for a biomaterial. Sodium alginic acid is selected as scaffold biomaterial and cross-linked with calcium chloride solution for gelation. The system designed is able to fabricate three-dimensional (3D) structures from hydrogels with varying concentration of drug microspheres depending on the design requirements. Sample scaffolds are successfully fabricated with different nozzles of diameter 100, 150, and 200 mu m with varying porosities. In this research, 3D heterogeneous scaffolds are developed that are capable of releasing proteins and growth factors spatially and temporally in addition to their function as supporting structures.