The role of printing parameters and scaffold biopolymer properties in the efficacy of a new hybrid nano-bioprinting system.

Abstract

We created a hybrid nano-bioprinting system, which combines the initial patterning capabilities of direct cell writing with the active patterning capabilities of superparamagnetic nanoparticles. Biofabrication conditions, including printing parameters and scaffold biopolymer properties, may affect cell viability, nanoparticle manipulation and patterning capabilities. Nanoparticles were printed under varied conditions either in the biopolymer or loaded inside cells. Cell viability, alginate viscosity, nanoparticle movement and printing resolution were measured. We now show that while nanoparticles decreased cell viability, nozzle size had no significant effect. High printing pressure decreased cell viability, but viability loss was not accentuated by nanoparticles. High nanoparticle concentrations increased alginate viscosity at higher alginate concentrations. Nanoparticle velocity in response to a magnetic field was a function of nanoparticle diameter and scaffold viscosity, which agreed with a mathematical model of nanoparticle movement. Finally, the nano-bioprinting system resolution and patterning precision were not affected by nanoparticles in the prepolymer solution. These data suggest that nanoparticle incorporation in solid freeform fabrication does not change biofabrication parameters unless high nanoparticle concentrations are used. Future work includes developing vascularized tissue engineering constructs using the nano-bioprinting system.