Effect of Capsaicin-Loading Nanoparticles on Gliomas

Capsaicin is recognized as a natural tumor preventive compound and exhibits a remarkable anticancer action. Strong inhibitory role of capsaicin on gliomas has been well documented. However, the use of capsaicin is limited due to its hydrophobicity, low affinity, and short half-life. The present study aimed to explore the physiochemical characteristics of the capsaicin-loading nanoparticles prepared by methoxy polyethylene glycol-poly(caprolactone) (mPEG-PCL) amphiphilic block copolymer. It also aimed to evaluate the ability of the nanoparticles to cross the blood-brain barrier. Additionally, the uptake of nanoparticles in the glioma cells and its ability to inhibit cell proliferation were tested in human glioblastoma U251 cells. mPEG-PCL amphiphilic block copolymer was synthesized using the ring-opening polymerization method, and the capsaicin-loading nanoparticles were prepared with the solvent diffusion method. In vitro drug release assay revealed that the capsaicin-loading nanoparticles presented a slow-release characteristic. Coculture of the human glioblastoma U251 cells and the fluorescein-loading nanoparticles showed the uptake of nanoparticles in U251 cells by endocytosis. We found that the NIR-797 isothiocyanate-loading nanoparticles can cross the blood-brain barrier. In addition, the capsaicin-loading nanoparticle showed a remarkable inhibition on the growth of U251 cells. The efficacy of the capsaicin-loading nanoparticles against tumor cells was significantly superior to the capsaicin at low concentrations. It is concluded that the capsaicin-loading nanoparticles can provide an extremely promising approach for chemotherapy of gliomas.