3D bioprinting with high-viscosity bioinks: A custom-designed extrusion head for high-resolution cellulose acetate scaffolds

Additive manufacturing holds significant potential in the field of tissue engineering, particularly for healing, replacing, and regenerating damaged or diseased tissues. However, the high cost of commercially available bioprinters and the limited availability of suitable biomaterials for bioprinting have hindered its widespread implementation and practical application in clinical settings. The aim of this study was to identify printing parameters tailored to the viscosity of the bioink and the evaporation characteristics of the organic solvent used in its formulation, with the broader goal of developing a cost-effective and accessible bioprinting platform for scaffold fabrication. To this end, we present a novel approach involving the design and fabrication of a cost-effective three-dimensional (3D) bioprinter conversion kit, developed using commercially available 3D printers. Bioprinting high-viscosity bioinks present specific challenges due to their resistance to flow and a high tendency to clog printing nozzles; however, this issue was mitigated through comprehensive rheological characterization. By leveraging the favorable properties of cellulose acetate as the chosen biomaterial, scaffold fabrication via 3D bioprinting was achieved efficiently without the need for curing or post-processing steps. Furthermore, a parametric troubleshooting procedure was developed to optimize printing parameters, elucidate the material behavior, and improve scaffold resolution, as assessed through scanning electron microscopy. Additionally, preliminary cell culture studies were carried out to evaluate the influence of the printed scaffolds’ biophysical cues on cellular responses, including adhesion and proliferation. This innovative and cost-effective solution has great potential to support researchers in tissue engineering and facilitate further exploration of advanced bioprinting techniques.