Improving mechanical properties of alginate hydrogel by reinforcement with ethanol treated polycaprolactone nanofibers

Abstract

Hydrogels offer interesting possibilities in various biomedical applications, including tissue regeneration, drug delivery, and cell therapy, due to excellent biocompatibility and good nutrient and oxygen transportation abilities. However, most of these applications require improvements in mechanical properties and functionalization. In this study, a novel technique for fabricating 3D nanofiber-reinforced hydrogel composites is described as a means of enhancing the strength and durability of hydrogels. The method is based on the layer-by-layer electrospinning of nanofibers on an evenly spread, thin hydrogel solution. A coaxial nozzle was introduced for electrospinning highly wettable ethanol-treated nanofibers. This process enhanced the compatibility between the nanofiber reinforcements and the hydrogel matrix. The compressive strength and stiffness of the resulting nanofiber-reinforced hydrogel composites were enhanced to similar to 221% and similar to 434% compared to the pure hydrogel, respectively. Moreover, the equilibrium modulus was increased by a factor of nearly 1.73 when the volume fraction of nanofibers was 0.085. It was demonstrated that a 3D nanofiber-reinforced hydrogel composite could be fabricated without the cumbersome stacking of hydrogel-coated fiber meshes. Furthermore, the mechanical properties of the reinforced composites can be modulated by adjusting the volume fraction of nanofibers. (c) 2012 Elsevier Ltd. All rights reserved.