| Chitosan has been used for a wide range of biomedical applications because of its satisfactory biocompatibility. Experimental results demonstrated that chitosan exhibited anti-microbial activities through its interaction(s) with microbial cell surface. We hypothesized that the properties of chitosan can be exploited to inhibit cancer cell growth. The commercial use of nanomaterials such as carbon nanotubes (CNTs) and nanoparticles (e.g., silver and gold nanoparticles) for novel applications is increasing exponentially. However, the impact of these nanomaterials on human and environmental health remains unclear. In this study, we investigated the effects of chitosan, chitosan in combination with nanoparticles, and chitosan in combinations with nanoparticles and/or three therapeutic drugs (i.e., Adriamycin, Methotrexate, and Cisplatin) on human brain glioblastoma U87 cells. We also investigated the effects of functionalized (i.e., carboxylated and hydroxylated), non-functionalized short multi-walled carbon nanotubes (SMWCNTs), chitosan, and chitosan in combination with SMWCNTs on dorsal root ganglion (DRG) neurons which constitute an excellent model in vitro of neurons derived from the peripheral nervous system (PNS). The close interactions between DRG neurons and Schwann cells stimulated us to develop a co-culture model consisting of DRG neurons and Schwann cells to investigate our hypothesis that co-culturing DRG neurons with Schwann cells imparts protection on them against cytotoxicity induced by silver or gold nanoparticles. The results of this project contribute significantly to the applications of chitosan and nanoparticles in tissue engineering, cancer therapy, and improve our understanding of how exposure to CNTs and silver and gold nanoparticles impacts the PNS and mechanisms underlying DRG neurons-Schwann cells interactions. |