Development and Characterization of Nanofiber-Reinforced Hydrogel for Bone Regeneration

Bone tissue is a type of composite material that is composed of both organic and inorganic materials, constantly expose various deforming forces. Bone regeneration occurs through a complex system of induction and conduction of various signals inside and outside the tissue, migration and activation of bone forming and bone deforming cells. In clinical studies, this process is achieved either forcing the osteogenesis process by surgical operation or using different types of grafts. Also, hydrogels are preferred due to their ability to initiate and support bone regeneration in various ways, such as carrying growth factors, providing a constriction similar to ECM, easy to control their degradation kinematic and the biocompatible nature. However, due to their high water content, mechanical strength decreases and results in a poorly executed bone regeneration process. In this study, hydrogel structures that is reinforced by nanofiber (NF) sheets were produced to overcome mechanical strength related problems. After poly (lactic-co-glycolic acid) (PLGA) NFs were produced with electrospinning technique, PEGDA (Poly(ethylene glycol) diacrylate) hydrogel structures were produced by using layer-by-layer method and reinforced by the NF sheets within the hydrogel layers. Our results indicate that cell viability and cell proliferation within the fiber-reinforced structures increased through 7 days and cell number was significantly higher compared to only hydrogel containing layered structure. Furthermore, NF-reinforced hydrogel structures and structures containing only PEGDA were tested mechanically, the mechanical strength of the NF reinforced hydrogel was higher compared to control group. In conclusion, NF-reinforced hydrogel structures are promising for bone regeneration in future.