Zinc oxide/clove essential oil incorporated type B gelatin nanocomposite formulations: A proof-of-concept study for 3D printing applications

Bioactive bovine skin gelatin (BSG)/zinc oxide (ZnO)/clove essential oil (CEO) nanocomposites films were fabricated by a solution-cast. The suitable combinations of ZnO (2 wt%) and CEO (25 wt%) improve the desirable film properties, namely, elongation at break (EAB), optical, structural, thermal, barrier and microbiological properties. XRD confirmed the presence of ZnO in the gelatin-composites and the highest thermal stability of the composites was evident by the TGA thermograms. Currently, additive manufacturing has received serious attention in the development of complex structures in the tissue engineering and allied areas, with tailored properties. In this work, the optimized formulation was further explored for its potential applications in 3D (bio) printing. The BSG/ZnO/CEO blend was converted into a semi-solid viscous mass by means of a twin-screw extrusion process. The extruded materials were utilized further to develop 3D printable bioinks in the presence of sodium alginate polymer. Round shaped thin alginate-based films (D x H = 10 mm x 1 mm) were printed via a commercial 3D printer (cross-linked with 100 mM CaCl2 solution). This technique could bring advantages and superiority over the conventional processes, with the competence of generating reproducible, tailored, and functional structures, which could effectively endorse regeneration of different tissues and can be used across the disciplines including food packaging and food printing.