Optimization of electrohydrodynamic writing technique to print collagen

Electrohydrodynamic (EHD) printing can be used as a writing technique to print collagen, as outlined by a recent study. The materials used include glass microscope coverslips, collagen solution, an equipment for printing that is composed of syringe pump, charge-coupled device imaging system, power supply and stage controller and HeLa cells and HEK293 cells cultured under standard conditions. Coverslips were treated with piranha solution to remove organic residues from the glass substrates, while the collagen was purified from a rat tail. In printing, a positive electric potential was applied to the stainless steel nozzle which also move in the X-Y direction. By changing parameters such as DC voltage, composition of electrolyte and distance between nozzle and substrate EHD patterning on collagen by means of a computer software. Hela cells were placed at the collagen pattern substrate. Results show that the major strength of EHD include distribution of fine droplets, direct operation of the printing system, rapid, cost effective and can be used to locate animal cells.