Cyclic hexapeptide-conjugated nanoparticles enhance curcumin delivery to glioma tumor cells and tissue

Glioma has one of the highest mortality rates among primary brain tumors. The clinical treatment for glioma is very difficult due to its infiltration and specific growth locations. To achieve improved drug delivery to a brain tumor, we report the preparation and in vitro and in vivo evaluation of curcumin nanoparticles (Cur-NPs). The cyclic hexapeptide c(RGDf(N-me) VK)-C (cHP) has increased affinity for cells that overexpress integrins and was designed to target Cur-NPs to tumors. Functional polyethyleneglycol-modified poly(d,l-lactide-co-glycolide) (PEG-PLGA) conjugated to cHP was synthesized, and targeted Cur-NPs were prepared using a self-assembly nanoprecipitation process. The physicochemical properties and the in vitro cytotoxicity, accuracy, and penetration capabilities of Cur-NPs targeting cells with high levels of integrin expression were investigated. The in vivo targeting and penetration capabilities of the NPs were also evaluated against glioma in rats using in vivo imaging equipment. The results showed that the in vitro cytotoxicity of the targeted cHP-modified curcumin nanoparticles (cHP/Cur-NPs) was higher than that of either free curcumin or non-targeted Cur-NPs due to the superior ability of the cHP/Cur-NPs to target tumor cells. The targeted cHP/Cur-NPs, c(RGDf(N-me)VK)-C-modified Cur-NPs, exhibited improved binding, uptake, and penetration abilities than non-targeting NPs for glioma cells, cell spheres, and glioma tissue. In conclusion, c(RGDf(N-me)VK)-C can serve as an effective targeting ligand, and cHP/Cur-NPs can be exploited as a potential drug delivery system for targeting gliomas.