Alendronate reinforced polycaprolactone-gelatin-graphene oxide: A promising nanofibrous scaffolds with controlled drug release

Graphene oxide-reinforced electrospun scaffolds have attracted the attention of many researchers to be served in biomedical applications such as tissue engineering and drug delivery. In this study, the nanofibrous scaffolds were fabricated from polycaprolactone (PCL), gelatin (Gel) and modified-graphene oxide nanoparticles (GO NPs) to investigate their possible application in bone tissue engineering. Alendronate (Ald.), as a bisphosphonate drug, was immobilized covalently (Gel/PCL-GO-Ald.) and non-covalently (Gel/PCL-GO*Ald.) on the modified GO surface. The modified GO NPs were characterized by FTIR, XRD, XPS, FESEM, TEM, and HRTEM analyses. The incorporation of GO in the nanofibrous scaffolds improves the electrical conductivity, swellability, and mechanical strength of the fibers, which were investigated in this work. In vitro drug delivery of alendronate on both Gel/PCL-GO-Ald. and Gel/PCL-GO*Ald., as a drug delivery model, were examined based on a colorimetric assay. Gel/PCL-GO-Ald. hybrid nanofibers revealed good biocompatibility in the presence of human osteosarcoma cells, and no trace of cellular toxicity was observed. Cell culture was monitored by FESEM, XRD (before and after cell culture), and fluorescence analyses, which showed that the cells grown on the scaffolds exhibited a spindle-like and broad morphology, and covered almost the entire fibrous surface uniformly. The scaffolds showed antibacterial activity against E. Coli and S. aureus bacterial strains. Toxicity and biocompatibility of the scaffolds were investigated by MTT analysis. The response of the scaffolds to hemolysis of red blood cells was also studied.