Preparation and characterization of dexamethasone loaded sodium alginate-graphene oxide microspheres for bone tissue engineering

Over 2.2 million bone graft transplantations are performed by clinicians worldwide annually. The development of synthetic bone graft substitute for the treatment of bone defects is still an utmost challenge in bone tissue engineering. In the current study, we have fabricated calcium ion cross-linked alginate (Alg), alginate-graphene oxide (Alg-GO) and alginate-graphene oxide-dexamethasone (Alg-GO-Dex) composite microspheres as an alternative bone graft substitute. Various properties of developed microspheres were investigated using appropriate characterization tools including Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy combined with energy dispersive X-ray diffraction. In vitro biomineralization study was performed using simulated body fluid (SBF) solution. Biocompatibility of the developed microspheres was studied with osteoblast-like cells (MG-63). The developed microspheres showed more than 80% of porosity and dispersion of GO in the alginate matrix was uniform. The size of developed microspheres is in the range of 1.5 +/- 0.5 mm, and Dex drug was released from the microspheres in sustainable manner. Excellent apatite formation was observed on the surface of the microspheres using SBF solution which is useful for bone tissue regeneration. In vitro studies using osteoblast like MG-63 cells revealed profound biocompatibility. Thus, the developed AlgGO-Dex composite microspheres have potential applications in drug delivery system towards bone tissue engineering applications.