Curcumin-enriched Gemini surfactant nanoparticles exhibited tumoricidal effects on human 3D spheroid HT-29 cells in vitro

Here, we examined the tumoricidal effect of Gemini surfactant nanoparticles enriched with curcumin on 3D spheroid HT-29 cells. The delivery of curcumin and other phytocompounds to the tumor niche is an important challenge. Spheroid HT-29 cells were generated by using a conventional hanging drop method and exposed to different concentrations of Gemini-curcumin nanoparticles. The changes in spheroid integrity and cell viability were evaluated by measuring the spheroid diameter and LDH release, respectively. The uptake of Gemini-curcumin nanoparticles was detected by flow cytometry assay. Flow cytometric of Rhodamine 123 efflux was also performed. Migration capacity was analyzed using a Transwell insert assay. By using real-time PCR analysis and Western blotting, we studied the expression level of MMP-2, -9, Vimentin, and E-cadherin genes. Gemini-curcumin nanoparticles had the potential to disintegrate spheroids and decrease central density compared to the control group (p < 0.05). These changes coincided with enhanced LDH release by the increase of nanoparticle concentration (p < 0.05). Data highlighted the ability of cells to uptake synthetic nanoparticles in a dose-dependent manner. We found reduced Rhodamine 123 efflux in treated HT-29 spheroid cells compared to the control (p < 0.05). Nanoparticles significantly decreased the metastasis and epithelial-mesenchymal transition (EMT) rate by the suppression of MMP-2 and MMP-9, Vimentin, and induction of E-cadherin (p < 0.05). Our data confirmed that Gemini curcumin has the potential to suppress cell proliferation and inhibit metastasis in 3D spheroid HT-29 cells in vitro.