3D alginate constructs for tissue engineering printed using a coaxial flow focusing microfluidic device

This paper describes a novel method of fabricating three dimensional (3D) hydrogel structures primarily for use in tissue engineering. A microfluidic chip capable of coaxial flow focusing is fabricated to crosslink a solution of the hydrogel sodium alginate using a calcium chloride sheath fluid. The sodium alginate rapidly gels and is dispensed from the chip as a fibre. The chip is synchronized with a 3D positioning system to deposit the fibres in a controlled pattern and stack them to form 3D constructs. Furthermore, a 3D printing process is used to fabricate the coaxial flow focusing microfluidic chips, providing a simple means of producing cylindrical channel geometries.