Extrusion bioprinting device for planar and non-planar mammalian cells and bacterial scaffolds prototyping

Purpose This study aims to develop and validate an integrated extrusion bioprinting system that produces planar and non-planar scaffolds with embedded living material (bacteria or mammalian cells), overcoming the limitation of traditional extrusion bioprinting, where the material is deposited and cultured in planar layers. Design/methodology/approach The bioprinting device was constructed by modifying a fused deposition modelling 3D printer, adapting the extrusion holder for hydrogel-bioinks, going from an 8-bit architecture to a 32-bit one andad hoc updating the firmware, increasing the processing capacity and enabling accurate deposition of material. The device performance was assessed in hydrogel 3D planar and non-planar extrusion, considering different radius of curvature to form porous scaffolds, evaluating their ability to retain the designed curved geometry and the cell viability maintaining in bacterial and mammalian cells bioinks. Findings The viability (up to 99%) and growth of bacteria and mammalian cells embedded in the scaffolds was confirmed by confocal microscopy. The suggested bioprinting platform and procedure integrates an efficient strategy for producing hydrogel-based scaffolds, obtaining 98% resolution in planar deposition. For non-planar scaffolds, it was found that they are capable of maintaining the designed curvature even after being removed from the support, with an 88% of resolution. Originality/value It is reported a novel and advanced 3D extrusion bioprinting strategy for producing curved and complex scaffolds, preserving resolution and sterile conditions, introducing in addition a methodology for direct design and generation of a g-code with continuous and smooth paths, pioneering on the 3D bioprinting of bacterial bioinks.