Dual drug spatiotemporal release from functional gradient scaffolds prepared using 3D bioprinting and electrospinning

Functional gradient scaffolds play an important role in osteochondral tissue engineering because they can meet the essential requirement for a gradual transition of both physical and chemical properties in osteochondral tissue regeneration. There is a requirement for 3D composite osteochondral regeneration scaffolds with multiscale structures that are capable of controlling release of multiple biomolecules. To this end, this article describes a 3D bioprinting platform integrated forming system designed to produce various drug‐loaded scaffolds. A novel scaffold was fabricated by the self‐developed 3D bioprinting platform combining extrusion deposition with multi‐nozzle electrospinning. For temporally controlled release of gentamycin sulfate (GS) and desferoxamine (DFO), blend electrospun GS/polyvinyl alcohol (PVA) and coaxial electrospun core (PVA‐DFO)/shell (polycaprolactone; PCL) fibers were deposited in the scaffold. After a 25‐day time‐lapse release study in vitro, results showed GS released faster than DFO during the early stages and sustained release of DFO for long periods. For spatially controlled release of DFO, the vertically gradient gelatin/sodium alginate (SA) scaffolds presented to enable the release amount of DFO in a gradient mode. The experiment and test results demonstrate the validity of the 3D bioprinting platform integrated forming system and the excellent properties of such scaffolds for performing multidrug spatiotemporal release. POLYM. ENG. SCI., 56:170–177, 2016. © 2015 Society of Plastics Engineers