High-performance coaxial 3D printing towards emulsion-Vitamin D formability

As an advanced mode of coaxial 3D printing, its outer layer can be designed to shape a soft 2D inner core to a strong stereoscopic structure. Here, we used oil-based Pickering emulsions stabilized by starch nanoparticle as the inner core, with carrageenan gel as the outer layer. Emulsion cores with different rheological properties greatly influence the overall printability (especially 70% oil content), which have been complemented by fluid dynamics simulation of pressure and velocity distributions (at the ratio of inner core to outer layer of 2:3). Vitamin D (V_D) was used as a functional additive embedded into different emulsions of inner cores and protected both by the inner and the outer layers. Particle size and stability analyses demonstrated that emulsions loaded with V_D (even higher than 90% with the protection of outer layer after 15 days) still had a stabilized system.