Development and optimization of a new hybrid chitosan-grafted graphene oxide/magnetic nanoparticle system for theranostic applications

There is currently a great demand especially in cancer treatment for transformative theranostic technologies combining imaging with drug delivery. This study reports the design and optimization of a hybrid theranostic nano-system combining the imaging capabilities of magnetic nanopartides (MNPs) with the great potential of chitosan-grafted graphene oxide (GO) as a pH-sensitive smart nano-carrier, using different molecular weights and concentrations of chitosan. The loading and release behavior, biocompatibility, and magnetic properties of the MNP/GO/chilosan nano-system were experimenlaly evaluated with a chemottherapy drug, Doxorubicin through a range of analytical methods. Increased pH resulted in a reduction in the rate of doxorubicin release, suggesting the formation of hydrogen bonds and the physical prevention of collapsed chitosan chains. In addition, a decrease in chitosan molecular weight, and an increase in concentration reduced the doxorubicin loading in around 24% yet a decrease in molecular weight increased the released amount in more than 200%. This has been related to fewer hydrogen binding and more contribution of pi-pi stacking in doxorubicin-chitosan interactions.The 12 contrast efficacy increased by grafting MNP/GO with high molecular weight chitosan due to the better surface coverage. Cytotoxicity assays with healthy L929 cell lines revealed high biocompatibility of MNP/GO/chitosan nano-system, suggesting chitosan prevents GO contact with the cell membrane. Further assays carried out with cancer cells MCF7 with MNP/GO/chitosan loaded with doxorubicin showed improved performance for MNP/GO grafted with low molecular weight chitosan. On the overall, the hybrid MNP/GO grafted with high molecular weight chitosan at 6.0 g/dl showed optimal properties for theranostic applications. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A hybrid theranostic nano-system was designed with magnetic nanoparticles and chitosan-grafted graphene oxide to combine imaging and drug delivery capabilities for cancer treatment. Experimental evaluation showed high biocompatibility, optimal loading and release behavior, and improved therapeutic performance against cancer cells, suggesting potential for theranostic applications.