Development of Nanofiber-Reinforced Hydrogel Scaffolds for Nucleus Pulposus Regeneration by a Combination of Electrospinning and Spraying Technique

In this work a new method is presented to efficiently produce hydrogel scaffolds reinforced with nanofibers to show enhanced mechanical properties and improved structural integrity. The method is based on a combination of air brush spraying of a hydrogel and electrospinning of nanofibers. With air brush spraying the controllability is enhanced and the potential for scale-up increased. The developed method was used to successfully reinforce gellan gum hydrogels with electrospun polycaprolactone nanofibers. Optical and rheological evaluations were performed and showed that parameters such as the amount of incorporated nanofibers, gellan gum concentration and calcium chloride (crosslinker) concentrations could be used to modulate material properties. Incorporation of a small amount of nanofibers had a reinforcing effect and resulted in a hydrogel with rheological properties similar to the human nucleus pulposus (NP). The method is flexible and carries potential for designing scaffolds for e.g. NP tissue regeneration.