Biocompatibility and Delivery of NGF by Hematite Nanotubes for Differentiation of PC12 Cells

This report discusses the compatibility of hematite nanotubes with PC12 cells and the use of these hematite nanotubes to deliver nerve growth factor (NGF) for the differentiation and growth of PC12 cells. The hematite nanotubes used in this work were synthesized using template-assisted thermal decomposition method, followed by dissolving the template. The synthesized hematite nanotubes have a diameter around 200 nm and an average length of about $10μm$⁠, and they have a low coercivity (about 10 Oe) at room temperature. To study the biocompatibility of hematite nanotubes, PC12 cells were cultured in the presence of hematite nanotubes. Neurite (axon and dendrite) outgrowth, formation of morphological connections, and close contacts between PC12 cells and hematite nanotubes unequivocally confirmed the biocompatibility of hematite nanotubes. The efficiency of hematite nanotubes to bind with NGF and the ability of the NGF-incorporated hematite nanotubes to release the bound NGF were also investigated. It is found that NGF-incorporated hematite nanotubes enabled the differentiation of PC12 cells into neurons, and the filopodia extending from growth cones were in close proximity to the NGF-incorporated hematite nanotubes, at times appearing to extend toward or into them. These observations indicate that hematite nanotubes can be used as a vehicle for NGF delivery. This research paves the way toward developing potential treatments using magnetic nanotubes with incorporated growth factors for neurodegenerative disorders and injuries to the nervous system in the future.