Synthesis of chlorotoxin functionalized metallic nanoparticles and their in vitro evaluation of cytotoxic effects in nervous system cancer cell lines

The treatment of glioblastoma (GB) and neuroblastoma (NB) remains a challenge, as current chemotherapies are plagued with systemic toxicity, drug resistance, and inadequate blood-brain barrier (BBB) penetration. Therefore, novel therapeutic strategies with high specificity and the capacity to bypass the BBB are required. Chlorotoxin (CTX) selectively targets gliomas and neuroectodermal tumors. Thus CTX-targeted nanoparticles (NPs) can serve as a promising therapeutic strategy for nervous system (NS) cancers. Bimetallic NPs constructed of two metals such as gold-platinum NPs (AuPtNPs) offer improved anticancer properties compared to individual NPs but are limited for investigations in NS tumors. CTX-functionalized monometallic gold NPs (CTX-AuNPs) and bimetallic gold-platinum NPs (CTX-AuPtNPs) were synthesized in this study. The NPs were characterized by Ultraviolet-Visible Spectroscopy (UV-Vis), Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and Fourier Transform Infra-Red Spectroscopy (FTIR). Cytotoxicity of NPs was investigated in cancer (U87 and SH-SY5Y) and non-cancer (KMST-6) cells using the water-soluble tetrazolium (WST)-1 assay. The CTX-AuNPs and CTX-AuPtNPs had a core size of ~5 nm. The CTX-AuPtNPs showed significant anticancer activity in U87 cells possibly due to the synergistic effects of combined metals. Findings obtained from this study demonstrated that CTX can be used to target NS cancers and that bimetallic NPs could be effective in their treatment. More studies are required to investigate the mechanisms of NPs toxicity, and further explore the hyperthermia treatment of NS cancer using the CTX-AuPtNPs.